Jenkins Blue Ocean Plugin cross-site request forgery vulnerability

Jenkins Blue Ocean Plugin 1.27.5 and earlier does not require POST requests for an HTTP endpoint, resulting in a cross-site request forgery (CSRF) vulnerability.

This vulnerability allows attackers to connect to an attacker-specified URL, capturing GitHub credentials associated with an attacker-specified job.

This issue is due to an incomplete fix of SECURITY-2502.

Blue Ocean Plugin 1.27.5.1 uses the configured SCM URL, instead of a user-specified URL provided as a parameter to the HTTP endpoint.