===================================================================== CERT-Renater Note d'Information No. 2005/VULN229 _____________________________________________________________________ DATE : 31/03/2005 HARDWARE PLATFORM(S) : Cisco. OPERATING SYSTEM(S) : Cisco IOS. ====================================================================== Cisco Security Advisory: Cisco IPSec Malformed IKE Packet Vulnerability Revision 2.0 Last Updated 2005 March 30 at 1600 UTC (GMT) For Public Release 2004 April 8 at 1600 UTC (GMT) - ----------------------------------------------------------------------- Contents ======== Summary Affected Products Details Impact Software Versions and Fixes Obtaining Fixed Software Workarounds Exploitation and Public Announcements Status of This Notice: FINAL Distribution Revision History Cisco Security Procedures - ----------------------------------------------------------------------- Summary ======= A malformed Internet Key Exchange (IKE) packet may cause the Cisco Catalyst 6500 Series Switch or the Cisco 7600 Series Internet Router to reload. Only devices running Cisco IOS software with Crypto support are affected. This vulnerability is documented as Cisco bug ID CSCed30113. There are workarounds available to mitigate the effects of this vulnerability. Cisco has made free software available to address this vulnerability for all affected customers. The title of this advisory has been updated from "Cisco IPSec VPN Services Module Malformed IKE Packet Vulnerability" to the current title due to a change in the products affected no longer being limited to those devices with a VPN Services Module installed. This advisory will be posted at http://www.cisco.com/warp/public/707/cisco-sa-20040408-vpnsm.shtml Affected Products ================= Vulnerable Products +------------------ The vulnerability is only present if a Crypto feature set is being used. Customers can verify if they are running a Crypto feature set via the show version command: Router#show version Cisco Internetwork Operating System Software IOS (tm) c6sup2_rp Software (c6sup2_rp-PK9S-M), Version 12.2(18)SXD3, RELEASE SOFTWARE (fc1) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2004 by cisco Systems, Inc. Compiled Thu 09-Dec-04 19:35 by pwade Image text-base: 0x4002100C, data-base: 0x422E8000 Software that contains the 'K9' designation, as in the following line, includes the Crypto feature set: IOS (tm) c6sup2_rp Software (c6sup2_rp-PK9S-M), Version 12.2(18)SXD3, RELEASE SOFTWARE (fc1) All Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series Internet Router hardware running the following Cisco IOS releases are affected by this vulnerability. +----------------------------------------+ | Release | Affected Releases | | Train | | |------------+---------------------------| | 12.2SXA | earlier than 12.2(17b)SXA | |------------+---------------------------| | 12.2SXB | earlier than 12.2(17d)SXB | |------------+---------------------------| | 12.2SX | 12.2(17a)SX through 12.2 | | | (17a)SX4 | |------------+---------------------------| | 12.2SY | earlier than 12.2(14)SY3 | +----------------------------------------+ Products Confirmed Not Vulnerable ================================= Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Internet Routers running Cisco IOS release train 12.1E are not affected by this vulnerability. To determine your software revision, type show version at the command line prompt. No other Cisco products are currently known to be affected by this vulnerability. Details ======= A malformed IKE packet may cause an affected device to reload. This vulnerability could be used to conduct a Denial of Service (DoS) attack against a vulnerable device. This vulnerability is known to only exist in the modified IKE code which was incorporated in the 12.2SXA, 12.2SXB, 12.2SX and 12.2SY Cisco IOS software release trains. Cisco IOS devices with Crypto support will process IKE messages by default. More information can be found here: http://cco.cisco.com//en/US/products/sw/iosswrel/ps5187/products_command_reference_chapter09186a008017cf18.html#wp1071565 The Internetworking Terms and Cisco Systems Acronyms online guides can be found at http://www.cisco.com/univercd/cc/td/doc/cisintwk/. This vulnerability is documented in the Cisco Bug Toolkit as Bug ID CSCed30113 Impact ====== Successful exploitation of this vulnerability could result in a reload of the device. Repeated exploitation could result in a sustained DoS attack. Software Versions and Fixes =========================== This vulnerability has been fixed in the following Cisco IOS releases for the Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series Internet Router hardware: +----------------------------------------+ | Release | Fixed Releases | | Train | | |------------+---------------------------| | 12.2SXA | 12.2(17b)SXA and later | |------------+---------------------------| | 12.2SXB | 12.2(17d)SXB and later | |------------+---------------------------| | 12.2SX | Migrate to 12.2(17d)SXB | | | or later | |------------+---------------------------| | 12.2SY | 12.2(14)SY3 and later | +----------------------------------------+ Please refer to these documents for more information: * 12.2(17b)SXA Release Notes: http://www.cisco.com/en/US/products/sw/iosswrel/ps5014/prod_bulletin09186a00801df1dd.html * 12.2(17d)SXB Release Notes: http://www.cisco.com/en/US/products/sw/iosswrel/ps5012/prod_bulletin09186a00802078b5.html * 12.2(14)SY3 Release Notes: http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/relnotes/ol_3975.htm When considering software upgrades, please also consult http://www.cisco.com/warp/public/707/advisory.html 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") for assistance. Obtaining Fixed Software ======================== Cisco is offering free software upgrades to address this vulnerability for all affected customers. 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/tacpage/library/12.2/index.shtml. 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 assistance with the upgrade, which should be free of charge. Customers without Service Contracts +---------------------------------- Customers who purchase direct from Cisco but who do not hold a Cisco service contract and customers who purchase through third-party vendors but are unsuccessful at obtaining fixed software through their point of sale should get their upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows. * +1 800 553 2447 (toll free from within North America) * +1 408 526 7209 (toll call from anywhere in the world) * e-mail: tac@cisco.com Please 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. Please do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades. See 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. Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at http://www.cisco.com/public/sw-license-agreement.html, or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml. Workarounds =========== The effectiveness of any workaround 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 is the most appropriate for use in the intended network before it is deployed. Customers that do not require IPSec functionality on their devices can use the command 'no crypto isakmp enable' in configuration mode to disable processing of IPSec and eliminate their exposure. As a possible mitigation, access-lists could be applied on the affected IOS platforms to limit the source IP addresses permitted to establish IPSec sessions to the device. 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 reported to Cisco PSIRT by a customer. Status of This Notice: FINAL ============================ This is a final advisory. Although Cisco cannot guarantee the accuracy of all statements in this advisory, all of the facts have been checked to the best of our ability. Cisco does not anticipate issuing updated versions of this advisory unless there is some material change in the facts. Should there be a significant change in the facts, Cisco may update this advisory. Note: A stand-alone copy or paraphrase of the text of this security advisory 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 will be posted on Cisco's worldwide website at http://www.cisco.com/warp/public/707/cisco-sa-20040408-vpnsm.shtml In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key having the fingerprint 8C82 5207 0CA9 ED40 1DD2 EE2A 7B31 A8CF 32B6 B590 and is posted to the following e-mail and Usenet news recipients. * cust-security-announce@cisco.com * first-teams@first.org (includes CERT/CC) * bugtraq@securityfocus.com * vulnwatch@vulnwatch.org * cisco@spot.colorado.edu * cisco-nsp@puck.nether.net * full-disclosure@lists.netsys.com * comp.dcom.sys.cisco@newsgate.cisco.com * Various internal Cisco mailing lists 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 the | | | | advisory to | | | | reflect | | | | devices | | | | without the | | | | VPNSM may | | | | be | | | | affected. | | | | Added 12.2 | | | | (17d)SX as | | Revision | 2005-March-30 | an affected | | 2.0 | | release | | | | train. | | | | Added | | | | information | | | | for | | | | determining | | | | the | | | | presence of | | | | the crypto | | | | feature | | | | set. | |----------+----------------+-------------| | | | Updated the | | | | 12.2(14) | | | | SY03 | | | | Release | | Revision | 2005-January-4 | Notes URL | | 1.2 | | in the | | | | Software | | | | Fixes and | | | | Versions | | | | section. | |----------+----------------+-------------| | | | Removed | | | | 12.2ZA as a | | Revision | | vulnerable | | 1.1 | 2004-April-8 | Cisco IOS | | | | software | | | | release | | | | train. | |----------+----------------+-------------| | Revision | | Initial | | 1.0 | 2004-April-8 | 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. ====================================================================== ========================================================= Les serveurs de référence du CERT-Renater http://www.urec.fr/securite http://www.cru.fr/securite http://www.renater.fr ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 151 bd de l'Hopital | fax : 01-53-94-20-41 + + 75013 Paris | email: certsvp@renater.fr + =========================================================