LifterLMS < 4.21.1 – Authenticated Stored XSS in Edit Profile | CVE 2021-24308

Description

The 'State' field of the Edit profile page of the plugin 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.

Proof of Concept

1- As a Lowest Privilege user go to the edit account page of the LMS (e.g https://example.com/my-courses/edit-account/)
2- Put Your XSS payload in State parameter and save your edits, such as "><script>alert(/XSS/)</script>
3- The XSS will be stored and triggered in the about section of the profile: (e.g  https://example.com/directory/[user_name]/)

(Note: WPScanTeam): The XSS will also be triggered in the admin dashboard when viewing the user details, for example https://example.com/wp-admin/admin.php?page=llms-reporting&tab=students&stab=information&student_id=2