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.

Cross-site scripting (XSS) vulnerability in Gitweb 1.7.3.3 and earlier allows remote attackers to inject arbitrary web script or HTML via the (1) f and (2) fp parameters.

git-daemon in git 1.4.4.5 through 1.6.3 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a request containing extra unrecognized arguments.

gitweb/gitweb.perl in gitweb in Git 1.6.x before 1.6.0.6, 1.5.6.x before 1.5.6.6, 1.5.5.x before 1.5.5.6, 1.5.4.x before 1.5.4.7, and other versions after 1.4.3 allows local repository owners to execute arbitrary commands by modifying the diff.external configuration variable and executing a crafted gitweb query.