The Post Duplicator plugin for WordPress is vulnerable to Information Exposure in all versions up to, and including, 2.36 via the mtphr_duplicate_post() due to insufficient restrictions on which posts can be duplicated. This makes it possible for authenticated attackers, with Contributor-level access and above, to extract data from password protected, private, or draft posts that they should not have access to by duplicating the post.
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.