The Free Booking Plugin for Hotels, Restaurants and Car Rentals – eaSYNC Booking plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.3.21 via the 'view_request_details' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to view the details of any booking request. The vulnerability was partially patched in versions 1.3.18 and 1.3.21.
The Free Booking Plugin for Hotels, Restaurants and Car Rentals WordPress plugin before 1.3.15 does not have CSRF check in place when updating its settings, which could allow attackers to make a logged in subscriber change them via a CSRF attack