Comment on How does the xz incident impacts the average user ? #xz
neatchee@lemmy.world 7 months ago
Quick summary:
- only impacts Debian and Linux distributions that utilize RPM for packages
- only impacts cases where liblzma is compiled from a tarball, rather than cloned source repository or precompiled binary
- only impacts x64 architecture
- introduced in liblzma 5.6.0 which was released in late February so only impacts installs receiving updates to liblzma since then
liblzma is a library for the lzma compression format. Loosely, this means it’s used by various other pieces of software that need this type of compression, rather than being an application itself.
It is very widely used. It comes installed on most major Linux distributions and is used by software like openssh, one of the standard remote connection packages.
However, since it was only in the tarball, you wouldn’t see it widely until debian, fedora, et al release a new version that includes the latest liblzma updates. This version hadn’t been added to any of the stable release channels yet, so the typical user wouldn’t have gotten it yet.
I believe this would have gone out in debian 12.6 next week, and the attacker was actively petitioning fedora maintainers to get it added to fedora 40 & 41
The interesting thing about this situation was how much effort the attacker put in to gain trust just to get to the point where they could do this, and how targeted the vulnerability seems to have been. They tried very hard to reduce the likelihood of being caught by only hitting a limited set of configurations
Jimmycrackcrack@lemmy.ml 7 months ago
I’m still confused exactly what the circumstances would be where this worked as the attacker intended. Would simply having the infected liblzma version on the system create the vulnerability or does something have to happen to invoke it and then what? What’s he chain of events that would have happened had this worked perfectly and gone undetected? I tried to read some of the more detailed analysis but the stuff went way over my head.
Also, what about Mac OS? Can the package create any vulnerability there if installed via homebrew as it’s reported to have done in some cases? Or is that environment also not right for it to work?
neatchee@lemmy.world 7 months ago
Here’s how it was intended to work:
NeatNit@discuss.tchncs.de 7 months ago
Thank you! I believe this is what the OP was asking, and it’s definitely what I wanted to know :)
Do we know what the payload is?
neatchee@lemmy.world 7 months ago
Arbitrary. It could be whatever they wanted at any time