LifterLMS < 4.21.1 - Authenticated Stored XSS in Edit Profile

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