Login Logout Menu < 1.4.0 - Contributor+ Stored XSS in Shortcode

The plugin does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.

PoC

Exploit shortcode: [login_logout_menu__login_logout_link login_logout_class=‘" onmouseover=“alert(1)”’]