F5 FirePass SSL VPN Unauthenticated 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: www.f5.com

found: 2012-06-01

by: S. Viehböck

SEC Consult Vulnerability Lab



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: 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


As opposed to some information on the Internet (e.g.

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.




Apply HF-70-7 or HF-388207-1. For detailed information see:


Patch information is also available at:





No workaround available.


Advisory URL:





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A-1190 Vienna


Tel.: +43 / 1 / 890 30 43 - 0

Fax.: +43 / 1 / 890 30 43 - 25

Mail: research at sec-consult dot com



EOF S. Viehböck / @2012