iDefense Security Advisory 03.01.11
http://labs.idefense.com/intelligence/vulnerabilities/
Mar 01, 2011

I. BACKGROUND

The Alcatel-Lucent OmniPCX Enterprise Communication Server (CS) is a
communication server platform that provides multimedia call processing
for both Alcatel-Lucent and third-party clients/phones. For more
information, see the vendor's site found at the following link.

http://enterprise.alcatel-lucent.com/?product=OmniPCXEnterprise&page=overview

II. DESCRIPTION

Remote exploitation of a stack based buffer overflow vulnerability in
Alcatel-Lucent's OmniPCX Enterprise Communication Server could allow an
attacker to execute arbitrary code with the privileges of the affected
service.

The Alcatel-Lucent OmniPCX Enterprise Communication Server (CS) is used
to process, manage, and log traditional as well as VOIP based
telephony. Part of the maintenance functionality consists of a web
based administrative interface consisting of various CGI and PHP based
scripts. The vulnerability occurs in the handling of multiple CGI
applications that make up the web application.

The vulnerability occurs when parsing certain HTTP headers. String based
data from the HTTP request is improperly validated, which can result in
a trivial stack based buffer overflow.

III. ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary
code with the privileges of the affected service, usually the user
'mtcl'. This user is not equivalent to root, but does have access to
most of the files used for managing the OXE system.

The OXE environment consists of a custom Linux distribution. It doesn't
employ any of the modern exploit mitigation defenses like ASLR or NX.
As such, this vulnerability is trivial to exploit reliably.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in OmniPCX
Enterprise version 8. Alcatel-Lucent has stated that the following
versions are vulnerable:

OmniPCX Enterprise: all versions prior to R9.0

OmniPCX Enterprise release R9.0: all versions prior to patch H1.301.50
(excluded).The following versions are not vulnerable:

OmniPCX Enterprise release R9.0 H1.301.50 and more recent.

OmniPCX Enterprise release R9.1 and later.

V. WORKAROUND

The embedded web server can be deactivated by using the netadmin
command. The steps to perform this are documented in the following
location of the administration guide: 11.Security > 11.9.Web server
configuration > 11.9.1.Deactivate the Web server, then apply your
change.

< br /> This will remove all functionality provided by the web server,
but has no impact on the normal system operation.

VI. VENDOR RESPONSE

An official fix is available for customers through Alcatel-Lucent
Business Partners since mid january on their support website. An
Alcatel-Lucent security advisory is available on

www.alcatel-lucent.com/security/psirt

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2011-0344 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

10/04/2010  Initial Vendor Notification
11/03/2010  Initial Vendor Reply
03/01/2011  Coordinated Public Disclosure

IX. CREDIT

This vulnerability was reported to iDefense by Anonymous.

Get paid for vulnerability research
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X. LEGAL NOTICES

Copyright © 2011 Verisign

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
 There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct,
indirect, or consequential loss or damage arising from use of, or
reliance on, this information.