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.
Those getting the most recent software versions, so nothing that should be running in a server.
Fedora 41, Fedora Rawhide, Debian Sid are the currently known affected ones AFAIK.
I think it needs to be
rolling release (because it was caught so quickly that it hasn't made its way into any cadence based distro yet)
using the upstream Makefile task to build a RPM or DEB (because the compromised build script directly checks for that and therefore doesn't trigger for a destdir build like Gentoo’s or Arch’s)
using the upstream provided tarball as opposed to the one GitHub provides, or a git clone (because only that contains the compromised Makefile, running autotools yourself is safe)
Points 1 and 2 mean that only rolling release RPM and DEB distros like Debian Sid and Fedora are candidates. I didn't check if they use the Makefile and the compromised tarballs.
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.
Archlinux's XZ was compromised as well.
News post
Git change for not using tarballs from source
No, read the link you posted:
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.
https://www.openwall.com/lists/oss-security/2024/03/29/22
Which ones? Everything I run seems to be clear.
https://access.redhat.com/security/cve/CVE-2024-3094
(and thus all the bug-for-bug clones)
Those getting the most recent software versions, so nothing that should be running in a server.
Fedora 41, Fedora Rawhide, Debian Sid are the currently known affected ones AFAIK.
I think it needs to be
Points 1 and 2 mean that only rolling release RPM and DEB distros like Debian Sid and Fedora are candidates. I didn't check if they use the Makefile and the compromised tarballs.