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Reflections on Distrusting xz

joeyh.name

61–70 of 335 posts

Re: Reflections on Distrusting xz

#61
post #50
post #8

One thing that comes to mind is that “Jia Tan” might be more accurately seen as a “sleeper” of some sort: a foot soldier who infiltrates a juicy open source project and waits for further instructions; backdooring sshd might not have been part of the original plan. Which raises the concerning question of how much more sleeper maintainers there are.

Everyone working on important open source code should have a real identity associated with them. The fact that "Jia Tan" was able to become a maintainer without anyone ever trying to figure out their real identity shows a huge weakness in our trust model in OSS (everyone real would have something like a Linked In page, Facebook, Twitter, Instagram, or better, their own website with stuff that could be used to ensure…

No-one working on open source code on their time owes anything to anyone using the code. If you want an important open source project to be maintaned by non-anonymous person, surprise-surprise, hire that person and pay them.

Besides, some of the best open source contributors I know are almost-anonymous people behind nicknames and anime girls avatars.

Re: Reflections on Distrusting xz

#62
post #8

One thing that comes to mind is that “Jia Tan” might be more accurately seen as a “sleeper” of some sort: a foot soldier who infiltrates a juicy open source project and waits for further instructions; backdooring sshd might not have been part of the original plan. Which raises the concerning question of how much more sleeper maintainers there are.

>Which raises the concerning question of how much more sleeper maintainers there are.

Given how easy the infiltration is and how extremely hard to detect it is, likely a lot.

For an intelligence operation it is also extremely cheap, you just need a few knowledgeable developers spending some time each week on the project. The upside being a backdoor into a significant portion of infrastructure, the downside being wasted time.

I do not think it is unlikely that in many important open source software projects there are one or two people assign to keep an eye on things. They don't even need to be malicious, just being somewhat trusted contributors is enough. I would be extremely surprised if the NSA hasn't a couple of guys who keep watch on the Linux Kernel.

Re: Reflections on Distrusting xz

#63

There seems to be a fundamental misunderstanding with a lot of these writeups. Are they 100% sure history was not rewritten at any point? Going back in time on the repo prior to listed involvement doesn't do anything as the attacker had full control. Starting from the last signed release prior to their involvement is the only way to actually move this forward (history may be fully lost at this point), the rest is pos…

Even history rewrites would be visible with Github's new Activity tab, e.g., see the two force-pushes in llama.cpp https://github.com/ggerganov/llama.cpp/activity So, while, yes, git history can be rewritten, commits pushed to Github can effectively never be deleted. Personally, I find this to be a downside. Think, personal information, etc. But, in this case, it is helpful. Of course, the repository is suspended right now, so the Activity cannot be checked.

Re: Reflections on Distrusting xz

#64

There seems to be a fundamental misunderstanding with a lot of these writeups. Are they 100% sure history was not rewritten at any point? Going back in time on the repo prior to listed involvement doesn't do anything as the attacker had full control. Starting from the last signed release prior to their involvement is the only way to actually move this forward (history may be fully lost at this point), the rest is pos…

In any case Debian has its own archive of every xz-utils version they've used in the past.

Re: Reflections on Distrusting xz

#65
post #9

It's like security 101. If a system has been infiltrated, you can't trust any part of it. So it's better to discard any part that has been reached or possibly affected. Perhaps it's the correct action to distrust xz/lzma or any source code this team has control over and switch to alternatives. If there are no alternatives, to start ones.

Hiding more backdoors in the library would only increase the risk of getting discovered. Care is certainly advised on the source level, but I'd leave the paranoia to the state of systems where the code has run.

From the attackers' perspective, what they'd want to do is use their project infiltration success as little as possible, only enough to squeeze in other backdoors completely unrelated to xz. But that's all operations, not development.

Re: Reflections on Distrusting xz

#66
post #50
post #8

One thing that comes to mind is that “Jia Tan” might be more accurately seen as a “sleeper” of some sort: a foot soldier who infiltrates a juicy open source project and waits for further instructions; backdooring sshd might not have been part of the original plan. Which raises the concerning question of how much more sleeper maintainers there are.

Everyone working on important open source code should have a real identity associated with them. The fact that "Jia Tan" was able to become a maintainer without anyone ever trying to figure out their real identity shows a huge weakness in our trust model in OSS (everyone real would have something like a Linked In page, Facebook, Twitter, Instagram, or better, their own website with stuff that could be used to ensure…

Who are you to propose requirements onto people who work for free?

Re: Reflections on Distrusting xz

#67
post #8

One thing that comes to mind is that “Jia Tan” might be more accurately seen as a “sleeper” of some sort: a foot soldier who infiltrates a juicy open source project and waits for further instructions; backdooring sshd might not have been part of the original plan. Which raises the concerning question of how much more sleeper maintainers there are.

I believe this is a nation state actor and there are a a fleet of 'Jia Tans' working on other OSS projects to backdoor operating systems. And some have probably succeeded.

I believe the term "nation state actor" is a term that means "country" but with the bonus of connoting that the writer is an armchair infosec wizard. This speculation is not valuable without adding information, otherwise it's just McCarthyist bluster.

Re: Reflections on Distrusting xz

#69
post #52

Earlier quoted context omitted.

I believe this is a nation state actor and there are a a fleet of 'Jia Tans' working on other OSS projects to backdoor operating systems. And some have probably succeeded.

At this point, considering the apparent ease with which a project that is used pretty much everywhere was taken over, that seems like a reasonable position.

I can walk out on the street and stab someone to death if I wanted to. This is surprisingly easy.

Just because something is relatively easy to pull off doesn't mean it happens a lot.

It's also not that easy to pull off because you need to have a project with relatively few eyes and a place to hide it. In this case: binary tests. But most projects don't have those.

There is no evidence for any of this, including that it's a nation-state actor. There's also a case to be made that it's NOT a nation-state actor as nation states use Linux and want a secure Linux. The NSA and such have somewhat conflicting interests here. We just don't know. It's likely we will never know.

All of this is starting to resemble the spy paranoia of the first world war. A few spies got caught and suddenly everyone was now a suspected German spy (including a general, if I recall correctly, who was detained for a while because he couldn't answer a question about baseball or some such).

I suspect that very soon people will start demanding maintainers put some of their blood in a Petri dish to be tested with a hot needle. Just in case.

Re: Reflections on Distrusting xz

#70
post #14

Trusting anything from that actor is full on ignorant, let alone "a new decoder". It's insane.

Trusting people in general is inadvisable. I haven't trusted anyone for years and I am richer than ever.

You probably still rely on trusting others a lot more than you realize.

If you really, really, didn’t rely on trusting anyone, I don’t even see how it would be possible to exist on earth.

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