Themify Builder <= 7.6.1 - Missing Authorization to Authenticated (Contributor+) Post Duplication

The Themify Builder plugin for WordPress is vulnerable to unauthorized post duplication due to missing checks on the duplicate_page_ajaxify function in all versions up to, and including, 7.6.1. This makes it possible for authenticated attackers, with Contributor-level access and above, to duplicate and view private or draft posts created by other users that otherwise shouldn't be accessible to them.