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.
References
- http://www.openwall.com/lists/oss-security/2024/03/29/10
- http://www.openwall.com/lists/oss-security/2024/03/29/12
- http://www.openwall.com/lists/oss-security/2024/03/29/4
- http://www.openwall.com/lists/oss-security/2024/03/29/5
- http://www.openwall.com/lists/oss-security/2024/03/29/8
- http://www.openwall.com/lists/oss-security/2024/03/30/12
- http://www.openwall.com/lists/oss-security/2024/03/30/27
- http://www.openwall.com/lists/oss-security/2024/03/30/36
- http://www.openwall.com/lists/oss-security/2024/03/30/5
- http://www.openwall.com/lists/oss-security/2024/04/16/5
- https://access.redhat.com/security/cve/CVE-2024-3094
- https://ariadne.space/2024/04/02/the-xz-utils-backdoor-is-a-symptom-of-a-larger-problem/
- https://arstechnica.com/security/2024/03/backdoor-found-in-widely-used-linux-utility-breaks-encrypted-ssh-connections/
- https://aws.amazon.com/security/security-bulletins/AWS-2024-002/
- https://blog.netbsd.org/tnf/entry/statement_on_backdoor_in_xz
- https://boehs.org/node/everything-i-know-about-the-xz-backdoor
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1068024
- https://bugs.gentoo.org/928134
- https://bugzilla.redhat.com/show_bug.cgi?id=2272210
- https://bugzilla.suse.com/show_bug.cgi?id=1222124
- https://discourse.nixos.org/t/cve-2024-3094-malicious-code-in-xz-5-6-0-and-5-6-1-tarballs/42405
- https://gist.github.com/thesamesam/223949d5a074ebc3dce9ee78baad9e27
- https://github.com/advisories/GHSA-rxwq-x6h5-x525
- https://github.com/amlweems/xzbot
- https://github.com/karcherm/xz-malware
- https://gynvael.coldwind.pl/?lang=en&id=782
- https://lists.debian.org/debian-security-announce/2024/msg00057.html
- https://lists.freebsd.org/archives/freebsd-security/2024-March/000248.html
- https://lwn.net/Articles/967180/
- https://news.ycombinator.com/item?id=39865810
- https://news.ycombinator.com/item?id=39877267
- https://news.ycombinator.com/item?id=39895344
- https://openssf.org/blog/2024/03/30/xz-backdoor-cve-2024-3094/
- https://research.swtch.com/xz-script
- https://research.swtch.com/xz-timeline
- https://security-tracker.debian.org/tracker/CVE-2024-3094
- https://security.alpinelinux.org/vuln/CVE-2024-3094
- https://security.archlinux.org/CVE-2024-3094
- https://security.netapp.com/advisory/ntap-20240402-0001/
- https://tukaani.org/xz-backdoor/
- https://twitter.com/LetsDefendIO/status/1774804387417751958
- https://twitter.com/debian/status/1774219194638409898
- https://twitter.com/infosecb/status/1774595540233167206
- https://twitter.com/infosecb/status/1774597228864139400
- https://ubuntu.com/security/CVE-2024-3094
- https://www.binarly.io/blog/persistent-risk-xz-utils-backdoor-still-lurking-in-docker-images
- https://www.cisa.gov/news-events/alerts/2024/03/29/reported-supply-chain-compromise-affecting-xz-utils-data-compression-library-cve-2024-3094
- https://www.darkreading.com/vulnerabilities-threats/are-you-affected-by-the-backdoor-in-xz-utils
- https://www.kali.org/blog/about-the-xz-backdoor/
- https://www.openwall.com/lists/oss-security/2024/03/29/4
- https://www.redhat.com/en/blog/urgent-security-alert-fedora-41-and-rawhide-users
- https://www.tenable.com/blog/frequently-asked-questions-cve-2024-3094-supply-chain-backdoor-in-xz-utils
- https://www.theregister.com/2024/03/29/malicious_backdoor_xz/
- https://www.vicarius.io/vsociety/vulnerabilities/cve-2024-3094
- https://xeiaso.net/notes/2024/xz-vuln/