Auth bypass in Github
CVE-2021-22861
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.
EPSS: 0.009 (56.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Github
- Github Enterprise Server — versions 2.20, 2.21, 2.22
Weakness classification (CWE)
References
- product-cna@github.com (x_refsource_MISC)
- product-cna@github.com (x_refsource_MISC)
- product-cna@github.com (x_refsource_MISC)
- product-cna@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-22861?
- CVE-2021-22861 is a medium-severity vulnerability in Github, classified under Improper Authorization. CVSS score: 6.5/10. Published 2021-03-03.
- How severe is CVE-2021-22861?
- Medium severity. CVSS v3 base score is 6.5 out of 10.