The The Ultimate WordPress Toolkit – WP Extended plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.0.8 via the duplicate_post function due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Contributor-level access and above, to duplicate posts written by other authors including admins. This includes the ability to duplicate password-protected posts, which reveals their contents.
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.