DescriptionMalicious 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
xz-utils (PTS)bullseye (security), bullseye5.2.5-2.1~deb11u1fixed
sid, trixie5.6.2-2fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
xz-utilssourcebuster(not affected)
xz-utilssourcebullseye(not affected)
xz-utilssourcebookworm(not affected)


[bookworm] - xz-utils <not-affected> (Vulnerable code not present)
[bullseye] - xz-utils <not-affected> (Vulnerable code not present)
[buster] - xz-utils <not-affected> (Vulnerable code not present)

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