MasterStudy LMS WordPress Plugin – for Online Courses and Education <= 3.7.14 - Insecure Direct Object Reference to Authenticated (Instructor+) Arbitrary Attachment Deletion

The MasterStudy LMS WordPress Plugin – for Online Courses and Education plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.7.14. This is due to the `stm_lms_delete_cover()` function lacking ownership validation on the `file_id` parameter before passing it to `wp_delete_attachment()`. This makes it possible for authenticated attackers, with Instructor-level access and above, to delete arbitrary attachments belonging to any user by enumerating sequential attachment IDs.