A Cross-Site Request Forgery vulnerability in GitHub Enterprise Server allowed write operations on a victim-owned repository by exploiting incorrect request types. A mitigating factor is that the attacker would have to be a trusted GitHub Enterprise Server user, and the victim would have to visit a tag in the attacker's fork of their own repository. vulnerability affected all versions of GitHub Enterprise Server prior 3.14 and was fixed in version 3.13.1, 3.12.6, 3.11.12, 3.10.14, and 3.9.17. This vulnerability was reported via the GitHub Bug Bounty program.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.