RunCMS XSS Vulnerability via User Agent

Title: RunCMS XSS Vulnerability via User Agent
Vendor: RunCMS
Product: RunCMS
Tested Version: 2.1
Threat Class: XSS
Severity: Medium
Remote: yes
Local: no
Discovered By: Andrei Rimsa Alvares

===== Description =====

RunCMS is prone to a XSS vulnerability by mangling the user-agent field on a http request to a script within
the forum module.

----- modules/forum/check.php -----
01: …
10: echo "BROWSER: ".$_SERVER['HTTP_USER_AGENT'];
----- modules/forum/check.php -----

===== Impact =====

Malicious java script code can be executed in the context of the affected web site.

===== Proof of Concept =====

wget --user-agent="

" http://target/modules/forum/check.php

===== Workaround =====

Remove the affected file form the system: modules/forum/check.php.

===== Disclosure Timeline =====

June, 16 2010 - Vendor notification.
June, 17 2010 - Vendor response confirming the bug.
July, 07 2010 - Public disclosure.

===== References =====

http://www.runcms.org

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