TrueBooker <= 1.2.3 - Missing Authorization to Unauthenticated Arbitrary Password Reset via 'tbab-userid'

The TrueBooker – Appointment Booking and Scheduler System plugin for WordPress is vulnerable to account takeover via improper password reset validation in all versions up to, and including, 1.2.3. This is due to the plugin not properly validating a user's identity before resetting their password. This makes it possible for unauthenticated attackers to reset the password of arbitrary user accounts, including administrators, and gain access to those accounts.