CVE-2021-22864: Unsafe configuration options in GitHub Pages leading to remote code execution on GitHub Enterprise Server
A remote code execution vulnerability was identified in GitHub Enterprise Server that could be exploited when building a GitHub Pages site. User-controlled configuration options used by GitHub Pages were not sufficiently restricted and made it possible to override environment variables leading to code execution on the GitHub Enterprise Server instance. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.0.3 and was fixed in 3.0.3, 2.22.9, and 2.21.17. This vulnerability was reported via the GitHub Bug Bounty program.
Affected Software
Event History
Frequently Asked Questions
What is CVE-2021-22864?
CVE-2021-22864 is a remote code execution vulnerability in GitHub Enterprise Server that can be exploited when building a GitHub Pages site.
How does CVE-2021-22864 impact GitHub Enterprise Server?
CVE-2021-22864 allows attackers to execute remote code on the affected GitHub Enterprise Server instances.
What is the severity of CVE-2021-22864?
CVE-2021-22864 has a severity rating of 8.8 (high).
Which versions of GitHub Enterprise Server are affected by CVE-2021-22864?
GitHub Enterprise Server versions 2.21.0 to 2.21.17, 2.22.0 to 2.22.9, and 3.0.0 to 3.0.3 are affected by CVE-2021-22864.
How can I fix CVE-2021-22864?
To fix CVE-2021-22864, update GitHub Enterprise Server to a version that is not affected by the vulnerability (2.21.18 or later, 2.22.10 or later, or 3.0.4 or later). Additionally, ensure that user-controlled configuration options for GitHub Pages are properly restricted.