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