Appointment Hour Booking Cross-site Scripting

The Appointment Hour Booking plugin for WordPress is vulnerable to iFrame Injection via the ‘email’ or general field parameters in versions up to, and including, 1.3.72 due to insufficient input sanitization and output escaping that makes injecting iFrame tags possible. This makes it possible for unauthenticated attackers to inject iFrames when submitting a booking that will execute whenever a user accesses the injected booking details page. (2022-11-29, CVE-2022-4035)

The Appointment Hour Booking WordPress plugin before 1.3.56 does not sanitise and escape a settings of its Calendar fields, which could allow high privilege users to perform Cross-Site Scripting attacks even when the unfiltered_html is disallowed. (2022-06-13, CVE-2022-1710)

The Appointment Hour Booking WordPress plugin before 1.3.17 does not properly sanitize values used when creating new calendars. (2021-10-11, CVE-2021-24712)

The Appointment Hour Booking WordPress plugin before 1.3.16 does not escape some of the Calendar Form settings, allowing high privilege users to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed. (2021-10-04, CVE-2021-24673)

The Appointment Hour Booking plugin 1.1.44 for WordPress allows XSS via the E-mail field, as demonstrated by email_1. (2019-07-11, CVE-2019-13505)

Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.

The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:

https://server.com/confirmation?message=Transaction+Complete

what results in:

<span>Confirmation: Transaction Complete</span>

In that case the message can be modified to become a valid Javascript code, e.g.:

https://server.com/confirmation?message=<script>dangerous javascript code here</script>

and it will be executed locally by the user's browser with full access to the user's personal application/browser data:

<span>Confirmation: <script>dangerous javascript code here</script></span>