The Tickera – Sell Tickets & Manage Events plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the 'wp_ajax_change_ticket_status' AJAX endpoint in all versions up to, and including, 3.5.6.4. This makes it possible for authenticated attackers, with Subscriber-level access and above, to update post/event statuses.
https://plugins.trac.wordpress.org/changeset/3422813
https://plugins.trac.wordpress.org/browser/tickera-event-ticketing-system/trunk/tickera.php#L3903