Erident Custom Login & Dashboard 3.4-3.4.1 - Stored Cross-Site Scripting (XSS)

The Erident Custom Login and Dashboard plugin exposes a call to the update_option method, when a specific POST field is posted to the plugins setting screen. No CSRF token is used, and as such if an Administrative user can be tricked into visiting a site with a malicious form, it is possible to trigger a Stored Cross-Site Scripting attack in the admin dashboard by utilising this unsafe method call. The vulnerable method call is located on line 312 of erident-custom-login-and-dashboard/er-custom-login.php.

PoC