Appointment Hour Booking <= 1.3.72 - CAPTCHA Bypass

Guessable CAPTCHA
CVE CVE-2022-4036
CVSS 5.3 (Medium)
Publicly Published November 29, 2022
Last Updated January 22, 2024
Researchers Luca Greeb
Andreas Krüger


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.



Vulnerability Details for Appointment Hour Booking – WordPress Booking Plugin

Software Type Plugin
Software Slug appointment-hour-booking (view on
Patched? Yes
Remediation Update to version 1.3.73, or a newer patched version
Affected Version
  • <= 1.3.72
Patched Version
  • 1.3.73

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