WP Courses LMS < 2.0.44 - Authenticated Stored XSS via Video Embed Code

Description

The plugin does not sanitise its Video Embed Code, allowing malicious code to be injected in it by high privilege users, even when the unfiltered_html capability is disallowed, which could lead to Stored Cross-Site Scripting issues

Proof of Concept

1. On the dashboard, navigate to WP Courses > Courses > Add New > Video Embed Code (iframe) (in the Post settings), inject with <iframe> XSS payload, such as <iframe src="javascript:alert(document.cookie)"></iframe>;  <iframe src="javascript:%61%6c%65%72%74%28%64%6f%63%75%6d%65%6e%74%2e%63%6f%6f%6b%69%65%29"></iframe>

2. Click Update, and to trigger XSS payload, open URL path of course