ELI5 what does this mean for the average Linux user? I run a few Ubuntu 22.04 systems (yeah yeah, I know, canonical schmanonical) - but they aren’t bleeding edge, so they shouldn’t exhibit this vulnerability, right?
apt info xz-utils
Your version is old as balls. Even if you were on Mantic, it would still be old as balls.
Security through antiquity
The average user? Nothing. Mostly it just affects those who get the newest versions of everything.
In this case I think that’s just Fedora and Debian Sid users or so.
The backdoor only activates during DEB or RPM builds, and was quickly discovered so only rolling release distros using either package format were affected.
Lzma balls
Damn, it is actually scary that they managed to pull this off. The backdoor came from the second-largest contributor to xz too, not some random drive-by.
Time to audit all there contributions although it looks like they mostly contribute to xz. I guess we’ll have to wait for comments from the rest of the team or if the whole org needs to be considered comprimised.
They’ve been contributing to xz for two years, and commited various “test” binary files.
It’s looking more like a long game to compromise an upstream.
Either that or the attacker was very good at choosing their puppet…
Well the account is focused on one particular project which makes sense if you expect to get burned at some point and don’t want all your other exploits to be detected. It looks like there was a second sock puppet account involved in the original attack vector support code.
We should certainly audit other projects for similar changes from other psudoanonymous accounts.
Yeah, and the 700 commits should be reverted… just in case we missed something.
That is a should be standard procedure
It would be nice if we could press formal charges
Assuming that it’s just that person, that it’s their actual name and that they’re in the US…
there will be federal investigation
Do you have a source for this?
I don’t have a source but I think it is safe to say given the large corporations and government institutions that rely on XZ utils. I’m sure Microsoft, Amazon, redhat ect are in talks with the federal government about this
Source: they made it up
updated my post, it was just some speculation i misread
Here is the official statement from OpenSUSE: https://news.opensuse.org/2024/03/29/xz-backdoor/
This is pretty insane. Can’t wait for the Darknet Diaries on this one.
I will laugh out loud if the “fixed” binary contains a second backdoor, but one of better quality. It’s reminiscent of a poorly hidden small joint, which is naturally found, and then bargaining, apologizing and making amends begin. Although now it is generally not clear where the code is more proven.
Holly shit
Reading the comments here https://news.ycombinator.com/item?id=39865810 it appears that libarchive may be tainted as well.
Is this only happened with SSH, or other network facing services using liblzma too?
The malicious code attempts to hook in to libcrypto, so potentially other services that use libcrypto could be affected too. I don’t think extensive research has been done on this yet.
SSH doesn’t even use liblzma. It’s pulling in the malicious code via libsystemd, which does use liblzma.
Edit: “crypto” meaning cryptography of course, not cryptocurrency.
We know that sshd is targeted but we don’t know the full extent of the attack yet.
Also, even aside from the attack code here having unknown implications, the attacker made extensive commits to liblzma over quite a period of time, and added a lot of binary test files to the xz repo that were similar to the one that hid the exploit code here. He also was signing releases for some time prior to this, and could have released a signed tarball that differed from the git repository, as he did here. The 0.6.0 and 0.6.1 releases were contained to this backdoor aimed at sshd, but it’s not impossible that he could have added vulnerabilities prior to this. Xz is used during the Debian packaging process, so code he could change is active during some kind of sensitive points on a lot of systems.
It is entirely possible that this is the first vulnerability that the attacker added, and that all the prior work was to build trust. But…it’s not impossible that there were prior attacks.
Some no-name came and without any problems asked to become a maintainer in a project used in almost any distro, took it over, put a backdoor in there and no one had any questions? In this case, everything turned out thanks to pure chance. Noname screwed up his backdoor, which attracted the attention of a guy from Microsoft, and out of boredom, he dug up what was what. And if I hadn’t messed up, or that guy from Microsoft decided to go drink beer instead of poking around in the xz code, then no one would have discovered anything. It’s scary to imagine how many of these nonames are sitting in all these thousands of open source projects, waiting in the wings to roll out a malicious patch.
They noticed that some ssh sessions took 0.5 seconds too long under certain circumstances. 😲
Holy hell that’s good QA.
Well half a second delay is pretty noticeable when you ssh into a machine sitting right next to you. It should be instant. And if it isn’t something’s off.
Microsoft employee.
Don’t see why you’re being downvoted, the person in question who discovered this is a postgres maintainer employed by Microsoft.
Probably people think this is a troll or something.
I wrote it because I was surprised, especially since I’m not a fan of microsoft and their policies. Lately, I have the feeling Microsoft is better than Google (relative terms) when it comes to oss.
What is additionally surprising is the breaches of Microsoft services in the last year. There is one every few weeks or so… And then they pick up a backdoor because login took 0.5 instead of 0.1s.
Anyway, his findings are amazing.
This isn’t the same thing, but I’m reminded of Minecraft.
Minecraft is a massively popular game. Notch once said he planned to make it open source when its popularity died down. But now Microsoft owns it.
Not only that, but Mojang accounts don’t work anymore. You have to have a Microsoft account to play it now. Even trying to download and play an older version of the game offline requires Microsoft to approve it. Microsoft is actively tightening the leash on the game because it makes them money. Open sourcing the game will likely never happen now. The best we can hope for it for versions to fall into public domain after 70-ish years.
That’s how I see Microsoft. They only care about what its beneficial for them to drive profits. Working on open source projects, and open sourcing a few of their tools to get the benefits of community adoption and code review is great, sure. But they’d sooner try to incorporate Linux into Windows to keep people in their surveillance ecosystem, than to open source Windows.
Remember when Windows 10 was the last version, until they changed their minds? Remember when they floated the idea of charging a recurring subscription to use Windows, before they silently dropped the idea? Remember when there was credible talk about the next version of Windows being cloud-based where they controlled all your data and you had no privacy? Hell, you have basically no privacy on Windows 10. Trying to reclaim some involves registry edits, special third party tools, and a constant battle with automatic updates reverting your changes.
I’ll say it again. Microsoft doesn’t care about OSS. It’s just currently beneficial for them to pretend they do.
Goggle seemed to care a lot about OSS, then started making everything in Android depend on their proprietary ecosystem to function. Now Google is using the dominant position they got by taking advantage of OSS adoption, and have been pushing privacy-invading standards and trying to get rid of ad blockers online, among many other things.
For these huge companies, OSS is just a tool to get more control and power. The moment it’s no longer useful, they’ll find ways to work around the license and enshitify everything again.
It keeps happening. I refuse to keep trusting bad actors every time they dangle a shiny trinket over our heads.
I do appreciate the work this person did in finding the bug. It’s not all doom and gloom.
I agree with you sentiment here. That’s why I wrote ‘relative terms’ in my comment.
Since Nadela took over, Microsoft did some open thing which benefited community. So, Microsoft opened somewhat.
During the same time, under Pichai, google went the other way: they focus more on monetization and try to control stuff the apple way. Manifest v3? Google also didn’t do anything really worth mentioning in the last 10y in terms of products. Well, except ‘attention’ article. And even this they didn’t believe in and they cannot deliver a decent product. I just tried google advanced Gemini and it’s, to put it politely, shit. Google also had some positive actions like mainlining a lot of stuff in Linux Kernel to more easily upgrade android.
So, while google is closing down and making mistakes, Microsoft is opening a bit up.
If you look the state from the last year and the state now. Microsoft improved. Google went the other way.
Microsoft doesn’t care about open source, they care about the money Cloud Services using open source bring them. I don’t think google cares as well. For reason read this: https://www.joelonsoftware.com/2002/06/12/strategy-letter-v/
Definitely not from the team working on search on Windows then.
deleted by creator
If you’re using
xz
version 5.6.0 or 5.6.1, please upgrade asap, especially if you’re using a rolling-release distro like Arch or its derivatives. Arch has rolled out the patched version a few hours ago.Backdoor only gets inserted when building RPM or DEB. So while updating frequently is a good idea, it won’t change anything for Arch users today.
when building RPM or DEB.
Which ones? Everything I run seems to be clear.
https://access.redhat.com/security/cve/CVE-2024-3094
Products / Services Components State Enterprise Linux 6 xz Not affected Enterprise Linux 7 xz Not affected Enterprise Linux 8 xz Not affected Enterprise Linux 9 xz Not affected (and thus all the bug-for-bug clones)
Fedora 41, Fedora Rawhide, Debian Sid are the currently known affected ones AFAIK.
Those getting the most recent software versions, so nothing that should be running in a server.
No, read the link you posted:
Arch does not directly link openssh to liblzma, and thus this attack vector is not possible. You can confirm this by issuing the following command:
ldd "$(command -v sshd)"
However, out of an abundance of caution, we advise users to remove the malicious code from their system by upgrading either way.
I think that was a precaution. The malicious build script ran during the build, but the backdoor itself was most likely not included in the resuling package as it checked for specific packaging systems.
Gentoo just reverted back to the last tar signed by another author than the one seeming responsible for the backdoor. The person has been on the project for years, so one should keep up to date and possibly revert even further back than just from 5.6.*. Gentoo just reverted to 5.4.2.
Just updated on void and saw the same thing
Dang, Arch never sleeps, does it? That’s a 24/7 incident response squad level of support.
This is a fun one we’re gonna be hearing about for a while…
It’s fortunate it was discovered before any major releases of non-rolling-release distros were cut, but damn.
That’s the scary thing. It looks like this narrowly missed getting into Debian and RH. Downstream downstream that is… everything.