Message-ID: <20060712.ips@psirt.cisco.com>
Date: Wed Jul 12 18:25:40 2006
From: psirt at cisco.com (Cisco Systems Product Security Incident Response Team)
Subject: Cisco Security Advisory: Cisco Intrusion
	Prevention System Malformed Packet Denial of Service

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Cisco Security Advisory: Cisco Intrusion Prevention System Malformed
Packet Denial of Service

Advisory ID: cisco-sa-20060712-ips

http://www.cisco.com/warp/public/707/cisco-sa-20060712-ips.shtml

Revision 1.0

For Public Release 2006 July 12 1600 UTC (GMT)

- ---------------------------------------------------------------------

Contents
========

    Summary
    Affected Products
    Details
    Impact
    Software Version and Fixes
    Workarounds
    Obtaining Fixed Software
    Exploitation and Public Announcements
    Status of this Notice: FINAL
    Distribution
    Revision History
    Cisco Security Procedures

- ---------------------------------------------------------------------

Summary
=======

Cisco Intrusion Prevention System (IPS) software version 5.1 is
vulnerable to a denial of service condition caused by a malformed
packet, which may result in an IPS device becoming inaccessible
remotely or via the console and fail to process packets. A power
reset is required to recover the IPS device. There are no workarounds
for this vulnerability.

Cisco has made free software available to address this vulnerability
for affected customers.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20060712-ips.shtml

Affected Products
=================

Vulnerable Products
+------------------

Cisco Intrusion Prevention System 42xx appliances running IPS
software versions 5.1(1), 5.1(1a), 5.1(1b), 5.1(1c), 5.1(1d), 5.1(1e)
or 5.1(p1).

IPS software versions 5.1(1a), 5.1(1b), 5.1(1c), 5.1(1d) and 5.1(1e)
are repackaged versions of 5.1(1) created to fix various installation
problems. All 5.1(1) patch versions report 5.1(1) as the installed
version.

Note: Some IDS/IPS appliances shipped before IPS software version 5.0
was available and have model numbers starting with IDS, not IPS.

The following 42xx appliances are potentially affected.

  * IDS-4235
  * IPS-4240
  * IDS-4250-SX
  * IDS-4250-TX
  * IDS-4250-XL (4250 with XL accelerator card)
  * IPS-4255

Products Confirmed Not Vulnerable
+--------------------------------

All devices running Cisco Intrusion Detection Systems (IDS) software
versions 4.x or IPS versions 5.0(x).

Additionally, the following devices are not vulnerable even if
running IPS software versions 5.1(1), 5.1(1a), 5.1(1b), 5.1(1c), 5.1
(1d), 5.1(1e) or 5.1(1p1).

  * NM-CIDS
  * IDSM-2
  * ASA-SSM-AIP-10
  * ASA-SSM-AIP-20
  * IDS-4210
  * IDS-4215

The following devices do not support IPS software version 5.1 and are
not vulnerable.

  * IDS-4220
  * IDS-4230

To determine the version of software running an IPS device, log into
the IPS device using an SSH client and issue the command show version.

    sensor#show version 
    Application Partition: Cisco Intrusion
    Prevention System, Version 5.1(1p1)S215.0
    

Details
=======

Cisco Intrusion Prevention Systems (IPS) are a family of network
security devices that provide network based threat prevention
services. A vulnerability exists in the custom device driver for
Intel-based gigabit network adapters used to process packets received
by the sensing interfaces of certain IPS devices. A malformed IP
packet received on an Intel-based gigabit network adapter configured
for use as a sensing interface may result in the IPS device
experiencing a kernel panic. Affected IPS devices will cease
processing packets, producing alerts, performing automated actions
such as logging, and become inaccessible remotely or via the console.

If deployed as an inline device, the IPS will also stop forwarding
packets between interfaces and may cause a network outage. IPS
devices configured to use the auto-bypass feature will also fail to
forward packets. Attackers may use this vulnerability to disable an
IPS device to hide malicious activity. This vulnerability only
affects certain IPS devices configured to use Intel-based gigabit
network adapters as sensing interfaces. IPS devices configured to use
an Intel-based gigabit network adapter as a management interface are
not affected by this vulnerability. A power reset is required to
recover the IPS device.

This vulnerability is documented in Cisco bug ID CSCsd36590 ( 
registered customers only) .

Impact
======

Successful exploitation of the vulnerability may result in the
failure of an IPS device to operate as expected. Affected devices
will become inaccessible remotely or via the console and stop
processing packets. If deployed as an inline device, an IPS device
will stop forwarding packets, including devices configured to use the
auto-bypass feature. This may result in a network outage. A power
reset is required to recover the IPS device.

Software Version and Fixes
==========================

When considering software upgrades, also consult
http://www.cisco.com/go/psirt and any subsequent advisories to
determine exposure and a complete upgrade solution.

In all cases, customers should exercise caution to be certain the
devices to be upgraded contain sufficient memory and that current
hardware and software configurations will continue to be supported
properly by the new release. If the information is not clear, contact
the Cisco Technical Assistance Center ("TAC") or your contracted
maintenance provider for assistance.

This issue is fixed in IPS version 5.1(2) which is available for
download at http://www.cisco.com/pcgi-bin/tablebuild.pl/ips5

Workarounds
===========

There are no workarounds for this vulnerability.

Obtaining Fixed Software
========================

Cisco will make free software available to address this vulnerability
for affected customers. This advisory will be updated as fixed
software becomes available. Prior to deploying software, customers
should consult their maintenance provider or check the software for
feature set compatibility and known issues specific to their
environment.

Customers may only install and expect support for the feature sets
they have purchased. By installing, downloading, accessing or
otherwise using such software upgrades, customers agree to be bound by
the terms of Cisco's software license terms found at
http://www.cisco.com/public/sw-license-agreement.html, or as
otherwise set forth at Cisco.com Downloads at
http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Do not contact either "psirt@...co.com" or "security-alert@...co.com"
for software upgrades.

Customers with Service Contracts
+-------------------------------

Customers with contracts should obtain upgraded software through
their regular update channels. For most customers, this means that
upgrades should be obtained through the Software Center on Cisco's
worldwide website at http://www.cisco.com .

Customers using Third Party Support Organizations
+------------------------------------------------

Customers whose Cisco products are provided or maintained through
prior or existing agreement with third-party support organizations
such as Cisco Partners, authorized resellers, or service providers
should contact that support organization for guidance and assistance
with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix is dependent on specific
customer situations such as product mix, network topology, traffic
behavior, and organizational mission. Due to the variety of affected
products and releases, customers should consult with their service
provider or support organization to ensure any applied workaround or
fix is the most appropriate for use in the intended network before it
is deployed.

Customers without Service Contracts
+----------------------------------

Customers who purchase direct from Cisco but who do not hold a Cisco
service contract and customers who purchase through third-party
vendors but are unsuccessful at obtaining fixed software through
their point of sale should get their upgrades by contacting the Cisco
Technical Assistance Center (TAC). TAC contacts are as follows.

  * +1 800 553 2447 (toll free from within North America)
  * +1 408 526 7209 (toll call from anywhere in the world)
  * e-mail: tac@...co.com

Have your product serial number available and give the URL of this
notice as evidence of your entitlement to a free upgrade. Free
upgrades for non-contract customers must be requested through the
TAC.

Refer to http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml
for additional TAC contact information, including special localized
telephone numbers and instructions and e-mail addresses for use in
various languages.

Exploitation and Public Announcements
=====================================

The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.

Status of this Notice: FINAL
============================

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY
KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE
INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS
AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS
DOCUMENT AT ANY TIME.

A stand-alone copy or Paraphrase of the text of this document that
omits the distribution URL in the following section is an
uncontrolled copy, and may lack important information or contain
factual errors.

Distribution
============

This advisory is posted on Cisco's worldwide website at:

http://www.cisco.com/warp/public/707/cisco-sa-20060712-ips.shtml

In addition to worldwide web posting, a text version of this notice
is clear-signed with the Cisco PSIRT PGP key and is posted to the
following e-mail and Usenet news recipients.

  * cust-security-announce@...co.com
  * first-teams@...st.org
  * bugtraq@...urityfocus.com
  * vulnwatch@...nwatch.org
  * cisco@...t.colorado.edu
  * cisco-nsp@...k.nether.net
  * full-disclosure@...ts.grok.org.uk
  * comp.dcom.sys.cisco@...sgate.cisco.com

Future updates of this advisory, if any, will be placed on Cisco's
worldwide website, but may or may not be actively announced on
mailing lists or newsgroups. Users concerned about this problem are
encouraged to check the above URL for any updates.

Revision History
================

+---------------------------------------+
| Revision | 2006-July-12  | Initial    |
| 1.0      | 1600 UTC      | public     |
|          | (GMT)         | release    |
+---------------------------------------+

Cisco Security Procedures
=========================

Complete information on reporting security vulnerabilities in Cisco
products, obtaining assistance with security incidents, and
registering to receive security information from Cisco, is available
on Cisco's worldwide website at
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html.
This includes instructions for press inquiries regarding Cisco
security notices.  All Cisco security advisories are available at
http://www.cisco.com/go/psirt.

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