-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Cisco IOS Software NAT Skinny Call Control Protocol Vulnerability
Advisory ID: cisco-sa-20100324-sccp Revision 1.0 For Public Release 2010 March 24 1600 UTC (GMT) +--------------------------------------------------------------------- Summary ======= 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 ps...@cisco.com or security-al...@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: t...@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-annou...@cisco.com * first-bullet...@lists.first.org * bugt...@securityfocus.com * vulnwa...@vulnwatch.org * ci...@spot.colorado.edu * cisco-...@puck.nether.net * full-disclosure@lists.grok.org.uk * comp.dcom.sys.ci...@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.html 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----- iD8DBQFLqO4X86n/Gc8U/uARArHuAKCNnTQkJtzQiDJ1RY0ERYFGDffpcwCdHruh U/8efv1qDpFghQLXNjqnSIg= =NuJi -----END PGP SIGNATURE----- _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
