Cross-site request forgery (CSRF) vulnerability in SKYARC MTCMS before 5.252, and the MultiFileUploader 0.44 and earlier, DuplicateEntry 1.2 and earlier, MailPack 1.741 and earlier, and AutoTagging 0.08 and earlier plugins for Movable Type, allows remote attackers to hijack the authentication of arbitrary users for requests that modify data.