RTMKit < 2.0.8 - Authenticated (Contributor+) Missing Authorization to Arbitrary Form Submission Access via 'entries_id' Parameter

Description

The RTMKit plugin for WordPress is vulnerable to Incorrect Authorization in all versions up to, and including, 2.0.7 This is due to the get_submission_content AJAX endpoint lacking a capability check to verify that a user has permission to access the requested form submission data. This makes it possible for authenticated attackers, with Contributor-level access and above, to view arbitrary form submissions from other users by iterating the entries_id parameter.