Path traversal in GitHub Enterprise Server leading to remote code execution in GitHub Pages

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 instance. This vulnerability was fixed in versions 3.3.17, 3.4.12, 3.5.9, 3.6.5 and 3.7.2. This vulnerability was reported via the GitHub Bug Bounty program.