The SupportCandy – Helpdesk & Customer Support Ticket System plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.3.0 via file upload due to missing validation on a user controlled key. This makes it possible for authenticated attackers to download attachments for support tickets that don't belong to them. If an admin enables tickets for guests, this can be exploited by unauthenticated attackers.