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AU-2007.0004 -- AusCERT Update - [Cisco] - SIP DoS vulnerability also affects IOS devices fully configured for SIP

Date: 11 February 2007
References: ESB-2007.0070  

Click here for printable version
Click here for PGP verifiable version
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

AusCERT Update AU-2007.0004 - [Cisco]
SIP DoS vulnerability also affects IOS devices fully configured for SIP
12 February 2007

        AusCERT Update Summary
        ----------------------

Product:              IOS 12.3 and 12.4
Publisher:            Cisco Systems
Impact:               Denial of Service
Access:               Remote/Unauthenticated
CVE Names:            CVE-2007-0648

Ref:                  ESB-2007.0070

Original Bulletin:    
  http://www.cisco.com/warp/public/707/cisco-sa-20070131-sip.shtml

- --------------------------BEGIN INCLUDED TEXT--------------------

Cisco PSIRT has updated the Security Advisory previously named "Cisco
Security Advisory: SIP Packet Reloads IOS Devices Not Configured for
SIP" to revision 2.0, which contains new information regarding
afffected products and software versions.

Please note, new information has become available, and devices which
are properly configured for SIP processing are also vulnerable to this
issue.

- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Cisco Security Advisory: SIP Packets Reload IOS Devices with support
for SIP

Advisory ID: cisco-sa-20070131-sip

http://www.cisco.com/warp/public/707/cisco-sa-20070131-sip.shtml

Revision 2.0

Last Updated 2007 February 9 2100 UTC (GMT)

For Public Release 2007 January 31 0900 UTC (GMT)

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

Summary
=======

Cisco devices running an affected version of Internetwork Operating
System (IOS) which supports Session Initiation Protocol (SIP) are
affected by a vulnerability that may lead to a reload of the device
when receiving a specific series of packets destined to port 5060.
This issue is compounded by a related bug which allows traffic to TCP
5060 and UDP port 5060 on devices not configured for SIP.

There are no known instances of intentional exploitation of this
issue. However, Cisco has observed data streams that appear to be
unintentionally triggering the vulnerability.

Workarounds exist to mitigate the effects of this problem on devices
which do not require SIP.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20070131-sip.shtml.

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

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

Any Cisco device which runs a vulnerable version of IOS and supports
SIP processing could be vulnerable. This includes IOS versions
12.3(4)XH, 12.3(4)XQ, 12.3(7)XR, 12.3(7)XS, 12.3(8)JA, 12.3(8)T,
12.3(8) XU, 12.3(8)XW, 12.3(8)XX, 12.3(8)XY, 12.3(8)YA, 12.3(8)YG,
12.3(8)YH, 12.3(8)YI, 12.3(8)ZA, 12.4 Mainline and 12.4T
onward. Routers configured as SIP Public Switched Telephone Network
(PSTN) Gateways are vulnerable, as are routers configured as SIP
Session Border Controllers (SBCs) and the CAT6000-CMM card.

To determine if your device has SIP enabled, enter the commands show
ip sockets and show tcp brief all. Below is an example of a router
running code without the fix, and without the workaround enabled. The
router in this example is running the vulnerable image
c7200-p-mz.124-3.bin:

    Router#show ip sockets
    Proto    Remote      Port      Local       Port  In Out Stat TTY OutputIF
    17 0.0.0.0             0  --any--          5060   0   0  211   0
    17 0.0.0.0             0 192.168.100.2       67   0   0 2211   0
    17 0.0.0.0             0 192.168.100.2     2517   0   0   11   0
    

The first line with UDP Port 5060 shows that UDP SIP is enabled.

    Router#show tcp brief all
    TCB       Local Address           Foreign Address        (state)
    2051E680  *.5060                  *.*                    LISTEN
    

The above lines with *.5060 show that TCP SIP is enabled.

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

Devices that do not support SIP processing are not affected by this
issue. This includes but is not limited to the 6500, 7600, 10000
series and 12000 series. To confirm that a device is not vulnerable
to this issue, ensure that ports TCP 5060 and UDP 5060 are not open
on the device with the commands show tcp brief all and show ip
sockets. Below is an example of a router running the fixed image
c7200-js-mz.124-5b.bin which is not vulnerable to this issue.

    Router#show tcp brief all
    
    Router#show ip sockets
    Proto    Remote      Port      Local       Port  In Out Stat TTY OutputIF
    17 0.0.0.0             0 192.168.100.2      67   0   0 2211   0
    

No lines with UDP Port 5060 are shown and UDP SIP is not enabled. In
this example, UDP port 67 is used by DHCP which is not related to
this vulnerability.

Details
=======

SIP is a protocol designed for use in IP voice networks and is widely
used for Voice over Internet Protocol (VoIP) communications
worldwide.

Cisco devices running certain versions of IOS with support for SIP
services may be affected by a vulnerability that leads to a reload of
the device with a crafted series of SIP packets to either TCP port
5060 or UDP port 5060. This vulnerability affects routers that contain
any SIP configuration, including SIP gateways. This issue is being
tracked as Cisco Bug ID CSCsh58082.

In addition, certain versions of IOS with support for SIP services may
process SIP messages even if they are not configured for SIP
operation. To process SIP messages IOS will open UDP port 5060 and TCP
port 5060 for listening. The Cisco Bug ID that documents the issue of
IOS processing SIP messages without being configured for SIP operation
is CSCsb25337. The fix for this bug turns off the listening ports TCP
5060 and UDP 5060.

A device must have an open SIP port to be vulnerable to this issue.
Devices which do not listen on TCP 5060 or UDP 5060 are not
vulnerable. Because SIP utilizes UDP as a transport, it is possible
to spoof the sender's IP address, which may defeat ACLs that permit
communication to these ports from trusted IP addresses.

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

Cisco is providing scores for the vulnerabilities in this advisory
based on the Common Vulnerability Scoring System (CVSS).

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

Cisco PSIRT will set the bias in all cases to normal. Customers are
encouraged to apply the bias parameter when determining the
environmental impact of a particular vulnerability.

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

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

CSCsb25337 - unnecessary tcp ports opened in default router config

CVSS Base Score: 2.3       
- - - Access Vector: Remote          
- - - Access Complexity: Low         
- - - Authentication: Not Required   
- - - Confidentiality Impact: Partial
- - - Integrity Impact: None   
- - - Availability Impact: None
- - - Impact Bias: Normal   

CVSS Temporal Score: 1.9        
- - - Exploitability: Functional    
- - - Remediation Level: Official Fix
- - - Report Confidence: Confirmed

CSCsb25337 causes processing of SIP messages to occur even when an IOS
device is not configured for correct SIP operation. The scoring of
this bug has been done taking in consideration the potential for
reconnaissance since this bug, by itself, has no potential for
denial-of-service.

CSCsh58082 - SIP: A router may reload due to SIP traffic

CVSS Base Score: 2.3       
- - - Access Vector: Remote          
- - - Access Complexity: Low         
- - - Authentication: Not Required   
- - - Confidentiality Impact: None
- - - Integrity Impact: None   
- - - Availability Impact: Complete
- - - Impact Bias: Normal   

CVSS Temporal Score: 1.9        
- - - Exploitability: High 
- - - Remediation Level: Workaround
- - - Report Confidence: Confirmed

Impact
======

Successful exploitation of the vulnerability may result in a reload
of the device. The issue may be repeatedly exploited, leading to an
extended Denial Of Service (DoS) condition.

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.

Each row of the Cisco IOS software table (below) describes a release
train and the platforms or products for which it is intended. If a
given release train is vulnerable, then the earliest possible
releases that contain the fix (the "First Fixed Release") and the
anticipated date of availability for each are listed in the "Rebuild"
and "Maintenance" columns. A device running a release in the given
train that is earlier than the release in a specific column (less
than the First Fixed Release) is known to be vulnerable. The release
should be upgraded at least to the indicated release or a later
version (greater than or equal to the First Fixed Release label).

For more information on the terms "Rebuild" and "Maintenance," consult
the following URL: http://www.cisco.com/warp/public/620/1.html.

The following table is written to indicate the vulnerable and fixed
status of CSCsh58082, which is the bug responsible for the device
reload. This table also contains information about IOS releases that
are fixed for CSCsb25337, which turns off processing of SIP messages
when the device is not fully configured for SIP operation.  At the
time of the 2.0 publishing, there are no fixes for CSCsh58082.

+---------------------------------------+
| Major Release |    Availability of    |
|               |   Repaired Releases   |
|---------------+-----------------------|
| Affected      |         |             |
| 12.0-Based    | Rebuild | Maintenance |
| Release       |         |             |
|---------------+-----------------------|
| 12.0          | All 12.0 releases are |
|               | not vulnerable        |
|---------------+-----------------------|
| Affected      |         |             |
| 12.1-Based    | Rebuild | Maintenance |
| Release       |         |             |
|---------------+-----------------------|
| 12.1          | All 12.1 releases are |
|               | not vulnerable        |
|---------------+-----------------------|
| Affected      |         |             |
| 12.2-Based    | Rebuild | Maintenance |
| Release       |         |             |
|---------------+-----------------------|
| 12.2          | All 12.2 releases are |
|               | not vulnerable        |
|---------------+-----------------------|
| Affected      |         |             |
| 12.3-Based    | Rebuild | Maintenance |
| Release       |         |             |
|---------------+-----------------------|
| 12.3          | Not vulnerable        |
|---------------+-----------------------|
| 12.3B         | Not vulnerable        |
|---------------+-----------------------|
| 12.3BC        | Not vulnerable        |
|---------------+-----------------------|
| 12.3BW        | Not vulnerable        |
|---------------+-----------------------|
| 12.3JA        | Vulnerable starting   |
|               | with 12.3(8)JA        |
|---------------+-----------------------|
| 12.3JEA       | Vulnerable starting   |
|               | with 12.3(8)JEA       |
|---------------+-----------------------|
| 12.3JEB       | Not vulnerable        |
|---------------+-----------------------|
| 12.3JK        | Not vulnerable        |
|---------------+-----------------------|
| 12.3JX        | Not vulnerable        |
|---------------+-----------------------|
| 12.3T         | Vulnerable starting   |
|               | with 12.3(8)T         |
|---------------+-----------------------|
| 12.3TPC       | Not vulnerable        |
|---------------+-----------------------|
| 12.3XA        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XB        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XC        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XD        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XE        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XF        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XG        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XH        | Vulnerable starting   |
|               | with 12.3(4)XH        |
|---------------+-----------------------|
| 12.3XI        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XJ        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XK        | Not vulnerable        |
|---------------+-----------------------|
| 12.3XQ        | Vulnerable starting   |
|               | with 12.3(4)XQ        |
|---------------+-----------------------|
| 12.3XR        | Vulnerable starting   |
|               | with 12.3(7)XR        |
|---------------+-----------------------|
| 12.3XS        | Vulnerable starting   |
|               | with 12.3(7)XS        |
|---------------+-----------------------|
| 12.3XU        | Vulnerable starting   |
|               | with 12.3(8)XU        |
|---------------+-----------------------|
| 12.3XW        | Vulnerable starting   |
|               | with 12.3(8)XW        |
|---------------+-----------------------|
| 12.3XX        | Vulnerable starting   |
|               | with 12.3(8)XX        |
|---------------+-----------------------|
| 12.3XY        | Vulnerable starting   |
|               | with 12.3(8)XY        |
|---------------+-----------------------|
| 12.3YA        | Vulnerable starting   |
|               | with 12.3(8)YA        |
|---------------+-----------------------|
| 12.3YD        | Not vulnerable        |
|---------------+-----------------------|
| 12.3YF        | Not vulnerable        |
|---------------+-----------------------|
| 12.3YG        |         |             |
|               |         |             |
| Vulnerable    |         |             |
| starting with |         |             |
| 12.3(8)YG.    |         |             |
| Releases      | 12.3(8) |             |
| shown         | YG5     |             |
| indicate      |         |             |
| where SIP     |         |             |
| ports are     |         |             |
| closed by     |         |             |
| default.      |         |             |
|---------------+-----------------------|
| 12.3YH        | Vulnerable starting   |
|               | with 12.3(8)YH        |
|---------------+-----------------------|
| 12.3YI        | Vulnerable starting   |
|               | with 12.3(8)YI        |
|---------------+-----------------------|
| 12.3YJ        | Not vulnerable        |
|---------------+-----------------------|
| 12.3YK        | Vulnerable.           |
|---------------+-----------------------|
| 12.3YM        |         |             |
|               |         |             |
| Vulnerable.   |         |             |
| Releases      |         |             |
| shown         | 12.3    |             |
| indicate      | (14)YM8 |             |
| where SIP     |         |             |
| ports are     |         |             |
| closed by     |         |             |
| default.      |         |             |
|---------------+-----------------------|
| 12.3YQ        | Vulnerable.           |
|---------------+-----------------------|
| 12.3YS        | Not vulnerable        |
|---------------+-----------------------|
| 12.3YT        | Vulnerable            |
|---------------+-----------------------|
| 12.3YU        | Vulnerable            |
|---------------+-----------------------|
| 12.3YX        |         |             |
|               |         |             |
| Vulnerable.   |         |             |
| Releases      |         |             |
| shown         | 12.3    |             |
| indicate      | (14)YX2 |             |
| where SIP     |         |             |
| ports are     |         |             |
| closed by     |         |             |
| default.      |         |             |
|---------------+-----------------------|
| 12.3YZ        | Not vulnerable        |
|---------------+-----------------------|
| Affected      |         |             |
| 12.4-Based    | Rebuild | Maintenance |
| Release       |         |             |
|---------------+---------+-------------|
| 12.4          | 12.4    |             |
|               | (3d)    |             |
| Vulnerable.   |         |             |
|Releases       |---------+-------------|
| shown         | 12.4    |             |
| indicate      | (5b)    |             |
| where SIP     |         |             |
|port is        |---------+-------------|
| closed by     | 12.4    |             |
| default.      | (7a)    | 12.4(8)     |
|               |         |             |
|---------------+---------+-------------|
| 12.4MR        |         |             |
|               |         |             |
| Vulnerable.   |         |             |
| Releases      |         |             |
| shown         |         | 12.4(6)MR   |
| indicate      |         |             |
| where SIP     |         |             |
| ports are     |         |             |
| closed by     |         |             |
| default.      |         |             |
|---------------+-----------------------|
| 12.4SW        |                       |
|               |                       |
| Vulnerable.   |                       |
| Releases      | All 12.4SW releases   |
| shown         | have the SIP ports    |
| indicate      | closed by default     |
| where SIP     |                       |
| ports are     |                       |
| closed by     |                       |
| default.      |                       |
|---------------+-----------------------|
| 12.4T         | 12.4(2) |             |
|               | T5      |             |
| Vulnerable.   |         |             |
|Releases       |---------+-------------|
| shown         | 12.4(4) |             |
| indicate      | T3      |             |
| where SIP     |         |             |
|ports are      |---------+-------------|
| closed by     | 12.4(6) |             |
| default.      | T1      | 12.4(9)T    |
|               |         |             |
|---------------+-----------------------|
| 12.4XA        | Vulnerable            |
|---------------+-----------------------|
| 12.4XB        |         |             |
|               |         |             |
| Vulnerable.   |         |             |
| Releases      |         |             |
| shown         | 12.4(4) |             |
| indicate      | XB2     |             |
| where SIP     |         |             |
| ports are     |         |             |
| closed by     |         |             |
| default.      |         |             |
|---------------+-----------------------|
| 12.4XC        | Vulnerable; contact   |
|               | TAC                   |
|---------------+-----------------------|
| 12.4XD        |         |             |
|               |         |             |
| Vulnerable.   |         |             |
| Releases      |         |             |
| shown         | 12.4(4) |             |
| indicate      | XD2     |             |
| where SIP     |         |             |
| ports are     |         |             |
| closed by     |         |             |
| default.      |         |             |
|---------------+-----------------------|
| 12.4XE        |                       |
|               |                       |
| Vulnerable.   |                       |
| Releases      | All 12.4XE have the   |
| shown         | SIP ports closed by   |
| indicate      | default               |
| where SIP     |                       |
| ports are     |                       |
| closed by     |                       |
| default.      |                       |
|---------------+-----------------------|
| 12.4XG        | Not Vulnerable        |
|---------------+-----------------------|
| 12.4XJ        |                       |
|               |                       |
| Vulnerable.   |                       |
| Releases      | All 12.4XJ have the   |
| shown         | SIP ports closed by   |
| indicate      | default               |
| where SIP     |                       |
| ports are     |                       |
| closed by     |                       |
| default.      |                       |
|---------------+-----------------------|
| 12.4XP        |                       |
|               |                       |
| Vulnerable.   |                       |
| Releases      | All 12.4XP have the   |
| shown         | SIP ports closed by   |
| indicate      | default               |
| where SIP     |                       |
| ports are     |                       |
| closed by     |                       |
| default.      |                       |
|---------------+-----------------------|
| 12.4XT        |                       |
|               |                       |
| Vulnerable.   |                       |
| Releases      | All 12.4XT have the   |
| shown         | SIP ports closed by   |
| indicate      | default               |
| where SIP     |                       |
| ports are     |                       |
| closed by     |                       |
| default.      |                       |
+---------------------------------------+

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

Additional mitigations that can be deployed on Cisco devices within
the network are available in the Cisco Applied Intelligence companion
document for this advisory:
http://www.cisco.com/warp/public/707/cisco-air-20070131-sip.shtml

Disable SIP listening ports
+--------------------------

For devices which do not require SIP to be enabled, the simplest and
most effective workaround is to disable SIP processing on the device
with the following commands.

Warning: When applying this workaround to devices which are
processing MGCP or H.323 calls, the device will not allow you to stop
SIP processing while active calls are being processed. Under these
circumstances, this workaround should be implemented during a
maintenance window when active calls can be briefly stopped.

    Enter configuration commands, one per line.  End with CNTL/Z.
    Router(config)#sip-ua
    Router(config-sip-ua)#no transport udp
    Router(config-sip-ua)#no transport tcp
    Router(config-sip-ua)#end
    

After applying this workaround the commands show ip sockets and show
tcp brief all will not show the device listening on UDP and TCP port
5060:

    Router#show ip sockets
    Proto    Remote      Port      Local       Port  In Out Stat TTY
     17   --listen--          9.13.32.18       2887   0   0   11   0
    
    Router#show tcp brief all
    TCB       Local Address           Foreign Address        (state)
    6649A5A4  *.1720                  *.*                    LISTEN
    66CDC764  *.1723                  *.*                    LISTEN
    

Control Plane Policing
+---------------------

For devices which do not need to run SIP, you can use Control Plane
Policing (CoPP) to block all SIP access to the device. Cisco IOS
software releases 12.0S, 12.2SX, 12.2S, 12.3T, 12.4, and 12.4T
support the CoPP feature. CoPP may be configured on a device to
protect the management and control planes to minimize the risk and
effectiveness of direct infrastructure attacks by explicitly
permitting only authorized traffic sent to infrastructure devices in
accordance with existing security policies and configurations. The
following example can be adapted to your network.

Warning: Because SIP utilizes UDP as a transport, it is possible to
spoof the sender's IP address, which may defeat ACLs that permit
communication to these ports from trusted IP addresses.

    !-- Permit all TCP and UDP SIP traffic sent to all IP addresses
    !-- configured on all interfaces of the affected device so that it
    !-- will be policed and dropped by the CoPP feature.
    
    
    access-list 100 permit tcp any any eq 5060
    access-list 100 permit udp any any eq 5060
    
    
    !-- Permit (Police or Drop)/Deny (Allow) all other Layer3 and Layer4
    !-- traffic in accordance with existing security policies and
    !-- configurations for traffic that is authorized to be sent
    !-- to infrastructure devices.
    
    
    
    !-- Create a Class-Map for traffic to be policed by
    !-- the CoPP feature.
    
    
    class-map match-all drop-sip-class
      match access-group 100
    
    
    !-- Create a Policy-Map that will be applied to the
    !-- Control-Plane of the device.
    
    
    policy-map drop-sip-traffic
      class drop-sip-class
        drop
    
    
    !-- Apply the Policy-Map to the Control-Plane of the
    !-- device.
    
    
    control-plane
      service-policy input drop-sip-traffic
    

In the above CoPP example, the access control list entries (ACEs)
which match the potential exploit packets with the "permit" action
result in these packets being discarded by the policy-map "drop"
function, while packets that match the "deny" action (not shown) are
not affected by the policy-map drop function. Additional information
on the configuration and use of the CoPP feature can be found at

http://www.cisco.com/en/US/products/ps6642/products_white_paper0900aecd804fa16a.shtml

and

http://www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_feature_guide09186a008052446b.html

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.htm, 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@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 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)
  * +1 408 526 7209 (toll call from anywhere in the world)
  * e-mail: tac@cisco.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
=====================================

This issue was first reported to Cisco by a customer. There are no
known instances of intentional exploitation of this issue. However,
Cisco has observed data streams that appear to be unintentionally
triggering the vulnerability.

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-20070131-sip.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-teams@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
================

+---------------------------------------------+
|          |                 | Updated        |
|          |                 | document to    |
|          |                 | reflect that   |
|          |                 | all products   |
|          |                 | with open      |
|          |                 | ports 5060 are |
|          |                 | vulnerable.    |
|          |                 |                |
|          |                 | Updated        |
|          |                 | Vulnerable     |
|          |                 | Products with  |
|          |                 | voice          |
|          |                 | gateways,      |
|          |                 | SBCs, and      |
|          |                 | CAT6000-CMM.   |
| Revision |                 |                |
| 2.0      | 2007-February-9 | Updated the    |
|          |                 | software table |
|          |                 | to reflect     |
|          |                 | vulnerability  |
|          |                 | of 12.3(4)XH,  |
|          |                 | 12.3(4)XQ,     |
|          |                 | 12.3(7)XR,     |
|          |                 | 12.3(7)XS,     |
|          |                 | 12.3(8)JA,     |
|          |                 | 12.3(8)XU,     |
|          |                 | 12.3(8)XW,     |
|          |                 | 12.3(8)XX,     |
|          |                 | 12.3(8)XY,     |
|          |                 | 12.3(8)YA,     |
|          |                 | 12.3(8)YH,     |
|          |                 | 12.3(8)YI and  |
|          |                 | 12.3(8)ZA.     |
|----------+-----------------+----------------|
|          |                 | Added Common   |
|          |                 | Vulnerability  |
|          |                 | Scoring System |
|          |                 | (CVSS) scoring |
|          |                 | for all bugs   |
|          |                 | mentioned in   |
|          |                 | the advisory.  |
|          |                 |                |
|          |                 | Added          |
| Revision |                 | CSCsh58082     |
| 1.1      | 2007-January-31 |                |
|          |                 |       as the   |
|          |                 | Csco Bug ID   |
|          |                 | that tracks    |
|          |                 | the root cause |
|          |                 | of the         |
|          |                 | vulnerability. |
|          |                 |                |
|          |                 | Minor wording  |
|          |                 | changes.       |
|----------+-----------------+----------------|
| Revision | 2007-January-31 | Initial public |
| 1.0      |                 | 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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- --------------------------END INCLUDED TEXT--------------------

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