The Get Post Content Shortcode plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 0.4 via the 'post-content' shortcode due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the content of password-protected, private, draft, and pending posts.
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.