The Total Book Project <= 1.0 - Insecure Direct Object Reference to Authenticated (Contributor+) Book Manipulation

The The Total Book Project plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.0 via several functions due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Contributor-level access and above, to perform several actions like moving/deleting/creating chapters in books that do not belong to them.