The Appointment Booking Plugin WordPress plugin before 5.6.8 does not restrict which booking fields an unauthenticated visitor can set through its public booking funnel, allowing an unauthenticated user to assign a privileged booking field such as the approval status and thereby bypass the sites booking approval workflow.
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
Access control involves the use of several protection mechanisms such as:
When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses: