Cross-site request forgery (CSRF) vulnerability in attachment.cgi in Bugzilla 2.x, 3.x, and 4.0.x before 4.0.11; 4.1.x and 4.2.x before 4.2.7; and 4.3.x and 4.4.x before 4.4.1 allows remote attackers to hijack the authentication of arbitrary users for requests that commit an attachment change via an update action.