Timeline of the xz open source attack

1069 points17
gawa17 days ago

Excellent summary of the events, with all the links in one place. This is the perfect resource for anyone who want to catch up, and also to learn about how such things (especially social engineering) unfold in the wild, out in the open.

One thing that could be added, for the sake of completeness: in the part "Attack begins", toward the end, when they are pushing for updating xz in the major distros, Ubuntu and Debian are mentioned but not Fedora.

Looks like the social engineering/pressuring for Fedora started at least weeks before 2024 March 04, according to a comment by @rwmj on HN [1]. I also found this thread on Fedora's devel list [2], but didn't dig too much.



sfjailbird16 days ago

It would be intetesting if Lasse Collin published his off-list interactions with 'Jia Tan' and any of the other pseudonyms, to get an even better angle on the social engineering parts. Apparently a large part of the campaign was via private channels to Lasse.

publius_0xf316 days ago

Collin has been writing more extensively on IRC. A screenshot of one of his posts can be seen in [this YouTube video](

He notes that while he was unsatisfied with some of the changes Tan introduced, Tan was nonetheless extremely helpful.

runeks16 days ago

> [...] unsatisfied with some of the changes Tan introduced [...]

That's one way to put it

larntz16 days ago

I was wondering if that would be released also. I hope so but wouldn't blame them if they decide not to.

bigiain16 days ago

I wouldn't blame then if they've thrown all their computers into the sea, changed their name, and taken upon a job building timber furniture...

jtriangle16 days ago

I, too, have had days like that

jaystraw15 days ago

as an alaskan, those aren't mutually exclusive

rwmj17 days ago

Missing the whole Fedora timeline. I was emailed by "Jia Tan" between Feb 27 and Mar 27, in a partially successful attempt to get the new xz into Fedora 40 & 41. Edit: I emailed Russ with the details.

itslennysfault17 days ago

I wondered about this. I saw the note at the bottom "RedHat announces that the backdoored xz shipped in Fedora Rawhide and Fedora Linux 40 beta" but saw nothing in the timeline explaining when/how it made it into Fedora.

rwmj17 days ago

These are the Fedora packages for xz that are vulnerable. If you click through the links you can see when they were added: (

This is the rough sequence of events in Fedora: (

psanford17 days ago

One big take away for me is that we should stop tolerating inscrutable code in our systems. M4 has got to go! Inscrutable shell script have got to go!

Its time to stop accepting that the way we've done this in the past is the way we will continue doing it ad infinitum.

kibwen17 days ago

That's a great first step, but ready your pitchforks for this next take, because the next step is to completely eliminate Turing-complete languages and arbitrary I/O access from standard build systems. 99.9% of all projects have the capability to be built with trivial declarative rulesets.

hyperman117 days ago

Java's Maven is an interesting case study, as it tried to be this:. A standard project layout, a standard dependency mechanism, pom.xml as standard metadata file, and a standard workflow with standard target(clean/compile/test/deploy). Plugins for what's left.

There might have been a time where it worked, but people started to use plugins for all kinds of reasons, quite good ones in most cases. Findbugs, code coverage, source code generation,...

Today, a maven project without plugins is rare. Maven brought us 95%, but there is a long tail left to cover.

wongarsu17 days ago

Most of these could still be covered with IO limited to the project files though.

There is a sizable movement in the Rust ecosystem to move all build-time scripts and procedural macros to (be combined to) WASM. This allows you to write turing-complete performant code to cover all use-cases people can reasonably think of, while also allowing trivially easy sandboxing.

It's not perfect, for example some build scripts download content from the internet, which can be abused for information extraction. And code generation scripts could generate different code depending on where it thinks it's running. But it's a lot better than the unsandboxed code execution that's present in most current build systems, without introducing the constraints of a pure config file.

comex17 days ago
RedShift117 days ago

How does the sandboxing help if the compiler and/or build scripts or whatever modifies its own output?

shawnz17 days ago

When your programmatic build steps are isolated in plugins, then you can treat them like independent projects and apply your standard development practices like code review and unit tests to those plugins. Whereas when you stuff programmatic build steps into scripts that are bundled into existing projects, it's harder to make sure that your normal processes for assuring code quality get applied to those pieces of accessory code.

dotancohen17 days ago
ptx17 days ago

Maybe now that we have things like GitHub Actions, Bitbucket Pipelines, etc., which can run steps in separate containers, maybe most of those things could be moved from the Maven build step to a different pipeline step?

I'm not sure how well isolated the containers are (probably not very – I think GitHub gives access to the Docker socket) and you'd have to make sure they don't share secret tokens etc., but at least it might make things simpler to audit, and isolation could be improved in the future.

kibwen17 days ago

> Findbugs, code coverage, source code generation,...

For the purpose of this conversation we mostly just care about the use case of someone grabbing the code and wanting to use it in their own project. For this use case, dev tools like findbugs and code coverage can be ignored, so it would suffice to have a version of the build system with plugins completely disabled.

Code generation is the thornier one, and we can at least be more principled about it than "run some arbitrary code", and at least it should be trivial to say "this codegen process gets absolutely no I/O access whatsoever; you're a dumb text pipeline". But at the end of the day, we have to Just Say No to things like this. Even if it makes the codebase grodier to check in generated code, if I can't inspect and audit the source code, that's a problem, and arbitrary build-time codegen prevents that. Some trade-offs are worth making.

hyperman117 days ago
koito1717 days ago

In this case, I think the GP is absolutely right. If you look at the infamous patch with a "hidden" dot, you may think "any C linter should catch that syntax error and immediately draw suspicion." But the thing is, no linter at the moment exists for analyzing strings in a CMakeLists.txt file or M4 macro. Moreover, this isn't something one can reliably do runtime detection for, because there are plenty of legitimate reasons that program could fail to compile, but our tooling does not have a way to clearly communicate the syntax error being the reason for a compilation failure.

fl730516 days ago

> there are plenty of legitimate reasons that program could fail to compile

It's worse than that, these small C files are required to fail unless the target build environment meets some specific requirements.

jononor14 days ago
duped17 days ago

What would that accomplish? It certainly wouldn't have stopped this attack.

> 99.9% of all projects have the capability to be built with trivial declarative rulesets.

Only if you forbid bootstrapping, which all projects ultimately rely on at some point in their supply chain.

kibwen16 days ago

> What would that accomplish? It certainly wouldn't have stopped this attack.

We could write an entire PhD thesis on the number of dire technical failings that would need to be addressed to stop this attack, so while this alone wouldn't have stopped it, it would have required the actor to come up with another vector of code injection which would have been easier to find.

> Only if you forbid bootstrapping

Codebases that bootstrap are the 0.1%. Those can be built via `bash` rather than deceptively hiding a Turing-complete environment behind a declarative one. Even if you need to have these in your trusted computing base somewhere, we can focus auditing resources there, especially once we've reduced the amount of auditing that we need to do on the other 99.9% of codebases now that we've systematically limited the build-time shenanigans that they can get up to.

duped16 days ago

Concretely, what security issues are solved by forcing the build specification language to be Turing incomplete? My guess is the answer is "none."

At worst, you're actually creating more holes. The reason autoconf/automake exist and M4 scripts are innocuous in the first place is because the build system uses an underpowered language and developers have to turn to code generation to get around it.

If you kneecap the build system's language you're not solving problems. You're creating them.

> it would have required the actor to come up with another vector of code injection which would have been easier to find.

If make was standardized and could programmatically determine the environment its run under and write full programs then the attack vector wouldn't exist in the first place.

> Codebases that bootstrap are the 0.1%.

We have different experiences, because ime it's close to 100% especially when you include transitive dependencies. When you care about supply chain security you care about being able to bootstrap from sources for your code and all your dependencies, and it's almost guaranteed that one of your dependencies needs to be bootstrapped.

eadmund17 days ago

I think that what we need is good sandboxing. All a sandboxed Turing-complete language can do is perform I/O on some restricted area, burn CPU and attempt to escape the sandbox.

I would like to see this on the language level, not just on the OS level.

semi-extrinsic17 days ago

I have been thinking the exact same thing, and specifically I would like to try implementing something that works with the Rye python manager.

Say I have a directory with a virtualenv and some code that needs some packages from PyPI. I would very much like to sandbox anything that runs in this virtualenv to just disk access inside that directory, and network access only to specifically whitelisted URLs. As a user I should only need to add "sandbox = True" to the pyproject.toml file, and optionally "network_whitelist = [...]".

From my cursory looking around, I believe Cloudflare sandbox utils, which are convenience wrappers around systemd Seccomp, might be the best starting point.

Edit: or just use Firejail, interesting...

You mention sandboxing on the language level, but I don't think it is the way. Apparently sandboxing within Python itself is a particularly nasty rabbit hole that is ultimately unfruitful because of Python's introspection capabilities. You will find many dire warnings on that path.

azemetre17 days ago

Can you explain more in-depth what you mean? I'm also unaware of how you could have declarative rulesets in a non turing-complete language.

Sounds like it would be impossible but maybe my thinking is just enclosed and not free.

ngruhn17 days ago

Haven’t used it much but Dhall is a non Turing complete configuration language:

smallmancontrov17 days ago

What does modern C project management look like? I'm only familiar with Autotools and CMake.

infamouscow17 days ago

Redis. Simple flat directory structure and a Makefile. If you need more, treat it as a sign from God you're doing something wrong.

cryptonector17 days ago

This is a better take. Though I'm sure people can obfuscate in source code just as much as in build configuration code.

klysm17 days ago

until you have to integrate with the rest of the world sure

kibwen17 days ago

Looking at the state of software security in the rest of the world, this may not be much of a disincentive. At some point we need to knuckle down and admit that times have changed, the context of tools built for the tech of the 80s is no longer applicable, and that we can do better. If that means rewriting the world from scratch, then I guess we better get started sooner rather than later.

orthecreedence17 days ago

This doesn't read as a technical failure to me. This was 99% social engineering. I understand that the build system was used a vector, but eliminating that vector doesn't mean all doors are closed. The attacker took advantage of someone having trouble.

pera17 days ago

While I do agree that M4 is not great I don't believe any alternative would have prevented this attack: you could try translating that build-to-host file to say python with all the evals and shell oneliners and it would still not be immediately obvious for a distro package maintainer doing a casual review after work: for them it would look just like your average weekend project hacky code. Even if you also translated the oneliners it wouldn't be immediately obvious if you were not suspicious. My point is, you could write similarly obfuscated code in any language.

cryptonector17 days ago

What's inscrutable code? Was it m4 or sh or the combination of the two?

Who will pay for all the rewriting you want done? Or even just for the new frameworks that are "scrutable"? How do we guarantee that the result is not inscrutable to you or others?

There is so much knee-jerking in this xz debacle.

(And I say this / ask these questions with no love for autoconf/m4/sh.)

psanford16 days ago

I think this is pretty straight forward. Don't accept PRs for code that cannot be reasoned about easily.

hinkley16 days ago

We are all paying right now for it not being done.

hinkley16 days ago

I do think we have enough eyeballs at this point that we should stop entertaining the Dancing Bear in low level libraries and start insisting on crisp, self-explaining code. There are a lot of optimizations pushed into compilers these days, and there are a lot of architectural changes that can make things fast without making them inscrutable.

We should be moving from No Obvious Bugs to Obviously No Bugs (Tony Hoare).

l33t733227316 days ago

>start insisting on crisp, self-explaining code

That’s the beauty of FOSS: if you don’t like what’s written, you can write your own replacement.

hinkley15 days ago

And now we have 14 standards.

tomxor17 days ago

That would be an improvement for sure... but this is not fundamentally a technical problem.

Reading the timeline, the root cause is pure social engineering. The technical details could be swapped out with anything. Sure there are aspects unique to xz that were exploited such as the test directory full of binaries, but that's just because they happened to be the easiest target to implement their changes in an obfuscated way, that misses the point - once an attacker has gained maintainer-ship you are basically screwed - because they will find a way to insert something, somehow, eventually, no matter how many easy targets for obfuscation are removed.

Is the real problem here in handing over substantial trust to an anonymous contributor? If a person has more to lose than maintainership then would this have happened?

That someone can weave their way into a project under a pseudonym and eventually gain maintainership without ever risking their real reputation seems to set up quite a risk free target for attackers.

usefulcat17 days ago

> Is the real problem here handing over substantial trust to an anonymous contributor?

Unless there's some practical way of comprehensively solving The Real Problem Here, it makes a lot of sense to consider all reasonable mitigations, technical, social or otherwise.

> If a person has more to lose than maintainership then would this have happened?

I guess that's one possible mitigation, but what exactly would that look like in practice? Good luck getting open source contributors to accept any kind of liability. Except for the JiaTans of the world, who will be the first to accept it since they will have already planned to be untouchable.

patmorgan2317 days ago

Create an organization of paid professionals who are responsible for maintaining these libraries (and providing support to library users).

It's heartblead all over again (though those were honest mistakes, not an intentional attack

tomxor17 days ago

> I guess that's one possible mitigation, but what exactly would that look like in practice? Good luck getting open source contributors to accept any kind of liability. Except for the JiaTans of the world, who will be the first to accept it since they will have already planned to be untouchable.

It's not necessary to accept liability, that's waived in all FOSS licenses. What I'm suggesting would only risk reputation of non-malicious contributors, and from what I've seen, most of the major FOSS contributors and maintainers freely use their real identity or associate it with their pseudonym anyway, since that attribution comes with real life perks.

Disallowing anonymous pseudonyms would raise the bar quite a bit and require more effort from attackers to construct or steal plausible looking online identities for each attack, especially when they need to hold up for a long time as with this attack.

flockonus17 days ago

Agreed it's mainly a social engineering problem, BUT also can be viewed as a technical problem, if a sufficiently advanced fuzzer could catch issues like this.

It could also be called an industry problem, where we rely on other's code without running proper checks. This seems to be an emerging realization, with services like starting to emerge.

1letterunixname16 days ago

Autotools-based build infra is always crufty, fragile, slow, and fugly. In a lot of cases, it sucks because it's what we have right now without doing the work to replace it with something equally flexible.

Build infrastructure should be minimal, standardized, and not subject to endless special, undocumented fragility.

cmake, just, conan, meson, and bazel (and forks) exist.

But I've still yet to see a proper build system that does feature detection in parallel and concurrently, or supports live, incremental, continuous, cached rebuilding.

intelVISA17 days ago

Functionality like IFUNC is completely inexcusable outside of dev/debug builds imo. It's rot.

patmorgan2317 days ago

That and we need to pay open source maintainers and find new ways to support them.

And all code that gets linked into security critical applications/libraries needs to be covered by under some sort of security focused code review.

So no patching the compression code that openSSL links to with random junk distribution maintainers.

ncruces16 days ago

That's an improvement, but ultimately not enough, actually. The article hits at this, and you should definitely read it:

Being able to send xz patches to the Linux kernel would have been a nice point of leverage for Jia Tan's future work. We're not at trusting trust [1] levels yet, but it would be one step closer.


ok12345617 days ago

With all the CI tooling and containerization, it seems to be going in the opposite direction.

Dalewyn17 days ago


davedx17 days ago

Nonsensical argument. JavaScript and TypeScript projects are developed with patches of the original source not some compressed artefact. Take your trolling elsewhere

Dalewyn17 days ago


mardifoufs16 days ago

Javascript is almost always executed in sandboxed, unprivileged environments. The issue here is that this type of obfuscation is easy to add in core os libraries. The JavaScript ecosystem, for all the hate that it gets, makes it super easy to sandbox any running code.

It doesn't matter if it's minified or obfuscated because you basically have to run unknown, untrusted code everywhere while browsing the web with JavaScript turned on. So the ecosystem and tooling is extremely resilient to most forms of malicious attacks no matter how minified or obfuscated the js you're running is. The complete opposite is true for bash and shell scripting in general

Sammi17 days ago

Javascript is pretty much guaranteed to be permanent. It is the language of the web.

(There's webassembly too, but that doesn't remove js)

homarp17 days ago

I don't think anything is "pretty much guaranteed": things evolve

Sammi16 days ago

Hence the "pretty much".

Dalewyn17 days ago


rurban17 days ago

Great, let the cmake dummies wander off into their own little dreamworld, and keep the professionals dealing with the core stuff.

userbinator17 days ago

I think one of the good things to come out of this may be an increased sense of conservatism around upgrading. Far too many people, including developers, seem to just accept upgrades as always-good instead of carefully considering the risks and benefits. Raising the bar for accepting changes can also reduce the churn that makes so much software unstable.

cesarb17 days ago

> Far too many people, including developers, seem to just accept upgrades as always-good instead of carefully considering the risks and benefits.

Another example of this was log4j: if you were still using the old 1.x log4j versions, you wouldn't have been vulnerable to the log4shell vulnerability, since it was introduced early in the 2.x series. The old 1.x log4j versions had other known vulnerabilities, but only if you were using less common appenders or an uncommon server mode or a built-in GUI log viewer (!); the most common use of log4j (logging into a local file) was not exposed to any of these, and in fact, you could remove the vulnerable classes and still have a functional log4j setup (see for instance which I just found on a quick web search).

Did log4shell (and a later vulnerability which could only be exploited if you were using Java 9 or later, because it depended on a new method which was introduced on Java 9) lead people to question whether always being on the "latest and greatest" was a good thing? No, AFAIK the opposite happened: people started to push even harder to keep everything on the latest release, "so that when another vulnerability happens, upgrading to a fixed version (which is assumed to be based on the latest release) will be easy".

JohnMakin17 days ago

> Another example of this was log4j: if you were still using the old 1.x log4j versions, you wouldn't have been vulnerable to the log4shell vulnerability

Lol, this exact thing happened at my last gig. When I first learned of the vulnerability I panicked, until I found out we were so outdated it didn't affect us. We had a sad laugh about it.

> "so that when another vulnerability happens, upgrading to a fixed version (which is assumed to be based on the latest release) will be easy".

I think there is some truth to this motivation though - if you are on an ancient 1.X version and have to jump a major version of two, that almost always causes pain depending on how critical the service or library is. I don't pretend to know the right answer but I always tend to wait several versions before upgrading so any vulnerabilities or fixes can come by the time I get to the upgrade.

cesarb17 days ago

A lot of people were in that exact same situation. So many, that the original author of log4j 1.x released a fork to allow these people to keep using the old code while technically being "up to date" and free of known vulnerabilities:

darkwater16 days ago

> "so that when another vulnerability happens, upgrading to a fixed version (which is assumed to be based on the latest release) will be easy".

Isn't this still true, generally speaking? How many servers are daily compromised due to out of date, exploitable versions of software versus XZ-like sophisticated attack?

TheKarateKid17 days ago

About a decade ago, the industry shifted from slow, carefully evaluated infrequent updates (except for security) to frequent, almost daily updates that are mandatory. I'd say this was pioneered by the Chromium team and proved to be beneficial. The rest of the industry followed.

Now we're in a position where most projects update so quickly, that you don't really have a choice. If you need to update one component, there's a good chance it will require that many more as dependencies in your project will require an update to be compatible.

The industry as a whole sacrificed stability and some aspects of security for faster advancements and features. Overall I'd say the net benefit is positive, but its times like these that remind us that perhaps we need to slow things down just a little and do a bit of a course correction to bring things into a better balance.

sebstefan17 days ago

All things considered I'm not sure that'd be such a good thing

How many security issues spring from outdated packages vs packages updated too hastily?

Hackbraten17 days ago

On top of that:

A newly-introduced security issue tends to have very limited exploitability, because it's valuable, not-yet well understood, and public exploits are yet to be developed.

Compare to that a similar vulnerability in an older package: chances are that everything about it has been learned and is publicly known. Exploits have become a commodity and are now part of every offensive security distro on the planet. If you run that vulnerable version, there's a real risk that a non-targeted campaign will randomly bite you.

maerF0x017 days ago

> valuable, not-yet well understood, and public exploits

Except in the scenario that is this exact case: Supply chain attacks that are developed with the exploit in mind.

Hackbraten17 days ago

I agree in principle. But even if the backdoor is deliberate (as is the case here), there’s limited risk for the average person. Nobody in their right mind is going to attack Jane Doe and risk burning their multi-million dollar exploit chain.

For an old vulnerability, however, any unpatched system is a target. So the individual risk for the average unpatched system is still orders of magnitude higher than in the former scenario.

denimnerd4217 days ago

and when you do get a security issue and you're using a 10 year old version the upgrade is going to be really really difficult vs incremental upgrades when they are available. or are you going to fork and assume responsibility for that library code too?

thegrim00016 days ago

This drove me crazy at previous companies where our build system dependencies were specified with wildcards so they would just auto pull in the latest version whenever you built the project. Not only are there security issues with that, as seen here, but it destroys your ability to have deterministic builds; every time you build the project it might be building against a different set of dependencies. You lose the ability to even compare builds against each other, because even though the builds are for the same exact project code, the dependency binaries might be different, and so the two builds could run differently.

MySweetHubert16 days ago

The 2017 WannaCry ransomware attack would be a good counter example, the virus spread even though it was already fixed in an update from MS a bit more than a month before.

Vicinity963517 days ago

I'm kinda the opposite. Way too many times I've seen "upgrades" actively remove things I liked and add things I hate. I hold off on letting mobile apps update because they almost always get worse, not better.

hinkley16 days ago

I think it was Ted Neward who argued that libraries should come with a core and ancillary packages. Only the stuff really necessary and broadly popular goes into the base library, and all of the low use features should go into one or more ancillary libraries.

I still think this is the way to go, but it does move some of the problem around in that you have to pick good cleave lines such that people aren’t forced to pull 5 libraries in for 5 features they need. You want one software domain to use two or three and another to use an overlapping set of three.

nilsherzig17 days ago

Wouldn't that just result in exploits written for old versions? A successful exploit for something that everyone is running might be worse, than a backdoor on blending edge systems.

Everyone being on different versions results in something like a moving target

paulmd17 days ago

well, it's the bazaar vs the cathedral, isn't it? bazaar moves a lot faster. Everyone likes that part, except when it breaks things, and when they have to chase an upstream that's constantly churning, etc. but most people don't consider that a cathedral itself might have some engineering merit too. cathedrals are beautiful and polished and stable.

I highly encourage people to try freeBSD sometime. Give ports a try (although the modern sense is that poudrie is better even if you want custom-built packages). See how nicely everything works. All the system options you need go into rc.conf (almost uniformly). Everything is documented and you can basically operate the system out of the FreeBSD Handbook documentation (it's not at all comparable to the "how to use a window or a menu" level intro stuff the linux provides). You can't do that when everything is furiously churning every release. everything just works, everything is just documented, it's an experience when you're coming from linux.

and that forum post from 2007 on how to tweak a service script is probably still valid, because BSD hasn't had 3 different init systems over that timespan etc.

just like "engineering is knowing how to build a bridge that barely doesn't fall over", engineering here is knowing what not to churn, and fitting your own work and functionality extensions into the existing patterns etc. like it doesn't have to be even "don't make a bigger change than you have to", you just have to present a stable userland and stable kernel interface and stable init/services interface. the fact that linux doesn't present a stable kernel interface is actually fairly sketchy/poor engineering, it doesn't have to be that way, a large subset of kernel interfaces probably should be stable.

nickm1216 days ago

I don't believe this will result in conservatism around upgrading nor that it would be good if it did. The vast, vast majority of security vulnerabilities are due to regular bugs and once the details are known, they can be exploited. Not patching leaves you open to these exploits.

Supply chain attacks are a real threat too, but being conservative about upgrading to improve your security posture is like saying "I'm worried someone with the key to my house might rob me, so I'm going to remove the lock from my door."

cryptonector17 days ago

That's a double-edged sword. What happens when you need to upgrade in order to get vulnerability fixes?

sebstefan17 days ago

Maybe one of the outcomes of this could be a culture change in FOSS towards systematically banning rude consumers in Github issues, or, just in general, a heightened community awareness making us coming down on them way harder when we see it happen.

Aurornis17 days ago

The attackers will leverage any culture that helps them accomplish their goals.

If being rude and pushy doesn’t work, the next round will be kind and helpful. Don’t read too much into the cultural techniques used, because the cultural techniques will mirror the culture at the time.

coldpie17 days ago

Even if the security outcome is the same, I would still count people being kind and helpful online instead of rude as an improvement.

saghm17 days ago

As always, there's an xkcd for that

cryptonector17 days ago

That's amazing.

tamimio17 days ago

Spot on. The counter should be sound regardless of any social or cultural context, a process where being polite or rude, pushy or not is irrelevant.

advaith0817 days ago

Agree. I think a more core issue here is that only 1 person needed to be convinced in order to push malware into xz

apantel17 days ago

The Jia Tan character was never rude. If you make rudeness the thing that throws a red flag, then ‘nice’ fake accounts will bubble up to do the pressuring.

genter17 days ago

The assumption is that the group behind this attack had sock puppets that were rude to Lasse Collin, to wear him down, and then Jia Tan swept in as the savior.

patmorgan2317 days ago

Jia Tan wasn't rude, but the original maintainer Laser Collin probably wouldn't have been as burned out and willing to give responsibility to them if the community wasn't as rude and demanding of someone doing free work for them.

I think we need to start paying more of these open source maintainers and have some staff/volunteers that can help them manage their git hub issue volume.

orthecreedence17 days ago

The article covers that those rude accounts may have been sybils of the attacker to create pressure. It's effectively good cop/bad cop for open source.

berniedurfee16 days ago

There was definitely good cop/bad cop going on. That’s a really powerful psychological tool.

sebstefan17 days ago

Pressuring the maintainer is already rude in itself and being polite about it won't help them

If they want things done quickly they can do it themselves

ant6n17 days ago

> If they want things done quickly they can do it themselves

I mean they kind of did. And that was the problem.

publius_0xf317 days ago

I want to caution against taking a good thing too far.

There's a certain kind of talented person who is all too conscious of their abilities and is arrogant, irascible, and demanding as a result. Linus Torvalds, Steve Jobs, Casey Muratori come to mind. Much as we might want these characters to be kinder, their irascibility is inseparable from their more admirable qualities.

Sometimes good things, even the best things, are made by difficult people, and we would lose a lot by making a community that alienates them.

djmips17 days ago

That's a tough one - It's hard to fully disagree but in my experience you can have all the benefits without the poison. Accepting the poison just because of the benefits is kind of just giving up. I don't feel like the your hypothesis that the two are irrevocably linked holds up under examination.

Tainnor17 days ago

Linus Torvalds is apparently trying to do better (although I haven't followed up with the progress), but more importantly, while he might be (have been) unnecessarily rude and aggressive, he's not entitled (as far as I know). I don't think he would jump into an issue tracker of some project he doesn't maintain and demand that certain changes be made.

GreenWatermelon16 days ago

After watching a recent talk with Linus Torvalds[0], it seems that he's become more soft spoken.

[0] clip about the Nvidia "incident"

RyanCavanaugh17 days ago

There are plenty of hyper-competent technical people in the field who are also kind and patient. Being smart doesn't turn someone into a jerk.

ok12345617 days ago

People have been bullied out of 'nice' communities. See the 'Actix' debacle in Rust.

dralley16 days ago

While I don't condone some of the treatment he received, that situation was extremely different.

A user reported a safety issue, the maintainer said it was safe. Then it was proven that it was in fact unsafe, and the maintainer justified it with performance. Then a PR was filed which was safe and did not regress performance, and the maintainer rejected it with "this patch is boring"

The behavior of both sides was deeply unacceptable. If someone identifies a legitimate issue and files a PR to fix it, don't insult them by calling the patch "boring" and don't reject it solely on that basis.

mzs17 days ago

That was mostly redditors though. Reddit is not a nice community.

account429 days ago

Most "nice" communities aren't all that nice if they consider you to be part of the out group.

infamouscow16 days ago

Redditors on r/rust are ostensible the same as saying Rust programmers.

Tainnor17 days ago

I don't want to excuse rudeness or a sense of entitlement. But I think we can still understand where it comes from. A lot of these people probably work on crappy codebases where "let's just add a random dependency without any vetting" was the norm, they might have to deal with production issues etc. There's probably a systemic issue behind it, that our industry relies too much on unpaid labour and is usually not willing to contribute back.[0]

[0] Funnily enough, just a week or two ago, I fixed an issue in an OS project that we introduced at work. It was an easy frontend fix even for someone like me who doesn't do frontend and barely knows how to spell Vue. And more importantly, in the issue description somebody already wrote exactly what causes the bug and what would need to change - the only thing left was finding the place where to make the (one-line) change. Somehow that issue had been open for 2 years but nobody of the several people who complained (nor the maintainer) had bothered to fix it. After I made a PR, it was merged within a day.

GoblinSlayer17 days ago

Just don't do anything crazy. There are legitimately crazy people asking for crazy things, not necessarily backdoors.

Vicinity963517 days ago

Being rude is... unimportant. A lot of people think being passive aggressive is being polite when it's actually being rude + deceitful. There's nothing wrong with being direct, which some mistake for rude. I find it refreshing.

mseepgood17 days ago

Never allow yourself to be bullied or pressured into action. As a maintainer, the more a contributor or user nags, the less likely I am to oblige.

pixl9717 days ago

The issue here is the attackers will quickly move away from an individual attacking you to the group attacking you. The person writing the infected code will never be a jerk to you at all. You'll just suddenly see a huge portion of your mailing list move against you ever so slightly.

We've complained about bots in social media for a long time, but how many people in open source discussions are shady manipulative entities?

simultsop16 days ago

This is so true, distrusting the guys never being jerk to you while others do is the hardest thing ever. Intentions will never be public :/

galleywest20017 days ago

These days you can even have these emails automatically taken in by an LLM and have the LLM argue with the maintainer for you, no humans needed!

snerbles17 days ago

Maintainers will need LLM sockpuppets of their own to automatically answer these automatic emails.

kenjackson17 days ago

But in this case he was getting hit by both someone willing to help and then multiple people complaining that things were taking too long. And when you yourself feel like things are taking too long then you’re probably more susceptible to all this.

resource_waste17 days ago

That sounds nice.

I did an engineering/program manager role for 8 years and people pretty much always did what I asked if I showed up at their desk or bothered their boss.

"Squeaky wheel gets the grease?"

But I too like to think that I prioritize my children on merit rather than fuss level. For some reason they continue to cry despite me claiming I don't react to it.

kjellsbells17 days ago

True, but a determined adversary like JiaTan/Jugar has an ace up their sleeve: they are good enough, and patient enough, to be able to fork the base project, spend a year or two making it better than the original (releasing the head of steam built up from legitimate requests that the old, overworked maintainer never got too, building goodwill in the process) and then convincing the distros to pick up their fork instead of the older original. At which point it really is game over.

cesarb17 days ago

> and then convincing the distros to pick up their fork instead of the older original.

Given the current situation, I'm slightly worried about Fedora's planned move to zlib-ng instead of zlib in the next release (

lukaslalinsky17 days ago

The social side of this is really haunting me over the last days. It's surprisingly easy to pressure people to giving up control. I've been there myself. I can't even imagine how devastating this must be to the original author of XZ, especially if he is dealing with other personal issues as well. I hope at least this will serve a strong example to other open source people, to never allow others to pressure them into something they are not comfortable with.

nathell17 days ago

It makes Rich Hickey’s „Open Source Is Not About You” [0] particularly poignant.

As a hobbyist developer/maintainer of open source projects, I strive to remember that this is my gift to the world, and it comes with no strings attached. If people have any expectations about the software, it’s for them to manage; if they depend on it somehow, it’s their responsibility to ensure timely resolution of issues. None of this translates to obligations on my part, unless I explicitly make promises.

I empathize with Lasse having been slowed down by mental issues. I have, too. And we need to take good care of ourselves, and proactively prevent the burden of maintainership from exacerbating those issues.


pixl9717 days ago

>having been slowed down by mental issues

Anyone and everyone in the OSS world should be concerned about this too. You have nation state level actors out there with massive amounts of information on you. How much information have you leaked to data brokers? These groups will know how much debt you're in. The status of your relationships. Your health conditions and medications? It would not take much on their part to make your life worse and increase your stress levels. Just imagine things like fake calls from your bank saying that debt of yours has been put in collections.

berniedurfee16 days ago

Not just nation state actors. All that data is available to anyone with a credit card from legit data dealers.

raxxorraxor17 days ago

This is why I find some disclaimers in some open source projects quite superfiscial, that the software is provided as is without any warranty. Of course it is, this should be the obvious default.

If there is a law that would entitle a user to more, it is a bug in legislation that needs urgent fixing.

somat17 days ago

I see this as sort of the pivot on how people choose an open source license. When you feel like you are building the thing for others use a gplish license, it has all sorts of clauses around getting everyone to play nice. Building the thing for yourself however, I think the bsd style license makes more sense. you don't really care what anyone else is doing with it, you don't want to form a community. however, because it is trivial to share source code, you do so.

lr197017 days ago

Look how brilliantly they selected their target project:

(1) xz and the lib are widely used in the wild including linux kernel, systemd, openSSH; (2) single maintainer, low rate of maintenance; (3) the original maintainer has other problems in his life distracting them from paying closer attention to the project.

I am wondering how many other OSS projects look similar and can be targeted in similar ways?

baq17 days ago

I'm thinking 95% of home automation which is full of obscure devices and half baked solutions which get patched up by enthusiasts and promptly forgotten about.

Controlling someone's lights is probably less important than Debian's build fleet but it's a scary proposition for the impacted individual who happens to use one of those long tail home assistant integrations or whatever.

davedx17 days ago

A lot of home automation controls EV charging these days too. Imagine an attack that syncs a country’s EV fleet to charge in a minute where demand is at a peak. You could cause some damage at the switchgear I bet if not worse

orthecreedence17 days ago

A takeaway for me is to be extremely tight with personal information on the internet. People will use this to craft a situation to fool you.

Are you married? Have a house? Pets? Children? Sick parent? Gay? Trans? Mental health issues? Disabled? All of this can be used against you. Be careful where and how you share stuff like this. I know it's not "cool" to be mysterious online anymore, but it creates a much larger attack surface. People can still engage with groups around these things, but better to do it with various personas than to have one trackable identity with everything attached to it.

lenerdenator17 days ago


We're in a tech slowdown right now. There are people who got used to a certain lifestyle who now have "seeking work" on their LinkedIn profiles, and who have property taxes in arrears that are listed in county newspapers-of-record. If you're an intelligence operative in the Silicon Valley area, these guys should be easy pickings. An envelope full of cash to make some financial problems go away in exchange for a few commits on the FOSS projects they contribute to or maintain.

apantel17 days ago

Yes it seems a lot like a case of a predator picking off a weak and sick individual.

tommiegannert17 days ago

The Jigar Kumar nudges are so incredibly rude. I would have banned the account, but perhaps they contributed something positive as well that isn't mentioned.

I wonder if it would be possible to crowdsource FOSS mailing list moderation.

goku1217 days ago

There is a good chance that everyone in that thread except the original maintainer is in on the act. It's likely that all those accounts are managed by a single person or group. Targeting just one account for rudeness isn't going to help, if that's true.

imglorp17 days ago

The mechanism employed here seems like the good cop, bad cop interrogation/negotiation technique. There is the one person who has taken care to show cultural and mission alignment. Then there are several misaligned actors applying pressure which the first person can relieve.

How to identify and defuse:

cduzz17 days ago

Reminds me of the "no soap radio" joke. Joke being euphemism for collective gas lighting, but typically a "joke" played by kids on each other.

Play is just preparing for the same game but when stakes are higher?

lukaslalinsky17 days ago

It does help on the social/psychological side. If you, as an open source project maintainer, have a policy that such rudeness is not acceptable, you are much less likely to become a successful victim of a social attack like this.

michaelt17 days ago
sigmar17 days ago
r00fus16 days ago

The act relies on there being an extreme reluctance to ban. Once the banhammer has been used, the act kind of falls apart. Of course, difference pressure campaigns can then be brought to bear.

We live in an adversarial environment, time to stop playing naively nice. Ideally it isn't the maintainer that has to do all this work.

TheCondor17 days ago

The xz list traffic was remarkably low. More than a few times over the years, I thought it broke or I was unsubscribed.

Messages like Jigar’s are kind of par for the course.

jeltz17 days ago

I think that is intentional and that the goal would have been achieved even if Jigar (who probably is the same guy as Jia) had been banned.

unethical_ban17 days ago

It seems from the reading of this article that jigar is in on the scam. That said, I agree.

coldpie17 days ago

> I would have banned the account

Yeah, same. We should be much more willing to kick jerks out of our work spaces. The work is hard enough as it is without also being shit on while you do it.

delfinom17 days ago

Yea people are too accepting of allowing asshats like the Jigar messages.

Simple ban and get the fuck out. Too often I've dealt with people trying to rationalize it as much as "o its just cultural, they don't understand". No, get the fuck out.

But hey I'm a NYer and telling people to fuck off is a past time.

nindalf17 days ago

Jigar was the same person/group as Jia. They were the bad cop and Jia was the good cop. Banning wouldn't have changed anything. Even if Jigar had been banned, the maintainer would still have appreciated the good cop's helpful contributions in contrast to the unhelpful bad cop. Jia would have become a maintainer anyway.

soraminazuki17 days ago

Not surprising, unfortunately. You'd think malicious actors would be nice to people they're trying to deceive. But after watching a few Kitboga videos, I learned that they more often yell, abuse, and swear at their victims instead.

pixl9717 days ago

Being nice gives people time to think.

Being mean is stressful and stops your brain from working properly. If someone doesn't allow you to be abusive, then they are not a mark. Predators look for prey that falls into certain patterns.

npteljes17 days ago

>I wonder if it would be possible to crowdsource FOSS mailing list moderation.

I think this could be a genuine use of an AI: to go through all of the shit, and have it summarized in a fashion that the user wants: distant and objective, friendly, etc. It could provide an assessment on the general tone, aggregate the differently phrased requests, many things like that.

Crowdsourcing would works best with the reddit / hacker news model I feel, where discussion happens in tree styled threads, and users can react to messages in ways that are not text, but something meta, like a vote or a reaction indicating tone.

Both of these have significant downsides, but significant upsides too. People pick the mailing list in a similar way.

johnny2217 days ago

A big problem is that people allow this sort of thing as part of the culture. I've followed the Fedora and PHP development mailing lists a few different times over the years ans this sort of thing was tolerated across the board. It doesn't matter if you crowdsource the moderation if nobody thinks the behavior is bad in the first place.

Trying to do something about it was called censorship.

npteljes17 days ago
lenerdenator17 days ago

I feel for Lasse.

It's time for more of the big vendors who use these projects in their offerings to step up and give people running these small projects more resources and structure. $20k to have maintainers for each project actually meet twice a year at a conference is chump change for the biggest vendors, especially when compared against the cost of the audits they'll now be doing on everything Jia Tan and Co. touched.

cryptonector17 days ago

As an OSS maintainer, $20k wouldn't help me enough unless I was retired. The issue is not money (or not just money), but time. If a maintainer has a full-time job, they may not have time, and developers/maintainers tend to have full-time jobs, so...

Now maybe one could build a career out of OSS maintainerships, with work/time funded by lots of donations much smaller than a salary but amounting to a salary.

lenerdenator17 days ago

I was thinking more of a fix to the issue of "who the hell's maintaining this package our distro/service/whatever is based on" than a way to make money. The bigger projects (like the kernel) and vendors (MS, IBM/Red Hat, Canonical, Google, etc.) all have a vested interest in knowing the actual identity and basic personalities of people who maintain the important packages. If maintainers avail themselves for a weekend at a conference twice a year (or maybe even a lighter commitment like a few short meetings with a manager) they get some resources for their efforts. The flip side of this, of course, is that these organizations will prefer to include packages from maintainers who agree to this arrangement over those who don't.

Furthermore, these organizations are in a place to put experienced, trustworthy contributors on projects that need maintainers if need be. If Lasse had been able to go to, idk, the Linux Foundation and say, "Listen, I'm getting burnt out, got anyone?" and they said "Sure, we've got this contributor with an established record who would love to help maintain your project", none of this is happening right now.

oefrha17 days ago

I’ve given semi-popular projects that I no longer had the bandwidth to maintain to random people who bothered to email, no pressuring needed. While those projects are probably four to five magnitudes less important than xz, still thousands of people would be affected if the random dude who emailed was malicious. What should I have done? Let the projects languish? Guess I’ll still take the chance in the future.

patmorgan2317 days ago

If it's open source they can just fork it, and if you're no longer maintain yours you can put a link over to their fork. (Or any other active forks). It's still on the user to vet new forms.

account429 days ago

> What should I have done? Let the projects languish?

Yes, if you can't find a successor you trust then let someone fork the project and build trust from 0 rather than transferring trust others' trust in you by handing over the project. This doesn't just apply to security concerns btw. - plenty of other ways in which a new maintainer might end up making the project worse (intentionally or through incompetence) compared to it not receiving any updates.

01HNNWZ0MV43FF17 days ago

I guess all you can do is not give the brand away.

Put a link saying "Hey this guy forked my project, I won't maintain it anymore, he may add malware, review and use at your own risk"

HPsquared17 days ago

I'm reminded of the short story "The Strange Case of Mr Pelham", in which a man is stalked and eventually replaced by a doppelganger.

nebulous117 days ago

In "Ghost in the Wires" Kevin Mitnik details one of the ways he obtained information was via a law enforcement receptionist* who he managed to trick into believing he was law enforcement over the phone. He obtained information this way multiple times over multiple years, and fostered a phone based friendship with this woman. He seemed to have no qualms in doing this.

He was also turned on by multiple people who he considered close friends. In the book it did not seem that he had considered that it might not be a "them" problem.

*my details may be off here, I read it some time ago

mirekrusin17 days ago

It's bizzare enough as it is to start asking questions to confirm that "mental issue" had natural cause.

couchand17 days ago

Your experiences may differ, but I'd say pretty much anyone who lived through the past few years has reason enough to pay careful attention to their mental health.

NarcissistDev17 days ago

Thank the lord Lasse wasn’t maintaining the nuclear codes.

In another thought, I hope the nukes aren’t on a rolling Debian distro.

jhoechtl17 days ago

> merges hidden backdoor binary code well hidden inside some binary test input files. [...] Many of the files have been created by hand with a hex editor, thus there is no better "source code" than the files themselves.

So much for the folks advocating for binary (driver) blobs in OSS t support otherwise unsupported hardware.

It's either in source form and reproducable or it's not there.

mseepgood17 days ago

Not just for hardware support:

cryptonector17 days ago


pixl9717 days ago

>It's either in source form and reproducable or it's not there.

Wanna know how I know you haven't read into the discussion much?

There are a whole lot of binary test cases in software. Especially when you're dealing with things like file formats and test cases that should specifically fail on bad data of particular types.

cryptonector17 days ago

GP is talking about executable blobs (drivers) more than anything. Yes, binary protocols will lead to binary test blobs, so what.

pixl9716 days ago

The attack was embedded in a binary test blob, or did you just not happen to read anything about the xy attack?

cryptonector16 days ago

You can't avoid having to have binary blobs of data. And again, GP was talking about closed-source drivers, not specifically the xz attack.

TacticalCoder17 days ago

> There are a whole lot of binary test cases in software.

That's not how I read GP's point. If even binary blobs in test cases are a place where backdoors are, now as a matter of fact, hidden then, certainly, among the folks advocating for binary drivers in FOSS, there are some who are already --or planning to-- add backdoors there.

Binary blobs are all terrible, terrible, terrible ideas.

Builds should be 100% reproducible from source, bit for bit. At this point it's not open up for discussion anymore.

pixl9717 days ago

Then you figure out how to build a 'source' test case of a bad zip, or bad jpg, or word document or whatever else exists out there. Also figure out how to test that your bit4bit perfect binary isn't doing the wrong damned thing in your environment with actual real data.

Hackbraten17 days ago

In cryptography, there's the concept of a nothing-up-my-sleeve number. [1]

Instead of obscure constants, you use known constants, or at least simple methods to derive your constants.

You can do the same thing to come up with your test cases. Bad zip? Construct a good zip of 10 files, each containing the first 10,000 prime numbers. Then corrupt the zip by seeking to position (100/pi) and write a thousand zeroes there.

Bad JPEG? Use Imagemagick to render the first 1000 prime numbers as text into a JPEG file, then apply a simple nothing-up-my-sleeve corruption operation.

There are still cases where this approach isn't going to work: that new icon, helpfully proposed by a contributor, meant to be used in production, might contain malicious code, steganographically embedded. I think there's little you can do to prevent that.


Eduard15 days ago

> It's either in source form and reproducable or it's not there.

Forbidding binary data in source repositories is neither practical nor solving the issue.

Binary code can be hidden steganograhically in e. g. image files or text files.

tredre317 days ago

Are you running linux-libre?

jvanderbot17 days ago

> It's also good to keep in mind that this is an unpaid hobby project.

That's the root cause. At some point a corp/gov consortium needs to adopt key projects and hire out the maintainers and give them real power and flexibility, perhaps similar to the way a nation might nationalize key infrastructure.

But this is against the core ethos at some level. Freedom and safety can be antagonistic.

tamimio17 days ago

You are implying that governments are more technically competent and more trustworthy than open source communities..

mttpgn17 days ago

Many open source projects often already do receive US government funding, mostly through an onerous grant-application process. Nationalizing American open source projects could make them operate more like European open source where their EU funding is open and clear. The detrimental trade-off, however, is that the American agencies most capable to support and contribute directly to infrastructure security have burned away all trust from the rest of the world. Direct contributions directly from those USG agencies would reduce global trust in those projects even worse.

jvanderbot17 days ago

I said nothing of the sort.

I'm implying they are richer.

none_to_remain17 days ago

Avoid compromise with one simple trick: surrender to the attackers

jvanderbot16 days ago

I don't understand how "Accept public money to work full time on key software" is surrender, but I think everyone misunderstood what I said, which usually means I didn't say what I meant.

maerF0x017 days ago

> gov consortium

Personally I wouldnt trust a govt to not backdoor everything.

jvanderbot17 days ago

A consortium is a great way to get money and power into those maintainers. Never said they should take the power from them or provide code. I think people are hearing their own mind here, not mine.

deathanatos17 days ago

> Evan Boehs observes that Jigar Kumar and Dennis Ens both had nameNNN@mailhost email addresses

This is the second time I've read this "observation", but this observation is just wrong? Jigar's email is "${name}${number}@${host}", yes, but Dennis's is just "${name}@${host}" — there's not a suffixed number. (There's a 3, but it's just a "leetcode" substitution for the E, i.e., it's semantically a letter.)

(They could still both be sockpuppets, of course. This doesn't prove or disprove anything. But … let's check our facts?)

__float17 days ago

Where are the email addresses visible? I've also seen this a few times, but never the actual addresses.

matsur17 days ago

eg "Hans Jansen" is <>

mmcwilliams16 days ago

I'm maybe naive in assuming that there is some kind of investigation going on that isn't playing out in public, but I would assume that years of emails going through Microsoft servers might make the identities of the cohorts in this attack difficult to hide?

rainbowzootsuit16 days ago

When making sockpuppet email accounts use a plausible birth year as your numeric extension.

deathanatos16 days ago

In the OP, many of the links (e.g., "first, innocuous patch") lead to From there, click the button with the name that appears after "Reply via email to", and it will open your email client, with the To: filled in with the email of the person.

glitchcrab17 days ago

I couldn't spot email addresses directly in plaintext for those who weren't submitting patches (e.g. Jigar), however if you look at one of the links to his (?) responses then there's a mailto link with the text 'Reply via email'

jbdigriz99017 days ago

Joe Cooper's take on pressuring project maintainers:

somewhat ironic, but I'd say effective.

Longlius17 days ago

I don't even think it's necessarily moderation so much as maintaining these high-traffic projects is now akin to a full-time job minus the pay.

At a certain point, companies need to step up and provide funding or engineering work or they should just keep expecting to get owned.

Vegenoid17 days ago

If there is a larger shift to companies paying for the software they rely on that is currently free, it's not going to be companies paying open-source maintainers, it's going to be companies paying other companies that they can sign contracts with and pass legal responsibility to.

nmz17 days ago

Why would they when they can just... not?

jrochkind117 days ago

This seems very difficult to defend against. What is a project with a single burnt-out committer to do?

rsc17 days ago

lcamtuf's two posts argue that this may simply not be an open-source maintainer's job to defend against. ("The maintainers of can’t be the only thing that stands between your critical infrastructure and Russian or Chinese intelligence services. Spies are stopped by spies.")

That doesn't mean we shouldn't try to help burnt out committers, but the problem seems very hard. As lcamtuf also says, many things don't need maintenance, and just paying people doesn't address what happens when they just don't want to do it anymore. In an alternate universe with different leadership, an organization like the FSF might use donated funds to pay a maintenance staff and an open-source maintainer might be able to lean on them. Of course, that still doesn't address the problem of Jia Tan getting a job with this organization.

intunderflow17 days ago

Why the assumption this is a Russian or Chinese intelligence service? Western governments aren't above this sort of conduct:

cb32117 days ago

Why are people assuming it's any intelligence service/state actor? With cryptocurrency valuations, it would seem like remote rooting gajillions of machines would be highly incentivized for a private person/collective. Not to mention other financial incentives. Our digital infrastructure secures enormous value much of which can be pilfered anonymously.

I admit, the op has a "professional/polished vibe" to me as well, but we seem to know very little except for what work time/zones were preferred by the possibly collective/possibly singular human(s) behind the Jia Tan identity. Does anyone have slick linguistic tools to assess if the writer is a single author? Maybe an opportunity to show off.. It's sort of how they caught Ted Kaczynski.

It also absolutely makes sense to think of all the state actors (I agree including as you say the US/UK) as part of the ongoing threat model. If the KGB/Ministry of State Security/NSA/MI6 were not doing this before then they surely might in the future. Maybe with more gusto/funding now! They all seem to have an "information dominance at all costs" mentality, at least as agency collectives, whatever individuals inside think.

maerF0x017 days ago
rsc16 days ago

I don't think there's necessarily an assumption that it was Russia or China this time (the Chinese-sounding name is almost a dead giveaway that it's someone other than China), but the security world does believe quite strongly that it has been Russia (SolarWinds) and China (Juniper) before, so they are the usual examples.

wumeow17 days ago
uluyol17 days ago

There are efforts from industry to try to secure open source, e.g.,

I suspect some variant of this will grow so that some companies, MS/GitHub for example, audit large body of code and vet it for everyone else.

meowface17 days ago

As a burnt out creator of open source projects with thousands of GitHub stars who's received numerous questionable maintainership requests: either very carefully vet people or let it stagnate. I chose the latter and just waited until others forked it, in large part because I didn't want to be responsible for someone hijacking the project to spread malware.

If I had ever received a request from a well-known figure with a longstanding reputation, who's appeared in-person at talks and has verifiable employment, I might've been more receptive. But all the requests I got were from random internet identities that easily could've been fabricated, and in any case had no previous reputation. "Jia Tan" and their other sockpuppets very likely are not their real identities.

clnhlzmn17 days ago

This is not Lasse Collin’s responsibility. What is a burnt out committer supposed to do? Absolutely nothing would be fine. Doing exactly what Lasse Collin did and turn over partial control of the project to an apparently helpful contributor with apparent community support is also perfectly reasonable.

coldpie17 days ago

It's not a perfect solution, but I think Big Companies could have a role to play here. Some kind of tenure/patronage system, where for every $1B a Big Company makes in profit, they employ one critical open source maintainer with a decent salary (like $200k or something). The job would only have two requirements: 1) don't make everyone so mad that everyone on the Internet asks for you to be fired, and 2) name a suitable replacement when you're ready to move on. The replacement would become an employee at Big Company, which means Big Company would need to do whatever vetting they normally do (background checks, real address to send paychecks and taxes, etc).

In this scenario, Jia Tan would not be a suitable replacement, since they don't friggin' exist.

Yes, there's problems with this approach. When money gets involved, incentives can get distorted. It limits the pool of acceptable maintainers to those employable by a Big Company. But I think these are solvable problems, especially if there's a strong culture of maintainer independence. It provides a real improvement over the current situation of putting so much pressure on individuals doing good work for no benefit.

jodrellblank17 days ago

> "It's not a perfect solution"

Is it a solution at all? Say Oracle offer Lasse Collin $200k for maintaining xz but he doesn't want to work for Oracle so he refuses, then what? Amazon offer Lasse $200k but they require fulltime work on other open source packages which he isn't experienced with or interested in, so he refuses, then what? Google employ someone else for $200k but they can't force Lasse Collin to hand over commit rights to xz to Google, or force him to work with a fulltime Google employee pestering with many constant changes trying to justify their job, and they can't force Debian to accept a new Google fork of xz, so then what? And NetFlix, Microsoft, Facebook, Uber, they can't all employ an xz maintainer, xz doesn't need that many people, but if they just employ 'open source maintainers' scattering their attention over all kinds of random projects they have no prior experience with, how would they catch this kind of subtle multi-pronged long-term attack on some low-attention, slow moving, project?

Google already employ a very capable security team who find issues in all kinds of projects and publicise them, they didn't find this one. Is it likely this attack could have made its way into ChromeOS and Android if it wasn't noticed now, or would Google have noticed it?

> "1) don't make everyone so mad that everyone on the Internet asks for you to be fired"

So it's a sinecure position, doing nothing is the safest thing?

> "and 2) name a suitable replacement when you're ready to move on"

How could Lasse Collin have named a more suitable replacement than someone who seemed technically capable, interested in the project, and motivated to work on some of the boring details like the build system and tests and didn't seem to be doing it for the hype of saying "I improved compression by 10%" for their resume? Are they needing to be skilled in hiring and recruitment now?

coldpie17 days ago

I think you've misunderstood my suggestion. I said the job has two responsibilities. No more. You added a bunch of other responsibilities, I'm saying those wouldn't be allowed. It would be in the employment agreement that is purely payment for doing the maintainership tasks they were already doing. It would be a culture expectation that the company not apply pressure on maintainers.

> but if they just employ 'open source maintainers' scattering their attention over all kinds of random projects they have no prior experience with

They would pay the people who are doing the work now. Under this hypothetical, one of the Big Companies would have hired Lasse as the xz maintainer, for example. His job responsibilities are to maintain xz as he had been doing, and identify a successor when he's ready to move on. Nothing else.

> So it's a sinecure position, doing nothing is the safest thing?

No. Not doing the maintenance tasks would make everyone mad, violating one of the two job responsibilities.

> How could Lasse Collin have named a more suitable replacement than someone who seemed technically capable, interested in the project, and motivated to work on [it]

Lasse would suggest Tan as a suitable replacement. Big Company's hiring pipeline would approach Tan and start the hiring process (in person interviews, tax docs, etc etc). At some point they would realize Tan isn't a real person and not hire him. Or, the adversary would have to put up "a body" behind the profile to keep up the act, which is a much higher bar to clear than what actually happened.

jodrellblank17 days ago
sloowm17 days ago

I think the best solution would be governments forcing companies to secure the entire pipeline and setting up a non profit that does this for open source packages. Have security researchers work for a non profit and force companies that use software from some guy in Nebraska to pay into the non profit (could be in the form of labor) to get the code checked and certified.

The guy in Nebraska is still not getting anything but will also not have the stress of becoming one of the main characters/victims in a huge attack.

ta124316 days ago

This is the problem - we have record numbers of computer programmers, having increased exponentially from the 90s, however very few of them want to work just for fun on some library buried deep in the system, most are just out for a quick buck.

Look at the number of people who make meaningful commits to ffmpeg vs the number of people that wrap it in some UI and somehow persuade thousands of people that their solution is amazing, and ffmpeg is a sexy project.

Vicinity963517 days ago

Until we can patch humans, social engineering will always work. Burnt-out comitter or not. Just be vigilant.

NarcissistDev17 days ago

The same as what the ant colonies do when one of their own gets infected by the Ophiocordyceps unilateralis fungus.

INTPenis17 days ago

That's a great question and instinctively I'd say better to halt development than cave to pressure.

2devnull17 days ago

Check the GitHub profile of anybody that commits. Is there a photo of the person? Can you see a commit history and repos that help validate who they seem to be.

In this instance, noticing the people emailing to pressure you have fake looking names that start with adjacent letters and the same domain name.

Be more paranoid.

pixl9717 days ago

> Is there a photo of the person?

Does that even matter these days?

Especially if we're talking nation state level stuff convincing histories are not hard to create to deflect casual observers.

>Be more paranoid.

Most people in OSS just want to write some code to do something, not defend the world against evil.

2devnull16 days ago

“Does it even matter?”

Yes, it would have prevented this attack. It isn’t totally sufficient but it’s quick and easy and would have prevented this attack.

“Most people don’t want …”

I get it. I think the issue is that pushing junk code from malicious contributors into your project causes more hassle in the long run. If you just want to code and make stuff work, you should probably be careful who you pull from. It’s not just for the benefit of others, it’s first and foremost to protect the code base and the time and sanity of other contributors.

pixl9716 days ago

"Sorry, we had to kill open source software because bad people exist" -Microsoft laughing all the way to the bank.

The more paranoid walls you put up the more actual contributors getting into the movement say "eh, screw this, who wants to code anyway".

This isn't just a problems with OSS, this is a fundamental issue the internet as a whole is experiencing and no one has good answers that don't have terrible trade offs of their own.

pabs316 days ago

Only non-paranoid people have a photo of themselves online.

caoilte17 days ago

get the project taken over by a foundation eg the Apache Foundation.

alickz16 days ago

tell people to fork your project and fuck off

dep_b16 days ago

My god, Hans Jansen? You need to be 60 years old to have that name in The Netherlands, it's so stereotypical that it would definitely ring some alarm bells if I saw it.

It's like seeing a "Bill Johnson, real American patriot" account on Twitter: would not believe it at face value.

edg500017 days ago

I wonder, once the attacker gained commit permissions, were they able to rewrite and force push existing commits? In that case rolling back to older commits may not be a solution.

If my speculation is correct then the the exact date on which access was granted must then first be known, after that a trusted backup of the repo from before that date is needed. Ideally Lasse Collin would have a daily backup of the repo.

Although perhaps the entire repo may have to be completely audited at this point.

ajross17 days ago

Force pushes tend to be noticed easily. All it takes is for one external developer to try to pull to see the failure. And it's actually hard to do because you need to comb through the tree to update all the tags that point to the old commits. On top of that it obviously breaks any external references to the commit IDs (e.g. in distro or build configurations), all the way up to cryptographic signatures that might have been made on releases.

I think it's a pretty reasonable assumption that this didn't happen, though it would be nice to see a testimony to that effect from someone trustworthy (e.g. "I restored a xz checkout from a backup taken before 5.6.0 and all the commit IDs match").

skykooler16 days ago

Of course, that's only since the attack was caught early. Since it affected the machines that build packages, a next step could have been, say, to add code to Git to make it ignore certain commit IDs or mask them in some way. Maybe even modify Firefox, Chromium etc to not show those changes on github. With a backdoor like this and enough time undetected, you could control basically everything.

fl730517 days ago

> And it's actually hard to do because you need to comb through the tree to update all the tags that point to the old commits.

Isn't this part just a few pages of code, if that?

I agree that it will be blindingly obvious for the reasons you list.

sloowm17 days ago

The way the hack works is incredibly sophisticated and has specifically sought out how to get past all normal checks. If messing with some commits would be possible this entire rube goldberg hack would not have been set up.

Denvercoder917 days ago

There are trusted copies of historic releases from third-party sources (at least Linux distributions, but there's probably other sources as well), it's pretty easy to check whether the tags in the git repository match those. (This can be done as the tarballs are a superset of the files in the git repository, the other way around doesn't work).

mattxxx17 days ago

A service that measured "credibility" or "activity" of a username/email could be really useful here. At least, it would be a leading indicator that something _might_ be up. In particular the aside here about the email addresses are suspect:

would be useful info for Lasse Collins before taking the pressure campaign seriously.

iso8859-117 days ago

What about just using 'web of trust', for example with GPG? If the user's key is signed by people that met up with the actual person, it would be much harder to make fake identities.

ptx17 days ago

There was an article from 2019 [0] that someone on HN linked recently about how "web of trust is dead", but it seems to concern scalability problems with the keyserver, which resulted in DoS attacks, which made them disable the feature by default. The concept should presumably still be good, assuming the issues specific to the GPG keyserver can be avoided.


carols10cents17 days ago

What would prevent the sock puppet accounts from signing each others' keys?

iso8859-116 days ago

They could do that, but you'd be able to see that nobody/few outside their cluster signed any of their keys.

Let's say they have fake passports and physically appear at key signing parties. Now you're screwed because even your peers (that you thought know how to validate identities using passports) will get fooled.

Read more on GPG's trust levels:

stockhorn17 days ago

I feel like release tarballs shouldnt differ from the repo sources. And if they do, there should be a pipeline which generates and upload the release artifacts....

Can somebody write a script which diffs the release tarballs from the git sources for all debian packages and detects whether there are any differences apart from the files added by autotools :)?

kevindamm17 days ago

Small nit to pick, but in the introductory paragraph it reads "unauthenticated, targeted remote code execution." I recall that there was a special private/public key pair that made this exploit only reproducible by the author (or only possible after re-keying the binary).

I believe this means it was unauthorized, not unauthenticated.

mcpherrinm17 days ago

I think it is unauthenticated from the point of view of SSH’s own authentication. The backdoor has its own credential, but the RCE is accessible if you don’t have an account on the system.

kevindamm17 days ago

That's the basis for my preferring the term relating to authorization. The two terms have distinct and well-defined meanings in the domain. They're both critical aspects of security but for different reasons.

mcpherrinm17 days ago

The distinction between authentication and authorization is important, but only in the context of what’s checking that auth(n/z) is valid.

For something like SSH which has authentication and authorization as features, I would expect to talk about an RCE in that context, and not the backdoor’s auth features.

This backdoor bypasses both authentication (not requiring an account password, authorized key, etc on the target system) as well as authorization (as it doesn’t check a user against any policy for what commands or users can log in).

dist-epoch17 days ago

Remote code execution already implies unauthorized. There is no such thing as authorized remote code execution.

kevindamm17 days ago
gquere17 days ago

There totally is authenticated RCE, for instance a PHP page that contains a RCE but needs a prior authentication to access the resource.

All RCEs are classified in either unauthenticated or authenticated, the former being the worst (or best if you're a researcher/hacker).

rsc17 days ago

"unauthenticated remote code execution" is a fairly standard term for this kind of access.


kevindamm17 days ago

Fairly standard term for a kind of access similar to this, but the distinction is important.

Consider the impact if anybody else, not just this attacker, could have exploited it -- on the other hand, it may have been discovered sooner (had it also not been discovered by accident first).

gregwebs17 days ago

I think this can be made much more difficult by enforcing a policy of open builds for open source. It shouldn't be possible to inject build files from a local machine. All build assets should come from the source repository. Artifacts should come from Github Actions or some other tool that has a clear specification of where all inputs came from. Perhaps Github could play a role in helping to automate any inconveniences here.

dboreham17 days ago

Yes the whole "let's take a mystery meat tarball from a repo that isn't the project repo" seems suspect.

Github+ even has a scheme for signing artifacts such that you have some level of trust they came from inside their Actions system, derived from some git commit. This would allow the benefits of a modular build for a large product like a distro, while preserving a chain of trust in its component parts.

+Not advocating a dependency on Github per se -- the same sort of artifact attestation scheme could be implemented elsewhere.

shp0ngle17 days ago

as I wrote in a different thread, some projects don't have any source control.

From the big ones - 7z, ncurses are both tarballs only.

patmorgan2317 days ago

They need to join us in the 80s and start using source control.

account429 days ago

Yeah lets make the entire open source ecosystem reliant on Microsoft. No thanks.

maclockard17 days ago

I think that trust needs to be 'pushed deeper' than that so to speak. While this would be an improvement, what happens if there is a malicious actor at Github? This may be unlikely, but would be even harder to detect since so much of the pipeline would be proprietary.

Ideally, we would have a mechanism to verify that a given build _matches_ the source for a release. Then it wouldn't matter where it was built, we would be able to independently verify nothing funky happened.

gregwebs17 days ago

Vendor independent build providence is certainly the long-term goal. In the immediate-term moving away from mystery tarballs towards version control gets us a step closer.

One of the best things about Golang is that packages are shared direct via source repositories (Github) rather than a package repository containing mystery tarballs. I understand the appeal of package repositories, but without proper security constraints it's a security disaster waiting to happen.

qerti17 days ago

Wasn’t the payload in a blob in the tests, which is in the source repo? If you were to clone the repo then build from source, you’d have the backdoor, right? Surely distros aren’t using binaries sent by maintainers

jsnell17 days ago

No. The payload was in the checked in test files, but the test files were inert. They were only activated by the tarball having different build files than the repository (or rather, different build files than would be generated by autotools for the repository), which extracted the payload from the test files and injected it into the output binary.

exacube17 days ago

Is the real identity of Jia Tan known, even by Lasse Collin?

I would think a "real identity" should be required by linux distros for all /major/ open source projects/library committers which are included in the distro, so that we can hold folks legally accountable

rsc17 days ago

Open source fundamentally does not work that way. There are many important open source contributors who work pseudonymously.

Google's Know, Prevent, Fix blog post floated the idea of stronger identity for open source in and there was very significant pushback. We learned a lot from that.

The fundamental problem with stronger identity is that spy agencies can create very convincing ones. How are distros going to detect those?

kashyapc17 days ago

While "open source" fundamentally doesn't work that way, the point here is about maintainers, not regular contributors. Identity of new maintainers must be vetted (via in-person meetups and whatever other mechanisms) by other "trusted" maintainers whose identities are "verified".

I realize, it's a hard problem. (And, thanks for the link to the "Know, Prevent, Fix" post.)

PS: FWIW, I "win my bread" by working for a company that "does" open source.

Edit: Some projects I know use in-person GPG key signing, or maintainer summits (Linux kernel), etc. None of them are perfect, but raises the bar for motivated anonymous contributors with malicious intent, wanting to become maintainers.

oefrha17 days ago

I’ve worked with a few very talented pseudonymous developers on the Internet over the years. I can’t think of any way to vet their identities while maintaining their anonymity (well, it’s basically impossible by definition), plus if you’re talking about in-person meetups, traveling from, say, Asia to North America isn’t cheap and there could be visa issues. The distinction between maintainers and non-maintainers isn’t that meaningful because non-maintainers with frequent and high quality contributions will gain a degree of trust anyway. The attack we’re discussing isn’t about someone ramming obviously malicious code through as a maintainer, they passed or could have passed code review.

kashyapc17 days ago

You make excellent points; I agree. Especially, a non-maintainer with a high-quality contribution gaining trust. Many times, (tired) maintainers are forced to "rubber-stamp" and merge such high-quality patches. It could be due to any number of (valid) reasons—a CVE fix, an involved performance fix that will take you weeks to load up on the context, enabling a hardware feature that's under semi-NDA, you just trust their work too well, maintainer fatigue, etc.

What I'm saying is, in context of critical-path software, the identity of maintainers vs non-maintainers matters more. I'm not naively claiming that it'll "solve" the problem at hand, just that it's another layer in defense. For a critical software, you shouldn't be able to simply submit a "patch"[1] such as:

  tests: Add-binary-blob-with-a-subtle-backdoor.xz

  Signed-off-by: "Anonymous Rabbit" <>
Commit it yourself, brazenly push it into Linux distros, and then anonymously sign off into the sunset with no trace. I'm sure you'll agree that there's a world of difference between a deeply entrenched, critical libray and a random user-space application.

It's a messy situation. How much, if at all, "clever tech" can mitigate this human "trust issue" is an open problem for now.


cesarb17 days ago
nrvn17 days ago

I was initially thinking that one of the core non-tech causes of the was the single-person maintenance mode of the xz project.

But you have a point. As an agency you can seed two jiatan's to serve diligently for a couple of years following the strict 2-person code reviews and then still poison the project. On the other hand, if the xz build process was automated and transparent and release artifacts were reproducible and verifiable even in this poor condition of xz-utils as a project it would have been much harder to squeeze in a rogue m4/build-to-host.m4

delfinom17 days ago

My problem with stronger identity is it violates open source licenses.

Source code is provided without warranty and this statement is clear in the license.

Putting an verified identity behind the source code publish is basically starting to twist said said no-warranty. Fuck that.

in3d17 days ago

The blog post clarified it's about maintainers of critical packages, not all contributors. This could be limited to packages with just one or two maintainers, especially newer ones. And they could remain somewhat anonymous, providing their information to trusted third parties only. If some maintainers don’t accept even this, their commits could be put into some special queue that requires additional people to sign off on them before they get accepted downstream. It's not a complete fix, but it should help.

mapmeld17 days ago

What would prevent a known person from accepting a govt payout to sabotage their project, or to merge a plausible-looking patch? Relying on identity just promotes a type of culture of reputation over code review.

tamimio17 days ago

Nope, identities won’t solve it, you can have people coerced, blackmailed, threatened, or simply just a “front” while there’s a whole team of spies in the background. The process should be about what’s being pushed and changed in the code, but I would be lying to say I have a concrete concept how it is possible.

tester45717 days ago

If this was done by a state actor then this policy wouldn't help at all. States have no shortage of identities to fake.

asvitkine17 days ago

How would that even work? Are distros expected to code their own alternative versions of open source libraries where they can't get the maintainers to send their IDs? Or what stops from forged IDs being used?

gquere17 days ago

This will never be accepted by the community.

chubot17 days ago

Something to add to the timeline: when did this avenue of attack become available?

It only happened in the last 10 years apparently.

Why do sshd and xz-utils share an address space?

When was the sshd -> systemd dependency introduced?

When was the systemd -> xz-utils dependency introduced?


To me this ARCHITECTURE issue is actually bigger than the social engineering, the details of the shell script, and the details of the payload.

I believe that for most of the life of xz-utils, it was a "harmless" command line tool.

In the last 10 years, a dependency was silently introduced on some distros, like Debian and Fedora.

Now maintainer Lasse Collin becomes a target of Jia Tan.

If the dependency didn't exist, then I don't think anyone would be bothering Collin.


I asked this same question here, and got some good answers:

Probably around 2015?

So it took ~9 years for attackers to find this avenue, develop an exploit, and create accounts for social engieering?

If so, we should be proactively removing and locking down other dependencies, because it will likely be an effective and simple mitigation.

duped17 days ago

I don't think these questions are that interesting. SSHD shared an address space with xz-utils because xz utils provides a shared library, and that's how dynamic linking works. sshd uses libsystemd on platforms with systemd because systemd is the tool that manages daemons and services like sshd, and libsystemd is the bespoke way for daemons to talk to it (and more importantly, it is already there in the distro - so you're not "adding a million line dependency" so much as linking against a system library from the OS developers that you need).

Linking against libsystemd on Debian is about as suspicious as linking against libsystem on MacOS. It's a userspace library that you can hypothetically avoid, but you shouldn't.

As for why systemd links against xz, I don't know, and it's a bit surprising that an init system needs compression utils but not particularly surprising given the kitchen sink architecture of systemd.

cesarb17 days ago

> As for why systemd links against xz, I don't know, and it's a bit surprising that an init system needs compression utils

It's for the journal. It can be optionally compressed with zlib, lzma, or zstd. That library had not only the sd_notify function which sshd needed, but also several functions to manipulate the journal.

chubot17 days ago

and that's how dynamic linking works -- really ignorant comment

Read the thread for some quotes on process separation and the Unix philosophy.

There are mechanisms other than dynamic linking -- this is precisely the question.

Also, Unix supported remote logins BEFORE dynamic linking existed.


What about sshd didn't work prior to 2015?

Was the dependency worth it?

not particularly surprising given the kitchen sink architecture of systemd

That's exactly the point -- does systemd need a kitchen sink architecture?


The questions are interesting because they likely lead to simple and effective mitigations.

They are interesting because critical dependencies on poorly maintained projects may cause nation states to attack single maintainers with social engineering.

Solutions like "let's create a Big tech funded consortium for security" already exist (Linux foundation threw some money at bash in 2014 after ShellShock).

That can be part of the solution, but I doubt it's the most effective one.

duped17 days ago

I don't think it's acceptable to create a subprocess for what's effectively a library function call because it comes from a dependency.

The problem is the design of rtld and the dynamic linking model, where one shared library can detect and hijack the function calls of another by using the auditing features of rtld. Hardened environments already forbid LD_PRELOAD for injection attacks like this, but miss audit hooks.

My point is that just saying we should use the Unix process model as the defense for supply chain attacks is like using a hammer to fix a problem that needs a scalpel.

> What about sshd didn't work prior to 2015?

systemd notifications, from what it sounds like.

chubot15 days ago
JeremyNT17 days ago

It's certainly a reasonable question to ask in this specific case. In hindsight Debian and Red Hat both bet badly when patching OpenSSH in a way that introduced the possibility of this specific supply chain attack.

> If so, we should be proactively removing and locking down other dependencies, because it will likely be an effective and simple mitigation.

I think this has always been important, and it remains so, but incidents like this really drive the point home. For any piece of software that has such a huge attack surface as ssh does, the stakes are even higher, and so the idea of introducing extra dependencies here should be approached with extreme caution indeed.

account429 days ago

> It's certainly a reasonable question to ask in this specific case. In hindsight Debian and Red Hat both bet badly when patching OpenSSH in a way that introduced the possibility of this specific supply chain attack.

Notably, Debian bet badly again. They already had this mistake pointed out to them very publicly with the OpenSSL random generator fiasco. Yet they chose to continue applying patches that are not accepted upstream while evidently not understanding the rammifications. Why? Shouldn't there have been a policy change in the Debian project to prevent this from happening again?

chubot17 days ago

Yup, "trusted computing base" is classic concept that we've forgotten

Or we pay lip service to, but don't use in practice

sloowm17 days ago

Another point relevant on the timeline is when downstream starts using binaries instead of source.

I think people are flying past that important piece of the hack. Without that this would not have been possible. If there is a trusted source in the middle building the binaries instead of the single maintainer and the hacker this attack becomes extremely hard to slip by people.

testplzignore17 days ago

I'm not familiar with how distros get the source code for upstream dependencies. I'm trying to understand what Andres meant when he said this:

> One portion of the backdoor is solely in the distributed tarballs

Is it that the tarball created and signed by Jia had the backdoor, but this backdoor wasn't present in the repo on github? And the Debian (or any distro) maintainers use the source code from tarball without comparing against what is in the public github repo? And how does that tarball get to Debian?

Hackbraten17 days ago


The threat actor had signed and uploaded the compromised source tarball to GitHub as a release artifact. They then applied for an NMU (non-maintainer upload) with Debian, which got accepted, and that's how the tarball ended up on Debian's infrastructure.

sloowm17 days ago

Thanks for the extra explanation. I guess this is harder to protect against than I thought and it's more that some distro's got somewhat lucky than debian and fedora doing something that is out of the ordinary.

ajoberstar16 days ago

That's not what happened. Downstream was building from source, that source just had malicious code in it.

One part was binary, the test file (pretty common), but checked into the repo. One part was in the build config/script, but was in the source tarball and not in the repo.

Denvercoder917 days ago

> Another point relevant on the timeline is when downstream starts using binaries instead of source.

No downstream was using binaries instead of source. Debian and Fedora rebuild everything from source, they don't use the binaries supplied by the maintainer. The backdoor was inserted into the build system.

vb-844817 days ago

I wonder if netflix will make a movie from this story, if you read the timeline it really sounds like a well written thriller.

publius_0xf317 days ago

It does, but has there ever been a movie that successfully portrayed a compelling drama that takes place entirely on a computer monitor? It's hard to even imagine. It's why I think the novel is still relevant in our age because all the great stories that unfold on a screen can't be acted out on a sound stage.

bckygldstn17 days ago

Searching [0] gets you halfway there: its about a compelling drama which takes place mostly in real life, but is portrayed entirely on a computer monitor.


vb-844816 days ago

I liked "How to Sell Drugs Online (Fast)", first season.

Generally speaking, you can use the xz story as a background for every type of movie set in the present, an eg.: think about the God's Eye story from the Fast & Furious series. Theoretically, the xz rce can give you more or less the same power God's Eys gives you in the film.

in3d17 days ago

It’s not compelling enough unless we find out who was behind it, which is probably unlikely.

vb-844816 days ago

Well, the identity of who's behind it can be left to the imagination of the authors.

I think it's reasonable to think that behind this attack there is a well organized intelligence agency of a big country, so the author can choose the one that they likes more.

Or, even better, delay the issue to the season 2 :D

dekhn17 days ago

Why do I feel like this set of posts by Russ about supply chain security will end up with a proposal/concrete first implementation of a supply-chain-verified-build process that starts at chip making - simple enough to analyze and rebuild independently- to bootstrap a go runtime that provides an environment to do secure builds.

Reflections on Trusting Trust becomes even more interesting if you consider photolithography machines being backdoored.

RyanShook17 days ago

I’m of the opinion that there are backdoors in most of our software and a lot of our hardware. xz just happened to be caught because it was hogging resources.

dhx17 days ago

I think this analysis is more interesting if you consider these two events in particular:

2024-02-29: On GitHub, @teknoraver sends pull request to stop linking liblzma into libsystemd.[1]

(not in the article) 2024-03-20: The attacker is now a co-contributor for a patchset proposed to the Linux kernel, with the patchset adding the attacker as a maintainer and mirroring the attacker's activity with gaining the trust over the development of xz-utils.

A theory is that the attacker saw the sshd/libsystemd/xz-utils vector as closing soon with libsystemd removing its hard dependency on xz-utils. When building a Linux kernel image, the resulting image is compressed by default with gzip [3], but can also be optionally compressed using xz-utils (amongst other compression utilities). There's a lot of distributions of Linux which have chosen xz-utils as the method used to compress kernel images, particularly embedded Linux distributions.[4] xz-utils is even the recommended mode of compression if a small kernel build image is desired.[5]

If the attacker can execute code during the process of building a new kernel image, they can cause even more catastrophic impacts than targeting sshd. Targeting sshd was always going to be limited due to targets not exposing sshd over accessible networks, or implementing passive optical taps and real time behavioural analysis, or receiving real time alerts from servers indicative of unusual activity or data transfers. Targeting the Linux kernel would have far worse consequences possible, particularly if the attacker intended to target embedded systems (such as military transport vehicles [6]) where the chance of detection is reduced due to lack of eyeballs looking over it.







rsc17 days ago

Thanks for this comment. I've added that LKML patch set to the timeline.

delfinom17 days ago

I don't think the attacker saw the systemd change at all personally.

The way the exploit was setup, they could have pivoted to targeting basically any application server because there's so many interdependencies. python, php and ruby could be targeted because liblzma is loaded via libxml2 as an example.

Gaining trust for linux kernel commits would have just let them continue maximizing profit on their time investment.

>particularly if the attacker intended to target embedded systems (such as military transport vehicles [6])

Said vehicles aren't networked on the public internet and from experience in this particular sector, probably haven't been nor will be updated for decades. "Don't break what isn't broken" applies as well as "military doesn't have a budget to pay defense contractors $1 million to run apt-get update per vehicle".

tamimio17 days ago

> target embedded systems (such as military transport vehicles

You are giving a lot of credit to that, I have seen military ones with ancient software, even the “new” updated ones are still on ubuntu 18.04 because of some drivers/sdks compatibility, but it isn’t a major issue since most of the times they are not connected to the public internet.

daghamm17 days ago

I don't understand how this could have worked.

If you compile and build your own image, would that be able to trigger the backdoor?

You can of course change an existing image to something that triggers the backdoor, but with that level of access you won't really need a backdoor, do you?

dhx17 days ago

An attack would look something like:

1. A new "test" is added to the xz-utils repository, and when xz is being built by a distribution such as Debian, the backdoor from the "test" is included into the xz binary.

2. The backdoored xz is distributed widely, including to a target vendor who wishes to from a Debian development environment compile a kernel for an embedded device that is usually used in a specific industry and/or set of countries.

3. When backdoored xz is then asked to compress a file, it checks whether the file is a kernel image and checks whether the kernel image is for the intended target (e.g. includes specific set of drivers).

4. If the backdoored xz has found its target kernel image, search for and modify random number generation code to effectively make it deterministic. Or add a new module which listens on PF_CAN interfaces for a particular trigger and then sends malicious CAN messages over that interface. Or modify dm_crypt to overwrite the first 80% of any key with a hardcoded value. Plenty of nasty ideas are possible.

Denvercoder917 days ago

Note that none of these steps require the attacker to have any code in the kernel. The kernel patchset is completely orthogonal to the possibility of this attack, and seems to be benign.

sandstrom17 days ago

Yeah, but gaining trust with benign patchset would be the first step.

bandrami17 days ago

It's Thompson's "Trusting Trust"[1], right? To the extent XZ is part of the standard build chain you could have a source-invisible replicating vulnerability that infects everything. And if it gets into the image used for, say, a popular mobile device or IoT gadget...


fizlebit17 days ago

What are the chances this is the first such attack, not just the first one discovered. Presumably every library or service running as root is open to attack and maybe also some running in userspace. The attack surface is massive. Time for better sandboxing? Once attackers get into the build systems of Debian and others is it game over?

2OEH8eoCRo017 days ago

I wouldn't be surprised if there are others but this specific one seems special. It was caught because on connection it does an extra decryption operation and I'd assume there is no way around this extra work. They'd have to re-architect this to not require that decryption.

I'm not a security expert though.

dboreham17 days ago

Something I've wondered about wrt this debacle: presumably the smart part of xz was the compression algorithm. I'm guessing but that's probably less than 500 lines of code. The rest is plumbing to do with running the algorithm in a CLI utility, on various different OSes, on different architectures, as a library, and so on. All that stuff is at some level of abstraction the same for all things that do bulk processing on bytes of data. Therefore perhaps we should think about a scheme where the boilerplate-ish stuff is all in some framework that is well funded with people to ensure it doesn't have cutout maintainers injecting backdoors, and is re-used for hundreds of bulk-data-processing utilities; and the clever part would then be a few hundred lines of code that's easy to review, and actually probably never needs to change. Like...a separation of concerns.

calvinmorrison17 days ago

we were discussing this on the IRC. Imagine spinning up a thread, then running a bsd style pledge(2) on it to call liblzma. Kinda janky but it would work. Another option would be to just go out and call the xz util and not rely on a library to do so. That process can be locked down with pledge to only have stdin/stdout. That's all you need.

So, like UNIX does have this plumbing, its just that reaching for libraries and tight integration has been the pursuit of Lennart Poopering and his clan for years.

softwaredoug16 days ago

Is there any law enforcement at all involved in tracking down the players and trying to understand their motivations (is who is Jia Tan, etc)?

paxys16 days ago

I would be very surprised if there wasn't a Federal-level investigation being planned (or already ongoing) into this. Of course it's always a possibility that the attack was, in fact, sponsored by these same agencies.

denizens16 days ago

It's kind of funny that the attacker used a sockpuppet named "Dennis Ens."

This could be "Denizens":

- an inhabitant or occupant of a particular place.

- a person admitted to residence in a foreign country especially : an alien admitted to rights of citizenship

Good way to describe Jia Tan (singular or plural) and their sockpuppets.

klysm17 days ago

What's crazy to me about how we've set up computers to do things, is that xz itself is a pure function, but somehow there's all of this shit that has to happen to just use a pure function! It's just bytes in and bytes out, but we have an astoundingly complex build system and runtime linking system which somehow allows this pure function to run arbitrary commands on a system.

shp0ngle17 days ago

Did the Jia Tan character actually committed something of value? Looking at the history, he had (there was some stuff with multithreaded compression/decompression); as he kept it in the original license, could it be used going forward?

tamimio17 days ago

This attack doesn’t exploit a technical issue or bug, it exploits the open source philosophy, and unless the community will come up with a systematic process to counter it, expect more sophisticated attacks similar to it in the future. This time we got lucky that some smart nerd -I am a nerd too, this is a praise not to be taken in a bad way- noticed and notified the community in less than 20 days of the second backdoor implementation, next time the attack may undergoes more comprehensive “rehearsals” that it will make it impossible to detect.

luyu_wu17 days ago

Could've happened just as easily if not more easily with proprietary software.

Vegenoid17 days ago

Can you explain what aspects of the open source philosophy were exploited, and what possible mitigations might be?

peter_d_sherman17 days ago

My takeaways:

First from the article itself:

>"At this point Lasse seems to have started working even more closely with Jia Tan. Evan Boehs observes that Jigar Kumar and Dennis Ens both had nameNNN@mailhost email addresses that never appeared elsewhere on the internet, nor again in xz-devel."

That is an important observation!

Takeaway: Most non-agenda driven actual people on the Internet, leave a trail -- an actual trail of social media and other posts (and connected friends) that could be independently verified by system/social media/website administrators via voice or video calls (as opposed to CAPTCHA or other computer-based "Is it a human?" tests, which can be gamed) for stronger confidences in the identity / trustworthiness of the remote individual at the other end of a given account...

Next takeaway from the linked article: (

>"AndresFreundTec writes:

Saw sshd processes were using a surprising amount of CPU, despite immediately failing because of wrong usernames etc. Profiled sshd,

showing lots of cpu time in liblzma, with perf unable to attribute it to a symbol.

Got suspicious. Recalled that I had seen an odd valgrind complaint in automated testing of postgres, a few weeks earlier, after package updates."

Takeaway: We could always use more observability of where exactly CPU time is spent in given programs...

Binaries without symbol tables (which is the majority of programs on computers today) make this task challenging, if not downright impossible, or at least very impractical -- too complex for the average user...

Future OS designers should consider including symbol tables for all binaries they ship -- as this could open up the capability for flame graphs / detailed CPU usage profiling (and the subsequent ability to set system policies/logging around these) -- for mere mortal average users...

goombacloud17 days ago

This might not be complete because this statement "More patches that seem (even in retrospect) to be fine follow." lacks some more backing facts. There were more patches before the SSH backdoor, e.g.: "Lasse Collin has already landed four of Jia Tan’s patches, marked by “Thanks to Jia Tan”" and the other stuff before and after the 5.4 release. So far I didn't see someone make a list of all patches and gather various opinions on whether the changes could be maliciously leveraged.

VonGallifrey17 days ago

I get that there is a reason not to trust those Patches, but I would guess they don't contain anything malicious. This early part of the attack seems to only focus on installing Jia Tan as the maintainer, and they probably didn't want anything there that could tip Lasse Collin off that this "Jia" might be up to something.

rsc17 days ago

Yes, exactly. I did look at many of them, and they are innocuous. This is all aimed at setting up Jia as a trusted contributor.

goombacloud17 days ago

In one can open the patches and then click the "Changes" sub-tab. Stuff like this looks like a perf improvement but who knows if a tricky bug is introduced that was aimed to be exploited There are more patches to be vetted unless one would give up and say that 5.2 should be used as last "known-good".

kashyapc17 days ago

Given this disaster, one or other "foundation" will now embrace the `xz` project, start paying a maintainer or two so that they don't accidentally end up dying from burnout.

Rinse, repeat for all critical-path open source software. A bit like the OpenSSL "Heartbleed" disaster[1]. OpenSSL is now part of Linux Foundation's (they do a lot of great work) "Core Infrastructure Initiative".

Many fat companies build their applications on these crucial low-level libraries, and leave the drudgery to a lone maintainer in Nebraska, chugging away in his basement[2].



Brian_K_White16 days ago

Adding a new label for closing github/gitlab issues right now: "JIATAN"

Also works like Karen. "this project ...." "ok Jia"

1024core17 days ago

I am reminded of the infamous Sendmail worm from 1989(?).

If this compromised OpenSSHd had become the default across millions of systems all over the world, could a worm-like thing have brought a major chunk of the Internet down? Imagine millions of servers suddenly stuck in a boot-loop, refusing to boot.

And all because one owner of a library had some mental health issues. We should not have such SPOFs.

dijit17 days ago

> And all because one owner of a library had some mental health issues

Wrong takeaway.

juliusdavies17 days ago

Impossible here because the exploit was carefully engineered to be unreplayable and NOBUS (nobody but us) so it couldn’t go viral. Even if you intercepted a complete tcp byte trace of the attack there was nothing you could do with that to attack other systems.

thrdbndndn17 days ago

How do you get "Jigar Kumar"'s email address?

I can't seem to find it in the (web version of) the maillist.

Another question:

What is the typo exactly in this commit? I can't seem to find it.;a=commitdiff;h=a100f9111c8...

wufocaculura17 days ago

There's a single dot in a line between #include <sys/prcntl.h> and void my_sandbox(void). It is easy to miss, but makes the compile to fail, thus resulting in HAVE_LINUX_LANDLOCK to be never enabled.

arrowsmith17 days ago

Can someone explain to n00bs like me: what's "landlock" anyway and why is it significant here?

Denvercoder917 days ago

It's a Linux Security Module that allows to sandbox processes:

Thorrez17 days ago

prctl, not prcntl

swsieber17 days ago

> How do you get "Jigar Kumar"'s email address?

Hit reply

cced17 days ago

I think the period on the line above void my_sandbox.

cyberturtle14 days ago

Great summary, I also found this deep dive to be pretty helpful:

xyst17 days ago

Timeline reads like a "pig butchering" or romance scam. Except the goal is not money, but control.

Attackers find a vulnerable but critical library in the supply chain. Do a cross check on maintainers or owners of the code (reference social media and other sources to get more information). Execute social engineering attack. Talk to maintainer(s) "off list" to gain rapport. Submit a few non-consequential patches that are easy to grep to gain trust. Use history of repository or mailing list against victim to gaslight ("last release was X years ago!1", "you are letting project rOt!", "community is waiting for you!").

DrammBA17 days ago

> Timeline reads like a "pig butchering"

To me this is the polar opposite of pig butchering. This was a targeted and unromantic attack, unrelated to investing or cryptocurrency, the original maintainer was not "fattened like a hog" in any way, if anything he was bullied and abused into submission.

BuildTheRobots17 days ago

I'm amazed more people aren't talking about the "off list" part or asking Colin if he's willing to provide those emails/conversations.

xyst17 days ago

That’s more of a LEO concern. Maybe attackers got sloppy and leaked info in email headers?

pluc17 days ago

The most interesting question I have with all this is:

Do you think this was a planned effort or was it opportunistic? Did they know what they were doing and social engineered towards it, or did they figure out what to do based on the day-to-day context they discovered?

uvhug16 days ago

Maybe worth adding a link to XZ Utils backdoor by Lasse Collin to the Further Reading section

benob17 days ago

What makes you think that the accounts were not compromised only recently?

wasmitnetzen17 days ago

Not OP, but the fact that they only appear in this context makes me believe that their are specifically set up for this task. No regular person has that good opsec just to push patches to a random library.

sloowm17 days ago

If the account was compromised only recently the real co-maintainer would have done everything to warn the maintainer. If you're maintaining some core piece of infrastructure and your account gets compromised it would be trivial to let at least someone know you're not the one pushing these commits.

rattray16 days ago

Something that I feel is missing – someone please let me know if I missed it – is how long this bug was materially present in packages? how many people likely were exposed to it?

1024core17 days ago

We should set up a GoFundMe to reward Andres Freund.

riston17 days ago

xz most likely wasn't the only library that was targeted, there could be other similar projects as well which we haven't discovered yet. From the timeline you can see the social engineering part was quite big part.

Just thinking out loud, would it possible to go over with LLM and analyse existing OSS mailing lists and issues to classify such sentiment from the users?

progressof17 days ago

I have found JiaT75 - Jia Tan mentioned in Microsoft C++, C, and Assembler as an community contributor ...

Also check this...

winkelmann17 days ago

Completely benign documentation change to fix a typo:

I have no idea what that IP address is supposed to be about...

BLKNSLVR17 days ago

Regarding the AbuseIPDB link: some of the SSH payloads mentioned in the instances of 'attack' contain the username jiat75.

Doesn't necessarily validate anything though. Could be progressof planting misdirection given that the IP address only started being detected basically today (and the VPS was likely only just setup today as well, if the hostname is to be trusted).

... and that progressof's account is about an hour old.

mseepgood17 days ago

So all binaries built with a Microsoft compiler must be considered compromised?

progressof17 days ago


jhoechtl17 days ago

Care to enlighten how you come to such a knee-jerk reaction given a highly critivcal observation? What obvous are we missing?

yuriks17 days ago

It's just a documentation change. Likely made to add reputation to the account.

progressof17 days ago

I didn't come to any conclusion... and I don't think you missed anything... I'm just posting links... you think it's better if I didn't post anything because this is stupid? if so then ok...

logro17 days ago


mrbluecoat17 days ago

Best overview of the xz saga:

XorNot17 days ago

What stands out to me is this particular justification:

> 2024-02-23: Jia Tan merges hidden backdoor binary code well hidden inside some binary test input files. The associated README claims “This directory contains bunch of files to test handling of .xz, .lzma (LZMA_Alone), and .lz (lzip) files in decoder implementations. Many of the files have been created by hand with a hex editor, thus there is no better "source code" than the files themselves.”

This is, perhaps, the real thing we should think about fixing here because the justification is on the surface reasonable and the need is quite reasonable - corrupted test files to test corruption handling.

But there has got to be some a way to express this which doesn't depend on, in essence, "trust me bro" since binary files don't appear in diffs (which is to say: I can think of a number of means of doing it, but there's definitely no conventions in the community I'm aware of).

asvitkine17 days ago

Well, test files shouldn't be affecting the actual production binary.

But in practice that's not something that can be enforced for arbitrary projects without those projects having set something up specifically.

For example, the project could track the effect on binary size of the production binary after every PR. But then it still requires a human (or I guess an AI bot?) to notice that the increase would be unexpected.

erlenmayr15 days ago

Debian often removes these kind of binaries by patching the upstream tarball. When they are not used, that should be quite easy anyway. That's why the attacker put the statement in the first place. It increases the chance that distributions will accept these.

OJFord17 days ago

Also that when dynamically linking A against B, A apparently gets free reign to overwrite B.

It sort of makes sense, since at the end of the day it could just be statically linked or implement B's behaviour itself and do whatever it wants, but it's not really what you expect is it.

acdha17 days ago

Yeah, that part struck me as something we should be able to block - the number of times where you actually want that must be small enough to make it practical do something like write-protect pages with a small exception list.

erlenmayr15 days ago

He put this comment because he knows that FOSS enthusiasts and especially Debian always prefer source over binary. This is not only true for program code, but also includes docs, images etc.

The correct way to do that would be a source that generates a test file and then a script which reproducibly produces the desired corruption.

Solvency17 days ago

Why does it seem like so many open source developers suffer from chronic mental health issues? as shown here, in TempleOS, etc. It's a weird but sad pattern I see all of the time.

SalmoShalazar17 days ago

Chronic mental health issues are extremely common.

dmitrygr17 days ago

Not being paid for your work while others profit from it surely doesn’t help with one’s mental state.

hk__217 days ago

See also "Everything I Know About the XZ Backdoor" submitted 4 days ago but updated since then:

nrawe17 days ago

"It's also good to keep in mind that this is an unpaid hobby project." ~ Lasse Collin, 2022-06-08.

As someone working in security, the fact that _foundational_ pieces of the computing/networking rely on motivated individuals and essentially goodwill is mind blowing.

There are great aspects to the FOSS movement, but the risks – particularly the social engineering aspects as demonstrated here – and potential blast radius of supply chains like this... We take it all for granted and that is lining up to bite us hard, as an industry.

riskable17 days ago

This event should be a wake-up call to businesses everywhere: It's not just a small number of "core" FOSS projects that need their support (funding and assistance!). Before this event who was thinking about a compression library when considering the security of their FOSS dependencies?

The scope of "what FOSS needs to be supported and well-funded" just increased by an order of magnitude.

raxxorraxor17 days ago

This would of course be nice since the fact that so much of our infrastructure is based on the work of people sharing it openly, a practice heavily in contrast to industry behavior, is sadly still a little known fact outside of software development.

The demand for more assistance here is the angle that was played in social engineering, specifically the demand to acquire more maintainers due to workload. Especially if such support would take the form like providing source archives with manipulated build scripts that are rarely checked by third parties.

There is also a problem of badly behaving industry that tries to take control of "hobby projects". Speaking of which, these "hobby"-projects often have much better code than many, many industry codebases.

I think FOSS overall still lessens the risk. It got more risky since it has been integrated in social media since these often allow for developer being shouted down or exploited much more easily.

consp17 days ago

> allow for developer being shouted down or exploited much more easily

No is an answer. And blocking people should be a thing.

Personally I do not publish anything anymore which is not "non-commercial only" as a result of demands, you can do it yourself if you want to make money off it (or if you demand things for that matter). Fortunately my online stuff isn't used much but even then it's possible to get "requests".

jdsalaro17 days ago

> This event should be a wake-up call to businesses everywhere

This ought to be not only a wake-up call for businesses, but also to hobbyists and members of the public in general; our code, our projects and our social "code-generating systems" must be hardened or face rampant abuse and ultimately be weaponised against us.

In a way, these issues which FOSS is facing and are becoming apparent are no different to those democracy been submitted since time immemorial.

lolinder17 days ago

Funding all of these deep dependencies may have helped in this case but wouldn't address the root of the problem, which is that every business out there runs enormous amounts of unsandboxed third party code. Funding may have helped xz specifically from falling to pressure to switch to a malicious maintainer, but it does nothing about the very real risk that any one of the tens of thousands of projects we depend on has always been a long con.

The solution here has to be some combination of a dramatic cut back on the number of individual projects we rely on and well-audited technical solutions that treat all code—even FOSS dependencies—as potentially malicious and sandboxes it accordingly.

kashyapc17 days ago

Yeah, as I note elsewhere in this thread, the OpenSSL "Heartbleed" saga should've taught some lessons, but alas, it's "classic" human nature to repeat our mistakes.

mistrial917 days ago

no - funding is going to places where profit is returned on investment, NOT to the tedious and long-term work that all of this sits on. It is not "human nature" because tedious, high-skill maintenance is done by humans, which built the infrastructure and continue to be crucial.

There is no accountability and in fact high-five and star shots for those taking piles of money and placing it on more piles of money, instead of doing what appears to be obvious to almost everyone on this thread -- paying long-term engineers.

kashyapc17 days ago

No counter-argument; fully agree. FWIW, that's what I was referring to when I said, "fat companies" (and executives) glossing over the important tedious here[1].


xhkkffbf17 days ago

I'm all for funding FOSS, but how would the money have made any difference here? It just would have made Jian a bit richer, right?

jddil17 days ago

Never understood why our industry seems unique in our willingness to do unpaid work for giant corps. Your compression library isn't saving the world, it's making it easier for amazon to save a few bucks.

You have the right to be paid for your time. It's valuable.

I enjoy coding too... but the only free coding I do is for myself.

Use a proper license, charge for your time and stop killing yourself doing unpaid hobby projects that cause nothing but stress.

dugite-code17 days ago

> why our industry seems unique in our willingness to do unpaid work for giant corps.

Because it never starts that way. It scratches an itch, solves an interesting puzzle and people thank and praise the work. Deep down we all want to be useful, and it helps that it looks great on a résumé.

After it's established the big corps come along, but the feeling of community usefulness remains. It's also why so many devs burn themselves out, they don't want to disapoint.

maerF0x017 days ago

IMO this is exactly why. The payout comes later, if the project is successful.

cesarb17 days ago

> Never understood why our industry seems unique in our willingness to do unpaid work for giant corps. Your compression library isn't saving the world, it's making it easier for amazon to save a few bucks.

The work was not being done "for giant corps"; it was being done for everyone, and giant corps just happen to be a part of "everyone", together with small corps, individual people, government, and so on.

> You have the right to be paid for your time. It's valuable.

When you think of free software contributions as "volunteer labor" instead of just a hobby, it makes more sense. Yes, my time is valuable; when I'm working on free software, I'm choosing to use this valuable time to contribute to the whole world, without asking for anything in return.

aulin16 days ago

I'd say you're contributing back. You don't ask anything in return because you live in a ecosystem built on the contributions of everyone, you're just doing your part.

squigz17 days ago

Weird that this is a concept people struggle to understand...

bombcar17 days ago

Did you get paid for the post you just wrote? People at giant corps are reading it right now, they're getting value from it. You deserve to be paid!

IF you understand why you'd post without being paid, you're 80% of the way to realizing why people program without being paid.

phicoh17 days ago

I think a problem is that there doesn't seem any way to automatically check this. If we assume that anything that is used during build time can be malicious then figuring out those dependencies is already hard enough. Mapping that to organizational stability is one step further.

dylan60417 days ago

This is where the but FOSS is reviewable so it is trusted falls down. This situation is a prime example of how that fallacy is misconstrued. By being FOSS didn't make it trustworthy, it just meant that people had a fighting chance to find out why when something does happen. That's closing the barn door after the horses already left.

I'm not knocking FOSS at all. I just think some people have the concept twisted. Just like the meme of being written in Rust means the code is fast/safe from the mere fact it was written in Rust. I don't write Rust, but if I did, I guarantee that just from sheer not knowing WTF I'm doing would result in bad code. The language will not protect me from myself. FOSS will not protect the world from itself, but it does at least allow for decent investigations and after action reports.

phicoh17 days ago

We should not think in absolutes, but in terms of tools. What risks come with using a certain tool.

In your Rust example, using C is like using a power tool without any safety measures. That doesn't mean that you are going to get hurt, but there is an expectation that a sizable fraction of users of such tools will get hurt.

Rust is then the same tool with safety measures. Of course it is still a power tool, you can get hurt. But the chances of that happening during normal operation is a lot lower.

I think xz is a good example where open source happened to work as intended. Somebody noticed something weird, alerted and other people could quickly identify what other software might have the same problem.

jethro_tell17 days ago

You don't think every nation state has people inside private software shops? Especially big tech?

Look at stuff getting signed with MS keys, hardware vendors with possible backdoors.

Social engineering is social engineering and it can happen anywhere no matter the profit motivation or lack there of.

Money interest in software won't save you any more than Foss.

nrawe17 days ago
Vegenoid17 days ago

> That's closing the barn door after the horses already left.

I don't think that's quite true - maybe a couple horses got out, but this was caught early and did not get to infect very many machines because someone completely unaffiliated could review it and find it.

jrochkind117 days ago

What it reminds me of, is my reoccuring thought, not just about open source but including this aspect, that we've built up a society based on software, that we could literally only afford because we've done it unsustainably. The economy could not bear the costs of producing all this software in an actual reliable sustainable way. So... now what.

mschuster9117 days ago

It might be a good idea for governments to coordinate with computing advocacy groups/associations (e.g. German CCC, NANOG, popular Linux distributions such as Ubuntu, Debian, Fedora, Arch)... set up a fund of maybe 10 million euros, have the associations identify critical, shared components, and work out funding with their core developers. 10M a year should fund anything from 100-200 developers (assuming European wages), that should be more than enough, and it's pocket change for the G20 nations.

If that's too much bureaucracy or people fear that governments might exert undue influence: hand the money to universities, go back to the roots - many (F)OSS projects started out in universities after all. Only issue there is that projects may end up like OpenStack in the end ;)

Filligree17 days ago

Could it really not afford it? I’m not convinced that is the case, so much as we don’t have a way to pay people for their effort.

djvdq17 days ago

Nothing will really change, sadly. Remember log4j? There were also a lot of talking why people working on FOSS should be paid. And after one month almost no one remembered these voices exept for small minority of people.

JTbane17 days ago

That's just the nature of free software- you have to either trust the maintainer or do it yourself. There is not really a way around it.

- Corporate maintainers are great until they enshittify things in the pursuit of profit (see Oracle)

- Nonprofits are probably the best but can go the same route as corps (see Mozilla)

- Hobbyists are great until they burnout (see xz)

apantel17 days ago

I think the level of complexity is the problem. A bad actor can be embedded in any of the above contexts: corp, non-profit, FOSS hobbyist. It doesn’t matter. The question is: when software is so complex that no one knows what 99.9% of the code in their own stack, on their own machine, does (which is the truth for everyone here including me), how do you detect ‘bad action’?

Eisenstein17 days ago

The level of complexity involved in making sure that electrical plants work, that water gets to your home, that planes don't crash into each other, that food gets from the ground to a supermarket shelf, etc, is unfathomable and no single person knows how all of it works. Code is not some unique part of human infrastructure in this aspect. We specialize and rely on the fact that by and large, people want things to work and as long as the incentives align people won't do destructive things. There are millions of people acting in concert to keep the modern world working, every second of every day, and it is amazing that more crap isn't constantly going disastrously wrong and that when it does when are surprised.

01HNNWZ0MV43FF17 days ago

> Code is not some unique part of human infrastructure in this aspect

It kinda is. The fact that code costs fractions of a penny to copy and scale endlessly, changes everything.

There's hard limits on power plants, you need staff to run them, it's well-understood.

But software - You can make a startup with 3 people and a venture capitalist who's willing to gamble a couple million on the bet that one really good idea will make hundreds of millions.

Software actually is different. It's the only non-scarce resource. Look at the GPL - Software is the only space where communism / anarchy kinda succeeded, because you really can give away a product with _nearly_ no variable costs.

And it's really just the next step on the scale of "We need things that are dangerous" throughout all history. Observe:

- Fire is needed to cook food, but fire can burn down a whole city if it's not controlled

- Gunpowder is needed for weapons, but it can kill instantly if mishandled

- Nuclear reactors are needed for electricity, but there is no way to generate gigawatts of power in a way that those gigawatts can't theoretically cause a disaster if they escape containment

- Lithium-ion batteries are the densest batteries yet, but again they have no moral compass between "The user needs 10 amps, I'm giving 10 amps" and "This random short circuit needs 10 amps, I'm giving 10 amps"

- Software has resulted in outrageous growth and change, but just like nuclear power, it doesn't have its own morality, someone must contain it.

Even more so than lithium and nuke plants, software is a bigger lever that allows us to do more with less. Doing more with less simply means that a smaller sabotage causes more damage. It's the price of civilization.

So the genie ain't going back in. And private industry is always going to be a tragedy of the commons.

I'm not sure what government regulation can do, but there may come a point where we say, even if it means our political rivals freeload off of us, it's better for the USA to bear the cost of auditing and maintaining FOSS than to ask private corporations to bear that cost duplicating each other's work and keeping it secret.

Is that a handout to Big Tech? 100%. Balance it with UBI and a CO2 tax that coincidentally incentivizes data centers to be efficient. We'll deal with it.

emn1317 days ago

While it's interesting to philosophize about alternatives like this and it's seemingly obviously true that there's no trivial solution to maintainership that solves all problems perfectly, I'm a little wary about presenting these flawed approaches as somehow equivalent; I highly doubt they're even remotely equally bad - nor that they have equally big upsides.

agumonkey17 days ago

What's gonna happen now ? a team of foss sec chaos monkey trying to run checks on a core set of libs ?

zoeysmithe17 days ago

Sorta but flawed relevant xkcd:

I don't see how this is any strongly different than some unappreciated skill worker in a corporation. Its interesting the double standard we have for FOSS. Meanwhile in the commercial world, supply chain attacks are commonplace and barely solicit headlines.

Yes, FOSS needs to be able to address these kinds of attacks, but the world runs on the efforts of the low-level few, generally. The percent of people who work to build and maintain core infrastructure has always been small in any economic system. The world is held up by the unsung labor of the anonymous working class. Think of all the people working right now to make sure you have clean water, electricity, sanitation, etc. Its a tiny fraction of the people in your city.

Conversely, why aren't all these corporations who depend on this contributing themselves? Or reaching out? There's a real parasitic aspect here that gets swept under the rug too.

I'd even argue this isn't really a hobby for many, especially for higher profile projects. For many its done for social capital reasons to build up one's reputation which has all sorts of benefits, including corporate advancement, creating connections for startups, etc. Its career adjacent. And that's ignoring all the companies that contribute to FOSS explicitly with on-the-clock staff.

So there are motivators more than just "I'm bored and need a hobby." Its a little dismissive to call FOSS development just a hobby. Is what Linus does a hobby? I don't think most people would think so. Things like this have important social and economic motivators. The hypothetical guy in the comic isn't some weirdo doing something irrationally, but has rational motivators.

I'd also argue that its pretty harmful to FOSS adoption if the community takes on a "well, its a hobby don't expect quality, security, or professionalism." This is a great way to chase people away from FOSS. We can't just say "Oh FOSS is better than much closed software" when things are good, then immaturely reply "its just a dumb hobby, you're dumb for trusting me," when things go south. I think its pretty obvious there's a lot of defensiveness right now and people being protective over their social capital and projects, but I think this path is just the wrong way to go.

Comms, PR, and image management in FOSS is usually bad (see Linus's rage, high profile flame wars, dramatic forkings, ideological battles, etc), so optics here aren't great, because optics is something FOSS struggles with. The community is at best, herding cats, with all manner of big personalities and egos, and its usually a bit of a controlled car crash on the best of days.

phicoh17 days ago

I think there is a fundamental difference between how corporations used to work and how open source typically works.

In a traditional corporation, people would come to an office. It would be known where they live. If you would require something like (code) review, it becomes a lot harder to plant something. Obviously not impossible, but hard for all but the most dedicated attackers.

In contrast, with open source and poorly funded projects. People don't always have money to travel. So the people working on an open source project may only know each other by some online handles. Nerds typically don't like video conferencing. So it is quite possible to keep almost everything about an identity secret.

And that makes it a lot more attractive to just try something. If something goes wrong, the perpetrator is likely in a safe jurisdiction.

nradov17 days ago

True, but we have to assume that nation states are now actively inserting or recruiting intelligence agents in prominent tech companies. US authorities already caught a Saudi spy in Twitter. How many haven't been caught yet? If I was running foreign intelligence for China or Israel or any other major country I would certainly try to place agents into Google, Apple, OpenAI etc.

zoeysmithe17 days ago

tbf, most security issues aren't from some insider, but outsiders discovering exploits. The insider scenario here is extremely rare both in commercial and FOSS software.

Corporate insiders do stuff like this too, its just how often do we hear about it? FOSS has high visibility but closed source doesn't. Think of all the shady backdoors out there. Or what Snowden and others revealed.

On average a 100% FOSS organization is going to be much, much more secure than a 100% commercial close source one. Think of all the effort it takes to moderately secure a Windows/closed source stack environment. Its an entire massive industry! Crowdstrike alone has a $76bn marketcap and that's just one AV vendor!

Commercial software obeys the dictates of modern capitalism. Projects get rushed, code review and security take a backseat to quarterly reports and launch dates, etc. This makes closed source security issues common.

Usually when the exploit is discovered the attacker is far outside the victim's jurisdiction. See all the crypto gangs operating from non-Western non-extradition states.

pixl9717 days ago
singularity200117 days ago

You may want to read Kevin Mitnick on how (relatively) easy it is to infiltrate physical spaces.

Fnoord17 days ago

Mitnick, at this point, has deceased.

Read up on red teaming and social engineering in general. Many more examples of red teaming are available, for example. I thoroughly enjoy these specific stories on Darknet Diaries podcast.

asa40017 days ago

This is one of the sanest comments I've ever seen describing what FOSS actually is. I think you nailed it when you said:

> We can't just say "Oh FOSS is better than much closed software" when things are good, then immaturely reply "its just a dumb hobby, you're dumb for trusting me," when things go south.

It's weird. There are the explicit expectations of FOSS (mostly just licenses, which say very little), and the implicit expectations (everything else).

It's anarchic and ad hoc in a way that leaves the question of "what are we actually doing with this project(s)" up for all kinds of situational interpretation, as you noted. This is bad, because this ambiguity leads to conflict when the various actors are forced to reveal their expectations, and in doing so show that their expectations are actually quite divergent (i.e., "this is my fun hobby project!" vs. "my company fails without this bugfix!" vs. "I thought this was a community project!" vs. "This project is for me and my company, I call the shots, you're welcome to look at the code, though").

It's a little bit like the companies that are like "we have a flat management hierarchy, no one really reports to anyone else". It's just not true. It's almost always used as a ruse to dupe a certain class of participant that isn't sophisticated enough to know that these kinds of implicit power hierarchies leave them at a disadvantage. There's always a structure, it's just whether that structure is explicit or not. This kind of wishy-washy refusal to codify project roles/importance in FOSS is not doing us any favors. In fact I think it prevents us from actively recognizing the "clean water" role that an enormous number of projects play.

There's real labor power here if we want it, but our continued desire to have FOSS be everything to everyone is choking it.

nradov17 days ago

If you're not getting paid then it's just a hobby. And there's nothing wrong with hobbies. As a FOSS contributor myself I feel no obligation to promote FOSS adoption. Quality, security, and professionalism are not my problem; anyone who cares about those things is welcome to fork my code.

Inf0s3c17 days ago

Also in security and 100% tired of the code slingers who get annoyed by security reviews

Here on HN it’s been derided as “company just checking a box for compliance but adds no functionality. It slows us down when we want to disrupt!” - developer of yet another todo list or photo editor app…

Buffer overflows and the like are one thing. Notions from this blog that certain normal files won’t be well reviewed is a bad smell in software. Innocuous files should be just as rigorously reviewed as it’s all part of the state of the machine

“This is how it’s always worked” is terrible justification

Startup script kiddies git pulling the internet, and single maintainers open source projects aren’t cutting it; if it’s that important to the whole those in charge of the whole need to make sure it’s properly vetted.

I’m an EE first; this really just makes me want to see more software flashed into hardware.

ok12345617 days ago

A security review or snake oil AI black box didn't stop this. It was stopped by a 'code slinger' who noticed a performance regression in ssh.

Deloitte coming in a checklist would have NEVER stopped this one.

Inf0s3c17 days ago


j1elo17 days ago

A "good" side effect of this for OSS maintainers going on, is that now any time an entitled user starts being too pushy or too... well, entitled, they can be given a canned response:

Are you trying to pull an xz attack on me?

ceejayoz17 days ago

Ah, the old "undercover cops can't lie about not being a cop, just ask them" technique.

Fnoord17 days ago

If you casually ask this while you can study (and preferably record!) the person's posture and they react in real-time then you can apply interrogation technique which CIA et al use.

ceejayoz17 days ago

So becoming an open source maintainer will involve an in-person trip to an interrogation?

The xz attack involves, in significant part, a maintainer burned out and happy to accept offered help. I don't think making it substantially harder to receive genuine help is likely to improve the situation.

Fnoord17 days ago
MVQ9315 days ago


cyberturtle214 days ago


dxxvi17 days ago

I guess that Lasse Collin will have more mental health issues after all of this :-)

Do we know who really is Jia Tan? Any photo of him? The email addresses he has been using? His location?

phreeza17 days ago

What makes you think they are an actual person?

dxxvi15 days ago

You mean they are a group of people? or a computer program?

2022-06-08: Lasse Collin said that he had worked off-list a bit with Jia Tan.

I think that "off-list" means not on the xz mailing list, maybe over the personal email/phone/voice app. That's why I thought that Jia Tan was a real person

maerF0x017 days ago

Two points I'd be interested in discussing.

1. It seems a lot of people are assuming Jia Tian was compromised all along. I haven't seen a reason to believe this was a long play, but rather that they were compromised along the way (and selected for their access). Why play the long game of let's find a lone package, w/ a tired maintainer, and then try to get in good with them vs. Let's survey all packages w/ a tired maintainer, and compromise a new entrant (ie bribe/beat them).

2. IMO this also is a failing on behalf of many government agencies. NSA, NIST, FBI all should, IMO spend less time compromising their own citizenry, and more time focusing on shoring up the security risks Americans face.

nebulous117 days ago

Completely conclusive proof? No, but it seems unlikely that there ever would be conclusive proof of such.

They don't seem to exist outside of this incident and things related to this.

There were multiple people who also don't seem to exist outside of their posts to the xz mailing list applying pressure for the original maintainer to bring Jia on board. This occurred around the time that Jia was first making contact with the project, not only recently.

Apparently the IP addresses that were logged for Jia is a VPN based in Singapore

They have vanished.

Honestly, there's very little evidence that they weren't always intending this.

doakes17 days ago

What's your source for the IP addresses?

orkj17 days ago

It's mentioned in one of the first references in this article:

IRC activity

nebulous117 days ago

I can't remember where I read that but it would likely have been from a HN link or possibly a comment.

I just found this: which is definitely not where I originally read it, but libera is probably ultimately the source

PUSH_AX17 days ago

> It seems a lot of people are assuming Jia Tian was compromised all along. I haven't seen a reason to believe this was a long play, but rather that they were compromised along the way

So I assume Jia has spoken out since? How do you go this long without realising someone else is making plays as you?

saulpw17 days ago

I took a look at Jia Tan's early behavior, and I found it to be consistent with being "compromised" from the beginning. They had months of contributions on private repos before forking a test library and making superficial changes to it, and then diving headlong into archival libraries. It all looks set up and I see no evidence of an actual person at any point.

I also think it is more difficult to get away with bribing/beating an existing contributing than you suggest; esp since failure means likely exposure.

lmkg17 days ago

Regarding point 1: The timeline in the linked article describes some communications as "pressure emails." I've heard the theory, but haven't seen solid evidence, that the pressure emails weren't just regular impatience from outside devs, but actually part of the attack. To convince the primary maintainer into granting access to another party.

maerF0x017 days ago

Occams Razor and a variation on Hanlon's razor to me suggest that Jia actually wanted to solve the issues and work on code. They contributed some things to other repos too, correct? (I saw another thread about microsoft documentation, for eg).

Here's the thing, if the maintainer was so tired and needed the help, the pressure is more risk than reward. The maintainer would be relieved to have help... But pressure risks estranging...

To be clear I'm aware this is just my own musing though.

softwaredoug17 days ago

Open Source is a real tragedy of the commons.

Everyone wants to consume it. Nobody wants to participate.

People are upset when a company like Elastic or Mongo switches to a "non open" license. But at the same time, the market doesn't leave much choice. Companies won't be incentivized to contribute to projects when they can freeload. The market actually wants vendors, it doesn't want to participate in open source. But they don't want to _pay_ for vendors.

So I think its entirely appropriate that anyone / any entity that creates "open source" to change their license, set limits, say "no", and let users be damed unless they're willing to make it financially appealing. It's literally "Without Warranty" for a reason.

Letting your passion project becoming hijacked into determining your mental health is really depressing. F' the people who can't get on board with your boundaries, etc around it. They deserve the natural consequences of their lack of support.

rwmj17 days ago

Yeah whatever. Closed source software is much easier to subvert, just have your agents join the company and they can push whatever they want without any external (or even internal) review.