The Event Tickets and Registration plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.18.1 via the tc-order-id parameter due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to view order details of orders they did not place, which includes ticket prices, user emails and order date.
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.