PLEASE. I keep seeing it in memes. As I understand it the latest version of the xz package (present in rolling release distros like Arch and SUSE Tumbleweed) has “a backdoor”, but I have no earthly clue what can be done by malicious folks with access to that backdoor or if I should be afraid or how to check if my distro is compromised or how to prevent damage if it is or (…)
You must log in or register to comment.
Fairly simple explanation by arstechnica: “The malicious versions [of xz], researchers said, intentionally interfere with authentication performed by SSH, a commonly used protocol for connecting remotely to systems. SSH provides robust encryption to ensure that only authorized parties connect to a remote system. The backdoor is designed to allow a malicious actor to break the authentication and, from there, gain unauthorized access to the entire system. The backdoor works by injecting code during a key phase of the login process.”
Also from the article, you should check if your distro is offering a downgrade from the affected 5.6.x packages. Right now the exploit is not fully understood. For example, openSUSE recommends a full reinstall of Tumbleweed if an SSH server was enabled, just to mitigate risk.
I was on EndeavourOS (Arch-derived), but switched to SUSE Tumbleweed like, this weekend.
But hold up
So if the backdoor is all about exploiting ssh to gain full system access, and ssh was never enabled in my OS I’m in the clear regardless?
While the full extent of the exploit is not fully known, it seems specifically targeted at the sshd binary on deb and rpm based systems. If you’ve got that service disabled it should not have been running actively on your system. You should still perform whatever is needed to downgrade, but I would say you’re in the clear.
What if you had the service enabled on an Arch based distro?
Each distribution is different but Arch has stated that they did have the exploit artifact in their version of xz but the artifact was not loaded into memory with sshd as their process does not link sshd with liblzma library.
More details below but highly recommend upgrade/downgrade anyways to remove the exploit code version.
https://archlinux.org/news/the-xz-package-has-been-backdoored/
