Everest Forms (Pro) <= 1.9.4 - Unauthenticated Path Traversal to Arbitrary File Deletion

The Everest Forms (Pro) plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the delete_entry_files() function in all versions up to, and including, 1.9.4. This makes it possible for unauthenticated attackers to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php). The vulnerability requires an admin to trigger the deletion via deletion of a form entry and cannot be carried out by the attacker alone.