Vulnerability Discovered in xz Libraries
An urgent alert for Fedora 40 has been posted and users should pay attention.
On March 28, the Fedora community received word about CVE-2024-3094, which impacted any instance of Fedora 40 that used repositories outside of the stable branch.
The vulnerability is found in the upstream tarballs of the xz application, which is a compression tool that has been around for a long time.
CVE-2024-3094 is marked as critical with a score of 10, which means it is of the highest severity and should be taken seriously.
The issue affects versions 5.6.0 and 5.6.1 of the xz libraries and is only found in the tarball download package (and not the Git distribution, which lacks the M4 macro trigger).
According to the Red Hat Customer Portal, "Malicious code was discovered in the upstream tarballs of xz, starting with version 5.6.0. Through a series of complex obfuscations, the liblzma build process extracts a prebuilt object file from a disguised test file existing in the source code, which is then used to modify specific functions in the liblzma code. This results in a modified liblzma library that can be used by any software linked against this library, intercepting and modifying the data interaction with this library."
If you're a Fedora 40 beta user, you can resolve this issue by downgrading xz from the testing repositories by issuing the command sudo dnf upgrade --refresh --advisory=FEDORA-2024-d02c7bb266. If you find the command doesn't work, try again later.
