An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios. It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program.
A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration identifier, an attacker could overwrite or replace a victim’s migration archive, potentially causing victims to download attacker-controlled repository data during migration restores or automated imports. An attacker would require authentication to the victim's GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.19.2, 3.18.5, 3.17.11, 3.16.14, 3.15.18, 3.14.23. This vulnerability was reported via the GitHub Bug Bounty program.
An URL redirection vulnerability was identified in GitHub Enterprise Server that allowed attacker-controlled redirects to leak sensitive authorization tokens. The repository_pages API insecurely followed HTTP redirects when fetching artifact URLs, preserving the authorization header containing a privileged JWT. An authenticated user could redirect these requests to an attacker-controlled domain, exfiltrate the Actions.ManageOrgs JWT, and leverage it for potential remote code execution. Attackers would require access to the target GitHub Enterprise Server instance and the ability to exploit a legacy redirect to an attacker-controlled domain. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.19 and was fixed in versions 3.19.2, 3.18.4, 3.17.10, 3.16.13, 3.15.17, and 3.14.22. This vulnerability was reported via the GitHub Bug Bounty program.