Salon Booking System < 6.3.1 – Unauthenticated Stored Cross-Site Scripting (XSS) | CVE 2021-24429

Description

The plugin 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.

Proof of Concept

When booking an appointment, either as unauthenticated or any authenticated user, put the following payload in the First Name field: test" onfocus=alert('XSS')

The payload will be triggered when an admin will access the appointment via the 'Calendar' page


Edit (WPScanTeam): Payload w/o user interaction other than accessing the calendar page: " style="animation-name:rotation" onanimationstart="alert(/XSS/)//