A remote code execution vulnerability was identified in GitHub Enterprise Server in the Git service…

Why it is Yellow

• CVSS 7.7 high

References

• https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.14
• https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.10
• https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.8
• https://docs.github.com/en/enterprise-server@3.22/admin/release-notes#3.22.3

Original description

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.