High advisory for A remote code execution vulnerability wa

Advisory overview

A remote code execution vulnerability was identified in GitHub Enterprise Server in the Git service (babeld). babeld held references into internal collections while calling into the SSH library, where a re-entrant callback could modify a collection and invalidate those references. An attacker with an account and SSH access to the instance could leverage this use-after-free into a controlled write and run arbitrary commands as babeld, including disclosure of its environment secrets. Exploitation required per-build memory offsets; failed attempts crashed babeld. This affected all releases prior to 3.23 and was fixed in 3.22.3, 3.21.8, 3.20.10, and 3.19.14. This vulnerability was reported via the GitHub Bug Bounty program.

Related references

• https://docs.github.com/en/[email protected]/admin/release-notes#3.19.14
• https://docs.github.com/en/[email protected]/admin/release-notes#3.20.10
• https://docs.github.com/en/[email protected]/admin/release-notes#3.21.8
• https://docs.github.com/en/[email protected]/admin/release-notes#3.22.3