Improper authorization fallback allows scoped user-to-server token installation escape in GitHub Enterprise Server
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.2epss 0.2%
exploitation probability
0.2%top 86% of all CVEs
observed exploitation
nono source reports it
An improper authorization vulnerability in scoped user-to-server (ghu_) token authorization in GitHub Enterprise Server allows an authenticated attacker to access private repositories outside the intended installation scope, which can include write operations, via an authorization fallback that treated a revoked/deleted installation as a global installation context, which could be chained with token revocation timing and SSH push attribution to obtain and reuse a victim-scoped token. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, and 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N
Affected products
GitHub · Enterprise ServerReferences
https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.26https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.21https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.17https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.14https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.8https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.5https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.1