GibbonEdu Gibbon version 25.0.1 and before allows Arbitrary File Write because rubricsvisualisesaveAjax.phps does not require authentication. The endpoint accepts the img, path, and gibbonPersonID parameters. The img parameter is expected to be a base64 encoded image. If the path parameter is set, the defined path is used as the destination folder, concatenated with the absolute path of the installation directory. The content of the img parameter is base64 decoded and written to the defined file path. This allows creation of PHP files that permit Remote Code Execution (unauthenticated).