An improper verification of cryptographic signature vulnerability was identified in GitHub Enterprise Server that allowed SAML SSO authentication to be bypassed resulting in unauthorized provisioning of users and access to the instance. Exploitation required the encrypted assertions feature to be enabled, and the attacker would require direct network access as well as a signed SAML response or metadata document. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.15 and was fixed in versions 3.11.16, 3.12.10, 3.13.5, and 3.14.2. This vulnerability was reported via the GitHub Bug Bounty program.

GitHub, Inc. (Products Only) CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:U/V:C/RE:M/U:Red

GitHub, Inc. (Products Only) CWE-347

GitHub, Inc. (Products Only) https://docs.github.com/en/enterprise-server@3.11/admin/release-notes#3.11.16 [No types assigned]

GitHub, Inc. (Products Only) https://docs.github.com/en/enterprise-server@3.12/admin/release-notes#3.12.10 [No types assigned]

GitHub, Inc. (Products Only) https://docs.github.com/en/enterprise-server@3.13/admin/release-notes#3.13.5 [No types assigned]

GitHub, Inc. (Products Only) https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.2 [No types assigned]