SA-20071101-0.txt

`SEC Consult Security Advisory < 20071101-0 >  
=====================================================================================  
title: Multiple vulnerabilities in SonicWALL SSL-VPN  
Client  
* Deletion of arbitrary files on the client  
* Arbitrary code execution thru various buffer  
overflows  
program: SonicWALL SSL-VPN  
vulnerable version: SonicWALL SSL-VPN 1.3.0.3  
WebCacheCleaner ActiveX Control 1.3.0.3  
NeLaunchCtrl ActiveX Control 2.1.0.49  
homepage: www.sonicwall.com  
found: 04-23-2007  
by: lofi42  
perm. link: http://www.sec-consult.com/303.html  
=====================================================================================  
  
Vendor description:  
---------------  
  
SonicWALL SSL-VPN solutions can be configured to provide users with  
easy-to-use, secure and clientless remote access to a broad range of  
resources on the corporate network.  
  
  
Vulnerabilty overview:  
---------------  
  
The SonicWALL SSL-VPN solution comes with various ActiveX Controls which  
allows users to access the VPN with Internet Explorer. These controls  
contain various vulnerabilities. An attacker could take control of the  
affected clients by placing exploit code on a webserver. He would then  
have to entice VPN users to visit the website, e.g. by conducting a  
phishing attack. Various other attack vectors exist (DNS redirection,  
owning an intranet website, ...).  
  
  
Vulnerability details:  
---------------   
  
1.) Deletion of arbitrary files  
  
The WebCacheCleaner ActiveX Control provides the method FileDelete()  
which, working as advertised, allows the attacker to delete arbitrary  
files on the client.  
  
  
=== Proof of Concept 1 (VBScript) ===  
  
dim o  
Set o = CreateObject("MLWebCacheCleaner.WebCacheCleaner.1")  
o.FileDelete("c:\bla\bla")  
  
=== /Proof of Concept 1 ===  
  
  
2.) Multiple buffer overflows  
  
A stack-based buffer overflow exists in the AddRouteEntry() method of  
the NELaunchCtrl ActiveX Control. Specifically, the second paramter to  
this method is copied to into a stack buffer without length validiation.  
Use the following to make the process jump into UVWX-land:  
  
o.AddRouteEntry ("", "ABCDEFGHIJKLMNOPQRSTUVWX");  
  
  
Additionally, the following properties suffer from Unicode overflows:  
  
serverAddress  
sessionId  
clientIPLower  
clientIPHigher  
userName  
domainName  
dnsSuffix  
  
  
=== Proof of Concept 2 ===  
  
A code execution exploit will not be released to the public. However, as  
exploitation is trivial, we strongly advise to perform an update.  
  
  
vendor status:  
---------------  
vendor notified: 2007-05-21  
vendor response: 2007-05-21  
patch available: September 2007  
  
The issues have been fixed with version 2.1 of SSL-VPN 200 and version  
2.5 of SSL-VPN 2000/4000.  
  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
* The vulnerabilities described above have been purchased by   
SEC Consult from an independent security researcher.  
In the research bonus programme, SEC Consult is looking for security   
vulnerabilities in common software products. For more information,  
contact research [at] sec-consult [dot] com  
  
EOF Bernhard Mueller / SEC Consult  
  
  
`