Favicon By Realfavicongenerator Cross-site Scripting

The Favicon by RealFaviconGenerator WordPress plugin before 1.3.23 does not properly sanitise and escape the json_result_url parameter before outputting it back in the Favicon admin dashboard, leading to a Reflected Cross-Site Scripting issue (2022-04-11, CVE-2022-0471)

The Favicon by RealFaviconGenerator WordPress plugin through 1.3.20 does not sanitise or escape one of its parameter before outputting it back in the response, leading to a Reflected Cross-Site Scripting (XSS) which is executed in the context of a logged administrator. (2021-08-30, CVE-2021-24437)

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>