cybsecApps.txt

`CYBSEC S.A.  
www.cybsec.com  
  
Advisory Name: Multiple Vendor Web Vulnerability Scanner Arbitrary  
============= Script Injection Vulnerability  
  
Vulnerability Class: Script Injection  
====================  
  
Release Date: 09.01.2005  
=============  
  
Affected Applications:  
======================  
* N-Stealth Commercial Edition < 5.8.0.38  
* N-Stealth Free Edition < 5.8.1.03  
* Nikto <= 1.35  
  
Affected Platforms:  
===================  
* Platform-Independent: Tested on Windows 2000 and Debian GNU/Linux  
  
Local / Remote: Remote  
===============  
  
Severity: Medium  
=========  
  
Author: Mariano Nuñez Di Croce  
=======  
  
Vendor Status: Confirmed. Update released.  
==============  
  
Reference to Vulnerability Disclosure Policy:  
=============================================  
http://www.cybsec.com/vulnerability_policy.pdf  
  
Overview:  
=========  
  
"N-Stealth is a vulnerability-assessment product that scans web servers  
to identify security problems and weaknesses that may allow an attacker  
to gain privileged access.The software comes with an extensive database  
of over 30,000 vulnerabilities and exploits".  
  
"Nikto is an Open Source (GPL) web server scanner which performs  
comprehensive tests against web servers for multiple items, including  
over 3200 potentially dangerous files/CGIs, versions on over 625  
servers, and version specific problems on over 230 servers".  
  
Vulnerability Description:  
==========================  
  
A bug exists in the way multiple web vulnerability scanners process  
responses received from the host being scanned.  
  
If the target host has modified the "Server" field of the HTTP Response  
headers, including DHTML code in it, this code will be executed by the  
browser when the HTML report is generated.  
  
It's important to emphasize that this code will be executed under "My  
Computer" Security Zone when viewed with IE.  
  
Proof of Concept (using mod_security):  
--------------------------------------  
  
SecServerSignature "Microsoft-IIS/5.0<script>alert('test')</script>"  
  
Besides, in N-Stealth main dialog, the Server header is displayed up to  
its 54th character. So, with the correct blank padding after the fake  
version banner, the DHTML code won't be noticed in this window.  
  
Solutions:  
==========  
  
N-Stealth vendor has released an update that fixes the vulnerability.  
Update can be downloaded at http://www.nstalker.com.  
  
Nikto vendor has released an update that warns the user of dangers in  
viewing HTML reports.  
Update can be downloaded at http://www.cirt.net.  
  
Vendor Response:  
================  
  
07.26.2005 - Vendors Notified.  
07.26.2005 - Nikto Vendor Confirmed Vulnerability.  
07.26.2005 - Nikto Vendor Supplied Update.  
08.15.2005 - N-Stealth Vendor Confirmed Vulnerability.  
08.25.2005 - N-Stealth Vendor Supplied Update.  
09.01.2005 - Vulnerability Public Disclosure.  
  
Special Thanks: Leandro Meiners.  
===============  
  
Contact Information:  
====================  
  
For more information regarding the vulnerability feel free to contact  
the author at mnunez {at} cybsec.com.  
  
For more information regarding CYBSEC: www.cybsec.com  
  
(c) 2005 - CYBSEC S.A. Security Systems  
`