Multiple cross-site scripting (XSS) vulnerabilities in Six Apart Movable Type (MT) before 4.23 allow remote attackers to inject arbitrary web script or HTML via a (1) MTEntryAuthorUsername, (2) MTAuthorDisplayName, (3) MTEntryAuthorDisplayName, or (4) MTCommenterName field in a Profile View template; a (5) listing screen or (6) edit screen in the CMS app; (7) a TrackBack title, related to the HTML sanitization library; or (8) a user archive name (aka archive title) on a published Community Blog template.