Improper access control in GitHub Enterprise Server leading to unauthorized write access to forkable repositories
Vulnerability Description
An improper access control vulnerability was identified in GitHub Enterprise Server that allowed authenticated users of the instance to gain write access to unauthorized repositories via specifically crafted pull requests and REST API requests. An attacker would need to be able to fork the targeted repository, a setting that is disabled by default for organization owned private repositories. Branch protections such as required pull request reviews or status checks would prevent unauthorized commits from being merged without further review or validation. This vulnerability affected all versions of GitHub Enterprise Server since 2.4.21 and was fixed in versions 2.20.24, 2.21.15, 2.22.7 and 3.0.1. This vulnerability was reported via the GitHub Bug Bounty program.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
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Credits & Attribution
The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:
- Teddy Katz
References
- https://docs.github.com/en/enterprise-server%402.20/admin/release-notes#2.20.24
- https://docs.github.com/en/enterprise-server%402.21/admin/release-notes#2.21.15
- https://docs.github.com/en/enterprise-server%402.22/admin/release-notes#2.22.7
- https://docs.github.com/en/enterprise-server%403.0/admin/release-notes#3.0.1
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