Path traversal in GitHub Enterprise Server leading to remote code execution

Summary

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed remote code execution when building a GitHub Pages site. 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 versions 3.8 and was fixed in versions 3.7.7, 3.6.10, 3.5.14, and 3.4.17. This vulnerability was reported via the GitHub Bug Bounty program.