The Guest Support – Complete customer support ticket system for WordPress plugin for WordPress is vulnerable to unauthorized loss of data due to a missing capability check on the 'deleteMassTickets' function in all versions up to, and including, 1.2.2. This makes it possible for unauthenticated attackers to delete arbitrary support tickets.
https://plugins.trac.wordpress.org/changeset/3322664/
https://plugins.trac.wordpress.org/browser/guest-support/trunk/includes/library/ajax.php#L133