Lifterlms Cross-site Scripting

The LifterLMS PayPal WordPress plugin before 1.4.0 does not sanitise and escape some parameters from the payment confirmation page before outputting them back in the page, leading to a Reflected Cross-Site Scripting issue (2022-05-02, CVE-2022-1250)

The 'State' field of the Edit profile page of the LMS by LifterLMS – Online Course, Membership & Learning Management System Plugin for WordPress plugin before 4.21.1 is not properly sanitised when output in the About section of the profile page, leading to a stored Cross-Site Scripting issue. This could allow low privilege users (such as students) to elevate their privilege via an XSS attack when an admin will view their profile. (2021-05-24, CVE-2021-24308)

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>