The Appointment Hour Booking plugin for WordPress is vulnerable to CAPTCHA bypass in versions up to, and including, 1.3.72. This is due to the use of insufficiently strong hashing algorithm on the CAPTCHA secret that is also displayed to the user via a cookie.

The Appointment Hour Booking Plugin for WordPress is vulnerable to CSV Injection in versions up to, and including, 1.3.72. This makes it possible for unauthenticated attackers to embed untrusted input into content during booking creation that may be exported as a CSV file when a site's administrator exports booking details. This can result in code execution when these files are downloaded and opened on a local system with a vulnerable configuration.

The Appointment Hour Booking plugin for WordPress is vulnerable to iFrame Injection via the ‘email’ or general field parameters in versions up to, and including, 1.3.72 due to insufficient input sanitization and output escaping that makes injecting iFrame tags possible. This makes it possible for unauthenticated attackers to inject iFrames when submitting a booking that will execute whenever a user accesses the injected booking details page.