Jenkins Google Compute Engine Plugin has incorrect permission checks

Jenkins Google Compute Engine Plugin 4.550.vb_327fca_3db_11 and earlier does not correctly perform permission checks in multiple HTTP endpoints. This allows attackers with global Item/Configure permission (while lacking Item/Configure permission on any particular job) to do the following:

• Enumerate system-scoped credentials IDs of credentials stored in Jenkins. Those can be used as part of an attack to capture the credentials using another vulnerability.

• Connect to Google Cloud Platform using attacker-specified credentials IDs obtained through another method, to obtain information about existing projects.

Google Compute Engine Plugin 4.551.v5a_4dc98f6962 requires Overall/Administer permission for the affected HTTP endpoints.