WordPress is a free and open-source content management system (CMS) based on PHP and MySQL. Stored XSS exists in the Appointment Booking Calendar plugin before 1.3.35 for WordPress. In the cpabc_appointments.php file, the Calendar Name input could allow attackers to inject arbitrary JavaScript or HTML.This rule supports to defend the A6: Vulnerable and Outdated Components and A3: Injection of OWASP Top 10 - 2021. Other reference:None