Frontend Post Submission Manager Lite <= 1.2.5 - Missing Authorization to Unauthenticated Arbitrary Post Modification

The Frontend Post Submission Manager Lite plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 1.2.5. This is due to missing authorization checks on the post update functionality in the fpsml_form_process AJAX action. This makes it possible for unauthenticated attackers to modify arbitrary posts by providing a post_id parameter via the guest posting form, allowing them to change post titles, content, excerpts, and remove post authors.