The 2.21.6 update is a security update, fixing a few critical security issues. Since it is a critical security patch, we are applying the patch off-schedule as soon as possible.
- CRITICAL: A remote code execution vulnerability was identified in GitHub Pages that could be exploited when building a GitHub Pages site. User-controlled configuration of the underlying parsers used by GitHub Pages were not sufficiently restricted and made it possible to execute commands 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. The underlying issues contributing to this vulnerability were identified both internally and through the GitHub Security Bug Bounty program. We have issued CVE-2020-10518.
- MEDIUM: An improper access control vulnerability was identified that allowed authenticated users of the instance to determine the names of unauthorized private repositories given their numerical IDs. This vulnerability did not allow unauthorized access to any repository content besides the name. This vulnerability affected all versions of GitHub Enterprise Server prior to 2.22 and has been assigned CVE-2020-10517. The vulnerability was reported via the GitHub Bug Bounty program.
- Packages have been updated to the latest security versions.
We will be applying the patch at 5:00 PM EST on August 27th.