XZ Utils backdoor attempt proves the value of code provenance

A malicious maintainer slipped an obfuscated backdoor into the widely used XZ Utils compression library, targeting SSH authentication.

Early detection by open-source contributors prevented mass compromise of Linux distributions, but the campaign highlighted maintainer fatigue.

Prevention playbook:

• Perform supply-chain risk assessments on open-source dependencies, including contributor trust scoring.
• Use reproducible builds, signature verification, and SBOM tooling to detect tampering before deployment.
• Isolate CI/CD runners, monitor for abnormal maintainer activity, and require multi-party approvals.