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.

A missing permission check in Jenkins Gearman Plugin in the GearmanPluginConfig#doTestConnection form validation method allows attackers with Overall/Read permission to initiate a connection to an attacker-specified server.