XenForo before 2.2.14 allows Directory Traversal (with write access) by an authenticated user who has permissions to administer styles, and uses a ZIP archive for Styles Import.
In XenForo through 2.2.7, a threat actor with access to the admin panel can create a new Advertisement via the Advertising function, and save an XSS payload in the body of the HTML document. This payload will execute globally on the client side.