Git Plugin connects to a user-specified Git repository as part of form validation. An attacker with no direct access to Jenkins but able to guess at a username/password credentials ID could trick a developer with job configuration permissions into following a link with a maliciously crafted Jenkins URL which would result in the Jenkins Git client sending the username and password to an attacker-controlled server.

Jenkins Proxmox Plugin 0.5.0 and earlier stores the Proxmox Datacenter password unencrypted in the global config.xml file on the Jenkins controller where it can be viewed by users with access to the Jenkins controller file system.