Salon Booking System < 10.31.11 - Subscriber+ Coupon Code Disclosure via Discounts REST Route

The Salon Booking System WordPress plugin before 10.31.11 does not restrict one of its REST API endpoints to salon staff, allowing any authenticated user, such as a subscriber, to retrieve every discount coupon configured on the site, including coupons the administrator has chosen to hide from customers, together with their amounts, validity dates and usage limits.