The WP User Manager plugin for WordPress is vulnerable to Arbitrary File Deletion in all versions up to, and including, 2.9.12. This is due to insufficient validation of user-supplied file paths in the profile update functionality combined with improper handling of array inputs by PHP's filter_input() function. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete arbitrary files on the server via the 'current_user_avatar' parameter in a two-stage attack which can make remote code execution possible. This only affects sites with the custom avatar setting enabled.