Media Sync <= 1.4.9 - Authenticated (Author+) Path Traversal via 'sub_dir' and 'media_items' Parameters

The Media Sync plugin for WordPress is vulnerable to Path Traversal in all versions up to, and including, 1.4.9 via the 'sub_dir' and 'media_items' parameters. This is due to insufficient validation of user-supplied file paths, which are not checked for directory traversal sequences or restricted to the intended uploads directory. This makes it possible for authenticated attackers, with Author-level access and above, to perform actions on files outside of the originally intended directory.