The HAPPY – Helpdesk Support Ticket System plugin for WordPress is vulnerable to authorization bypass due to a missing capability check on the 'submit_form_reply' AJAX action in all versions up to, and including, 1.0.9. This makes it possible for authenticated attackers, with Subscriber-level access and above, to submit replies to arbitrary support tickets by manipulating the 'happy_topic_id' parameter, regardless of whether they are the ticket owner or have been assigned to the ticket.
CWE-862