The Waiting: One-click countdowns plugin for WordPress is vulnerable to authorization bypass due to missing capability checks on its AJAX calls in versions up to, and including, 0.6.2. This makes it possible for authenticated attackers, with subscriber-level permissions and above, to create and delete countdowns as well as manipulate other plugin settings.
https://plugins.trac.wordpress.org/browser/waiting/trunk/waiting.php?rev=2826039