Cisco Security Advisory: Cisco IOS Software NAT Skinny Call Control Protocol Vulnerability

24 Mar 2010

Skinny Client Control Protocol (SCCP) crafted messages may cause a
Cisco IOS device that is configured with the Network Address
Translation (NAT) SCCP Fragmentation Support feature to reload.

Cisco has released free software updates that address this
vulnerability. A workaround that mitigates this vulnerability is
available.

This advisory is posted at:

http://www.cisco.com/warp/public/707/cisco-sa-20100324-sccp.shtml

Note: The March 24, 2010, Cisco IOS Software Security Advisory
bundled publication includes seven Security Advisories. All the
advisories address vulnerabilities in Cisco IOS Software. Each
advisory lists the releases that correct the vulnerability or
vulnerabilities detailed in the advisory. The table at the following
URL lists releases that correct all Cisco IOS Software
vulnerabilities that have been published on March 24, 2010, or
earlier:

http://www.cisco.com/warp/public/707/cisco-sa-20100324-bundle.shtml

Individual publication links are in "Cisco Event Response: Semiannual
Cisco IOS Software Security Advisory Bundled Publication" at the
following link:

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_mar10.html

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

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

This security advisory applies to all Cisco products that run Cisco
IOS Software configured for Network Address Translation (NAT) and
that support the NAT SCCP Fragmentation Support feature. This feature
was first introduced in Cisco IOS Software Release 12.4(6)T.

To verify if NAT is enabled on a Cisco IOS device, log into the
device and issue the command "show ip nat statistics". The following
example shows a device configured with NAT:

    Router# show ip nat statistics
    Total translations: 2 (0 static, 2 dynamic; 0 extended)
    Outside interfaces: Serial0
    Inside interfaces: Ethernet1
    Hits: 135  Misses: 5
    Expired translations: 2
    Dynamic mappings:
    -- Inside Source
    access-list 1 pool mypool refcount 2
     pool mypool: netmask 255.255.255.0
            start 192.168.10.1 end 192.168.10.254
            type generic, total addresses 14, allocated 2 (14%), misses 0

You can also use the "show running-config | include ip nat" command to
verify if NAT has been enabled on the device.

In NAT traditional configurations, the term "inside" refers to those
networks that will be translated. Inside this domain, hosts will have
addresses in one address space, while on the "outside", they will
appear to have addresses in another address space when NAT is
configured. The first address space is referred to as the local
address space and the second is referred to as the global address
space. The "ip nat inside" and "ip nat outside" interface commands must
be present on the corresponding router interfaces in order for NAT to
be enabled.

The NAT Virtual Interface (NVI) feature removes the requirement to
configure an interface as either NAT inside or NAT outside. If the
device is configured for NVI, you can use the show ip nat nvi
statistics command in user EXEC or privileged EXEC mode, as shown in
the following example.

    Router# show ip nat nvi statistics

    Total active translations: 0 (0 static, 0 dynamic; 0 extended) NAT Enabled interfaces:
    Hits: 0  Misses: 0
    CEF Translated packets: 0, CEF Punted packets: 0 Expired translations: 0 Dynamic mappings:
    -- Inside Source
    [Id: 1] access-list 1 pool pool1 refcount 1213 pool pool1: netmask 255.255.255.0
             start 192.168.1.10 end 192.168.1.253
             start 192.168.2.10 end 192.168.2.253
             start 192.168.3.10 end 192.168.3.253
             start 192.168.4.10 end 192.168.4.253
             type generic, total addresses 976, allocated 222 (22%), misses 0  

    !---output truncated

In order to determine the software that is running on a Cisco IOS
product, log in to the device and issue the "show version" command to
display the system banner. Cisco IOS software identifies itself as
"Internetwork Operating System Software" or simply "IOS." On the next
line of output, the image name displays between parentheses, followed
by "Version" and the Cisco IOS release name. Other Cisco devices do
not have the show version command or give different output.

    router>show version
    Cisco IOS Software, 7200 Software (C7200-ADVSECURITYK9-M), Version 12.4(6)T2, RELEASE SOFTWARE (fc1)
    Technical Support: http://www.cisco.com/techsupport
    Copyright (c) 1986-2006 by Cisco Systems, Inc.
    Compiled Tue 16-May-06 16:09 by kellythw

    !---output truncated

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

Cisco IOS XR Software and IOS XE Software are not affected by this
vulnerability.

Cisco IOS devices not explicitly configured for NAT are not
vulnerable.

No other Cisco products are currently known to be affected by this
vulnerability.

Details
=======

The Skinny Client Control Protocol (SCCP) enables voice communication
between an SCCP client and a Call Manager (CM). Typically, the CM
provides service to the SCCP clients on TCP Port 2000 by default.
Initially, an SCCP client connects to the CM by establishing a TCP
connection; the client will also establish a TCP connection with a
secondary CM, if available.

The NAT SCCP Fragmentation Support feature enables the Skinny
Application Layer Gateway (ALG) to reassemble skinny control
messages. Since this feature was introduced in Cisco IOS version 12.4
(6)T, SCCP payloads requiring reassembly and NAT are no longer
dropped.

A series of crafted SCCP packets may cause a Cisco IOS router that is
running the NAT SCCP Fragmentation Support feature to reload.

This vulnerability is documented in Cisco Bug ID CSCsy09250 and has
been assigned the CVE ID CVE-2010-0584.

Vulnerability Scoring Details
=============================

Cisco has provided scores for the vulnerability in this advisory
based on the Common Vulnerability Scoring System (CVSS). The CVSS
scoring in this Security Advisory is done in accordance with CVSS
version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability
severity and helps determine urgency and priority of response.

Cisco has provided a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of
the vulnerability in individual networks.

Cisco has provided an FAQ to answer additional questions regarding
CVSS at:

http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to help compute the
environmental impact for individual networks at:

http://intellishield.cisco.com/security/alertmanager/cvss

CSCsy09250 - Bus error and crash when crafted packet is sent to device

CVSS Base Score - 7.8

Access Vector           - Network
Access Complexity       - Low
Authentication          - None
Confidentiality Impact  - None
Integrity Impact        - None
Availability Impact     - Complete

CVSS Temporal Score - 6.4

Exploitability          - Functional
Remediation Level       - Official-Fix
Report Confidence       - Confirmed

Impact
======

Successful exploitation of this vulnerability may cause the affected
device to reload. Repeated exploitation will result in a denial of
service (DoS) condition.

Software Versions 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.

Each row of the Cisco IOS software table (below) names a Cisco IOS
release train. If a given release train is vulnerable, then the
earliest possible releases that contain the fix (along with the
anticipated date of availability for each, if applicable) are listed
in the "First Fixed Release" column of the table. The "Bundle First
Fixed Release" column indicates the earliest possible releases which
have fixes for all the published vulnerabilities in this Cisco IOS
Security Advisory bundled publication. Cisco recommends upgrading to
the latest available release where possible.

+--------------------------------------------------------------------+
|   Major    |           Availability of Repaired Releases           |
|  Release   |                                                       |
|------------+-------------------------------------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 12.0-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|--------------------------------------------------------------------|
| There are no affected 12.0 based releases                          |
|--------------------------------------------------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 12.1-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|--------------------------------------------------------------------|
| There are no affected 12.1 based releases                          |
|--------------------------------------------------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 12.2-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|--------------------------------------------------------------------|
| There are no affected 12.2 based releases                          |
|--------------------------------------------------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 12.3-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|--------------------------------------------------------------------|
| There are no affected 12.3 based releases                          |
|--------------------------------------------------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 12.4-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|------------+---------------------------+---------------------------|
|            |                           | 12.4(25c)                 |
| 12.4       | Not Vulnerable            |                           |
|            |                           | 15.0(1)M1                 |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4GC     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            |                           | support organization per  |
| 12.4JA     | Not Vulnerable            | the instructions in       |
|            |                           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            |                           | support organization per  |
| 12.4JDA    | Not Vulnerable            | the instructions in       |
|            |                           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            |                           | support organization per  |
| 12.4JDC    | Not Vulnerable            | the instructions in       |
|            |                           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
| 12.4JDD    | Not Vulnerable            | 12.4(10b)JDD1             |
|------------+---------------------------+---------------------------|
| 12.4JHA    | Not Vulnerable            | Not Vulnerable            |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            |                           | support organization per  |
| 12.4JK     | Not Vulnerable            | the instructions in       |
|            |                           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            |                           | support organization per  |
| 12.4JL     | Not Vulnerable            | the instructions in       |
|            |                           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
|            |                           | Releases prior to 12.4    |
| 12.4JMA    | Not Vulnerable            | (3g)JMA2 are vulnerable,  |
|            |                           | release 12.4(3g)JMA2 and  |
|            |                           | later are not vulnerable  |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            |                           | support organization per  |
| 12.4JMB    | Not Vulnerable            | the instructions in       |
|            |                           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
| 12.4JX     | Not Vulnerable            | Vulnerable; first fixed   |
|            |                           | in 12.4JA                 |
|------------+---------------------------+---------------------------|
| 12.4MD     | 12.4(11)MD10              | 12.4(24)MD                |
|------------+---------------------------+---------------------------|
| 12.4MDA    | 12.4(22)MDA2              | 12.4(22)MDA2              |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; Contact your  |
|            | Releases up to and        | support organization per  |
| 12.4MR     | including 12.4(4)MR1 are  | the instructions in       |
|            | not vulnerable.           | Obtaining Fixed Software  |
|            |                           | section of this advisory  |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4SW     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | 12.4(20)T4                | 12.4(15)T12               |
|            |                           |                           |
|            | 12.4(22)T3                | 12.4(20)T5                |
| 12.4T      |                           |                           |
|            | 12.4(15)T10               | 12.4(24)T3; Available on  |
|            |                           | 26-MAR-10                 |
|            | 12.4(24)T2                |                           |
|            |                           | 12.4(22)T4                |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; migrate to    |
| 12.4XA     | Not Vulnerable            | any release in 15.0M or a |
|            |                           | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; migrate to    |
| 12.4XB     | Not Vulnerable            | any release in 15.0M or a |
|            |                           | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XC     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            |                           | Vulnerable; migrate to    |
| 12.4XD     | Not Vulnerable            | any release in 15.0M or a |
|            |                           | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XE     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XF     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XG     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XJ     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XK     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4XL     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XM     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4XN     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4XP     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XQ     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
| 12.4XR     | 12.4(22)XR3               | 12.4(22)XR3               |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XT     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4XV     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XW     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XY     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4XZ     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; migrate to    | Vulnerable; migrate to    |
| 12.4YA     | any release in 15.0M or a | any release in 15.0M or a |
|            | fixed 12.4T release.      | fixed 12.4 release.       |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4YB     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4YD     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|            |                           | 12.4(22)YE2               |
| 12.4YE     | 12.4(22)YE2               |                           |
|            |                           | 12.4(24)YE                |
|------------+---------------------------+---------------------------|
|            | Vulnerable; Contact your  | Vulnerable; Contact your  |
|            | support organization per  | support organization per  |
| 12.4YG     | the instructions in       | the instructions in       |
|            | Obtaining Fixed Software  | Obtaining Fixed Software  |
|            | section of this advisory  | section of this advisory  |
|------------+---------------------------+---------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 15.0-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|--------------------------------------------------------------------|
| There are no affected 15.0 based releases                          |
|--------------------------------------------------------------------|
|  Affected  |                           |  First Fixed Release for  |
| 15.1-Based |  First Fixed Release for  |   all Advisories in 24    |
|  Releases  |       this Advisory       |     March 2010 Bundle     |
|            |                           |        Publication        |
|--------------------------------------------------------------------|
| There are no affected 15.1 based releases                          |
+--------------------------------------------------------------------+

Cisco IOS-XE Software
+--------------------

+-------------------------------------------------------------------+
|       IOS-XE Release       |         First Fixed Release          |
|----------------------------+--------------------------------------|
| 2.1.x                      | Not Vulnerable                       |
|----------------------------+--------------------------------------|
| 2.2.x                      | Not Vulnerable                       |
|----------------------------+--------------------------------------|
| 2.3.x                      | Not Vulnerable                       |
|----------------------------+--------------------------------------|
| 2.4.x                      | Not Vulnerable                       |
|----------------------------+--------------------------------------|
| 2.5.x                      | Not Vulnerable                       |
|----------------------------+--------------------------------------|
| 2.6.x                      | Not Vulnerable                       |
+-------------------------------------------------------------------+

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

As workaround, an administrator can disable SCCP NAT support using
the "no ip nat service skinny tcp port 2000" command, as shown in the
following example:

    Router(config)# no ip nat service skinny tcp port 2000

Note: If your Cisco CallManager is using a TCP port for skinny
signaling different from the default port (2000), you need to adjust
this command accordingly.

Caution: This workaround is only feasible on networks where
SCCP traffic does not need to be processed by NAT. Please confirm
before implementing this workaround.

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

Cisco has released free software updates that address this
vulnerability. 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/en/US/docs/general/warranty/English/EU1KEN_.html

or as otherwise set forth at Cisco.com Downloads at:

http://www.cisco.com/public/sw-center/sw-usingswc.shtml

Do not contact psirt@cisco.com or security-alert@cisco.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 agreements 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 do not hold a Cisco
service contract, and customers who purchase through third-party
vendors but are unsuccessful in obtaining fixed software through
their point of sale should acquire 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@cisco.com

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

Refer to:

http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html

for additional TAC contact information, including 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. This
vulnerability was found during the resolution of customer service
requests.

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-20100324-sccp.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@cisco.com
  * first-bulletins@lists.first.org
  * bugtraq@securityfocus.com
  * vulnwatch@vulnwatch.org
  * cisco@spot.colorado.edu
  * cisco-nsp@puck.nether.net
  * full-disclosure@lists.grok.org.uk
  * comp.dcom.sys.cisco@newsgate.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 1.0    | 2010-March-24    | Initial public 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.h...

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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Cisco Security Advisory: Cisco IOS Software NAT Skinny Call Control Protocol Vulnerability

Cisco Systems Product Security Incident Response Team