CVE-2021-24429

The Salon booking system WordPress plugin before 6.3.1 does not properly sanitise and escape the First Name field when booking an appointment, allowing low privilege users such as subscriber to set JavaScript in them, leading to a Stored Cross-Site Scripting (XSS) vulnerability. The Payload will then be triggered when an admin visits the "Calendar" page and the malicious script is executed in the admin context.

Source: CVE-2021-24429