An Improper Verification of Cryptographic Signature vulnerability was identified in GitHub Enterprise Server that allowed SAML SSO authentication to be bypassed

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• github enterprise serverbefore 3.11.16
• github enterprise server3.12.0 and later · before 3.12.10
• github enterprise server3.13.0 and later · before 3.13.5
• github enterprise server3.14.0 and later · before 3.14.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_P). Independent of NVD's CPE analysis and usually ahead of it.

• GitHub Enterprise Server

  • 3.11.0 and later · up to and including 3.11.15affected · semverfixed in 3.11.16
  • 3.12.0 and later · up to and including 3.12.9affected · semverfixed in 3.12.10
  • 3.13.0 and later · up to and including 3.13.4affected · semverfixed in 3.13.5
  • 3.14.0 and later · up to and including 3.14.1affected · semverfixed in 3.14.2

Other highest-scoring records for the same primary product.

• CVE-2024-0200Unsafe Reflection in Github Enterprise Server leading to Command Injection
  61This week
• CVE-2024-0507Privilege Escalation by Code Injection in the Management Console in GitHub Enterprise Server
  55Plan
• CVE-2024-4985An authentication bypass vulnerability was present in the GitHub Enterprise Server (GHES) when utilizing SAML single sign-on authentication
  41Plan
• CVE-2022-23739Incorrect authorization check in GitHub Enterprise Server leading to escalation of privileges in GraphQL API requests from GitHub Apps using scoped user-to-serv
  39Monitor
• CVE-2022-46255Improper Limitation of a Pathname to a Restricted Directory in GitHub Enterprise Server leading to RCE
  39Monitor
• CVE-2021-22869Improper access control in GitHub Enterprise Server allows self-hosted runners to execute outside their control group
  39Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1const claims = jwt.verify(token, publicKey);

1const claims = jwt.verify(token, publicKey, {2  algorithms: ["RS256"],3  issuer: "https://id.example.com",4  audience: "portal",5});

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.