Details

Application: Usernoise ( http://usernoise.karevn.com/ )
Version: 3.7.8 (probably earlier versions as well)
Type: Wordpress plugin
Developer: Nikolay Karev ( http://karevn.com/ - http://profiles.wordpress.org/karevn/)
Vulnerability: Unauthorized persistent cross-site scripting

Description

Usernoise is a "just works" modal contact / feedback form. It became responsive starting from 3.5 release. You will not need to change even a line of code in your site.

Vulnerability

The summary field is vulnerable to persistent cross site scripting, and the affected area is the Wordpress admin dashboard. The reason why this vulnerability exists is because the user input is not being properly handled when a feedback is submitted. It accepts any type of arbitrary code, including JavaScript, and when the content is displayed in the feedback section in the dashboard, all JavaScript code is executed causing a sever vulnerability with administrators as the target.

Proof of Concept

<script>document.documentElement.innerHTML='RogueCoder was here';</script>
Well done! Website looks great<script>console.log('RogueCoder was here');</script>

Solution

Upgrade to plugin version 3.7.9

Timeline

2013-07-15 - Informed developer through plugin section on wordpress.org
2013-07-16 - Informed developer through email
2013-07-17 - Fix released