-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Cisco IOS NAT Skinny Call Control Protocol Vulnerability Advisory ID: cisco-sa-20080924-sccp http://www.cisco.com/warp/public/707/cisco-sa-20080924-sccp.shtml Revision 1.0 For Public Release 2008 September 24 1600 UTC (GMT) - --------------------------------------------------------------------- Summary ======= A series of segmented Skinny Call Control Protocol (SCCP) 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-20080924-sccp.shtml Note: The September 24, 2008 IOS Advisory bundled publication includes twelve Security Advisories. Eleven of the advisories address vulnerabilities in Cisco's IOS software, and one advisory addresses vulnerabilities in Cisco Unified Communications Manager. Each Advisory lists the releases that correct the vulnerability described in the Advisory. Please reference the following software table to find a release that fixes all published IOS software Advisories as of September 24th, 2008: http://www.cisco.com/warp/public/707/cisco-sa-20080924-bundle.shtml Individual publication links are listed below: * http://www.cisco.com/warp/public/707/cisco-sa-20080924-cucm.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-iosfw.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-iosips.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-ipc.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-l2tp.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-mfi.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-multicast.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-sccp.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-sip.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-ssl.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-ubr.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20080924-vpn.shtml Affected Products ================= Vulnerable Products +------------------ This security advisory applies to all Cisco products that run Cisco IOS Software configured for NAT and that support the NAT SCCP Fragmentation Support feature. This feature was first introduced in Cisco IOS version 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 Alternatively, you can use the show running-config | include ip nat command to verify if NAT has been enabled on the router interfaces. Note: With reference to NAT, 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. In order to determine the software that runs 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. The following example shows output from a device that runs an IOS image: 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 <more output removed for brevity> Products Confirmed Not Vulnerable +-------------------------------- Cisco IOS XR and IOS XE 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 these vulnerabilities. Details ======= The Skinny Call 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 prevents skinny control message exchanges from failing in a TCP segmentation scenario because the NAT Skinny Application Layer Gateway (ALG) is able to reassemble the skinny control messages. A segmented payload that requires an IP or port translation will no longer be dropped. The NAT SCCP Fragmentation Support feature was introduced in Cisco IOS version 12.4(6)T. A series of fragmented SCCP messages 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 CSCsg22426 and CSCsi17020, and has been assigned CVE identifiers CVE-2008-3810 and CVE-2008-3811. Vulnerability Scoring Details ============================= Cisco has provided scores for the vulnerabilities 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 CSCsg22426 - Cisco IOS Skinny Call Control Protocol (SCCP) Vulnerability 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 CSCsi17020 - Router may reload after NAT with certain skinny packets 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 "Recommended Release" column indicates the releases which have fixes for all the published vulnerabilities at the time of this Advisory. 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. Cisco recommends upgrading to a release equal to or later than the release in the "Recommended Releases" column of the table. +-------------------------------------------------------------------+ | Major Release | Availability of Repaired Releases | |-------------------+-----------------------------------------------| | Affected | | | | 12.0-Based | First Fixed Release | Recommended Release | | Releases | | | |-------------------------------------------------------------------| | There are no affected 12.0 based releases | |-------------------------------------------------------------------| | Affected | | | | 12.1-Based | First Fixed Release | Recommended Release | | Releases | | | |-------------------------------------------------------------------| | There are no affected 12.1 based releases | |-------------------------------------------------------------------| | Affected | | | | 12.2-Based | First Fixed Release | Recommended Release | | Releases | | | |-------------------+-----------------------+-----------------------| | 12.2 | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2B | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2BC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2BW | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2BX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2BY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2BZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2CX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2CY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2CZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2DA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2DD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2DX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2EW | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2EWA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2EX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2EY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2EZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2FX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2FY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2FZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IRB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXF | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2IXG | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2JA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2JK | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2MB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2MC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2S | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SBC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SCA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SEA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SEB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SEC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SED | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SEE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SEF | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SEG | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SG | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SGA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SL | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SM | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SO | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SRA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SRB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SRC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SU | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SV | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SVA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SVC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SVD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SW | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SXA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SXB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SXD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SXE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SXF | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | | Not Vulnerable | | | 12.2SXH | | | | | http://www.cisco.com/ | | | | go/pn | | |-------------------+-----------------------+-----------------------| | 12.2SY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2SZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2T | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2TPC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XF | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XG | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XH | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XI | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XJ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XK | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XL | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XM | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XN | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XNA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XNB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XO | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XQ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XR | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XS | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XT | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XU | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XV | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2XW | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YF | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YG | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YH | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YJ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YK | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YL | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YM | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YN | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YO | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YP | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YQ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YR | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YS | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YT | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YU | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YV | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YW | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2YZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZE | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZF | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZG | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZH | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZJ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZL | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZP | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZU | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.2ZYA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | Affected | | | | 12.3-Based | First Fixed Release | Recommended Release | | Releases | | | |-------------------------------------------------------------------| | There are no affected 12.3 based releases | |-------------------------------------------------------------------| | Affected | | | | 12.4-Based | First Fixed Release | Recommended Release | | Releases | | | |-------------------+-----------------------+-----------------------| | 12.4 | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JK | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JL | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JMA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JMB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JMC | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4JX | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4MD | 12.4(11)MD4 | 12.4(15)MD1 | |-------------------+-----------------------+-----------------------| | 12.4MR | 12.4(16)MR | 12.4(19)MR | |-------------------+-----------------------+-----------------------| | | 12.4(15)SW2; | 12.4(15)SW2; | | 12.4SW | Available on | Available on | | | 28-SEP-08 | 28-SEP-08 | |-------------------+-----------------------+-----------------------| | | 12.4(11)T4 | | | | | | | | 12.4(15)T2 | | | | | | | 12.4T | 12.4(20)T | 12.4(15)T7 | | | | | | | 12.4(6)T11 | | | | | | | | 12.4(9)T5 | | |-------------------+-----------------------+-----------------------| | 12.4XA | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4XB | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4XC | Vulnerable; first | 12.4(15)T7 | | | fixed in 12.4T | | |-------------------+-----------------------+-----------------------| | 12.4XD | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4XE | Vulnerable; first | 12.4(15)T7 | | | fixed in 12.4T | | |-------------------+-----------------------+-----------------------| | 12.4XF | Vulnerable; first | 12.4(15)T7 | | | fixed in 12.4T | | |-------------------+-----------------------+-----------------------| | 12.4XG | 12.4(9)XG3 | 12.4(9)XG3 | |-------------------+-----------------------+-----------------------| | 12.4XJ | Vulnerable; first | 12.4(15)T7 | | | fixed in 12.4T | | |-------------------+-----------------------+-----------------------| | 12.4XK | Vulnerable; first | 12.4(15)T7 | | | fixed in 12.4T | | |-------------------+-----------------------+-----------------------| | 12.4XL | 12.4(15)XL2 | 12.4(15)XL2 | |-------------------+-----------------------+-----------------------| | 12.4XM | 12.4(15)XM1 | 12.4(15)XM1 | |-------------------+-----------------------+-----------------------| | 12.4XN | Vulnerable; contact | | | | TAC | | |-------------------+-----------------------+-----------------------| | 12.4XP | Vulnerable; contact | | | | TAC | | |-------------------+-----------------------+-----------------------| | 12.4XQ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4XR | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4XT | Vulnerable; first | 12.4(15)T7 | | | fixed in 12.4T | | |-------------------+-----------------------+-----------------------| | 12.4XV | Vulnerable; contact | | | | TAC | | |-------------------+-----------------------+-----------------------| | 12.4XW | 12.4(11)XW7 | 12.4(11)XW9 | |-------------------+-----------------------+-----------------------| | 12.4XY | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4XZ | Not Vulnerable | | |-------------------+-----------------------+-----------------------| | 12.4YA | 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. Obtaining Fixed Software ======================== Cisco has released free software updates that address these vulnerabilities. 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/products/prod_warranties_item09186a008088e31f.htm... 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/warp/public/687/Directory/DirTAC.shtml 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. 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-20080924-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-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 ================ +----------------------------------------+ | Revision | | Initial | | 1.0 | 2008-September-24 | 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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (Darwin) iEYEARECAAYFAkjaLdUACgkQ86n/Gc8U/uBM1ACeMzZ03zyWQhMRkiHOGUi20KeT NAoAnR9OVAOw7st0mwFWyEmatcQIxy2v =CqpX -----END PGP SIGNATURE-----