__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN SIP Packet Reloads IOS Devices Not Configured for SIP [Cisco Security Advisory Document ID: 81825] January 31, 2007 18:00 GMT Number R-118 ______________________________________________________________________________ PROBLEM: Cisco devices running IOS which support voice and are not configured for Session Initiated Protocol (SIP) are vulnerable to a crash under yet to be determined conditions, but isolated to traffic destined to Port 5060. PLATFORM: IOS releases that include voice support after 12.3(14)T, 12.3(8)YC1, 12.3(8)YG and all of 12.4 are affected. Please see the fixed software table for a complete list of fixed and vulnerable trains. DAMAGE: Can crash a device running Cisco IOS software which supports voice but is not configured for SIP. SOLUTION: Upgrade to the appropriate version. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. Can crash a device running Cisco IOS ASSESSMENT: software which supports voice but is not configured for SIP. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/r-118.shtml ORIGINAL BULLETIN: http://www.cisco.com/en/US/products/products_security_ advisory09186a00807d3715.shtml ______________________________________________________________________________ [***** Start Cisco Security Advisory Document ID: 81825 *****] Cisco Security Advisory: SIP Packet Reloads IOS Devices Not Configured for SIP Document ID: 81825 Advisory ID: cisco-sa-20070131-sip http://www.cisco.com/warp/public/707/cisco-sa-20070131-sip.shtml Revision 1.0 For Public Release 2007 Jan 31 0900 UTC (GMT) -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Contents Summary Affected Products Details Impact Software Version and Fixes Workarounds Obtaining Fixed Software Exploitation and Public Announcements Status of this Notice: INTERIM Distribution Revision History Cisco Security Procedures -------------------------------------------------------------------------------- Summary Cisco devices running IOS which support voice and are not configured for Session Initiated Protocol (SIP) are vulnerable to a crash under yet to be determined conditions, but isolated to traffic destined to Port 5060. SIP is enabled by default on all Advanced images which support voice and do not contain the fix for CSCsb25337. There are no reports of this vulnerability on the devices which are properly configured for SIP processing. Workarounds exist to mitigate the effects of this problem. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa- 20070131-sip.shtml. Affected Products IOS releases that include voice support after 12.3(14)T, 12.3(8)YC1, 12.3(8)YG and all of 12.4 are affected. Please see the fixed software table for a complete list of fixed and vulnerable trains. 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 vulnerable to this issue. IOS image in example: 7200-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 2051E680 *.5060 *.* LISTENThe above lines with *.5060 show that TCP SIP is enabled. Vulnerable Products The following is a list of products that support voice and could be affected by this vulnerability. 815 871 876 877 878 1701 1711 1712 1721 1751 1751-V 1760 1801 1802 1803 1811 1812 1841 2610XM-2611XM 2620XM-2621XM 2650XM-2651XM 2691 2801 2811 2821 2851 3220 3250 3270 3725 3745 3825 3845 7200 7200-NPE-G2 7301 Products Confirmed Not Vulnerable Devices which do not support voice are not affected by this issue. Devices which are properly configured for SIP processing are not affected by this issue. We have no reports of this vunerability on devices that are configured for SIP processing. We also have no reports of affected IOS-XR devices, CatOS devices, or any device which does not run IOS, but can not conclusively rule them out without further testing. This advisory will be updated with more information as it becomes available. Below is an example of a router not vulnerable to this issue. The router in this example is running the fixed release c7200-js-mz.124-5b.bin. 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 0No lines with UDP Port 5060 are shown and UDP SIP is not enabled. In this example UDP port 67 is used by DHCP is not related to this vulnerability. Details SIP is a protocol designed for use in IP phone networks, and is widely used for Voice over Internet Protocol (VOIP) communications worldwide. Cisco devices running an affected image which supports voice services automatically enable SIP, which opens a listening port on UDP port 5060. TCP port 5060 is also opened, but does not appear to be related to the IOS crash detailed in this advisory. CSCsb25337 turns off the listening ports TCP and UDP 5060, and there have been no reports of this vulnerability in any images with this fix integrated. 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. Major Release Availability of Repaired Releases Affected 12.0-Based Release Rebuild Maintenance 12.0 All 12.0 releases are not vulnerable Affected 12.1-Based Release Rebuild Maintenance 12.1 All 12.1 releases are not vulnerable Affected 12.2-Based Release Rebuild Maintenance 12.2 All 12.2 releases are not vulnerable Affected 12.3-Based Release Rebuild Maintenance 12.3 Not vulnerable 12.3B Not vulnerable 12.3BC Not vulnerable 12.3BW Not vulnerable 12.3JA Not vulnerable 12.3JEA Not vulnerable 12.3JEB Not vulnerable 12.3JK Not vulnerable 12.3JX Not vulnerable 12.3T Only 12.3(14)T releases are vulnerable; migrate to 12.4(8) or later. All other 12.3T releases are not vulnerable. 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 Not vulnerable 12.3XI Not vulnerable 12.3XJ Not vulnerable 12.3XK Not vulnerable 12.3XQ Not vulnerable 12.3XR Not vulnerable 12.3XS Not vulnerable 12.3XU Not vulnerable 12.3XW Not vulnerable 12.3XX Not vulnerable 12.3XY Not vulnerable 12.3YA Not vulnerable 12.3YD Not vulnerable 12.3YF Not vulnerable 12.3YG 12.3(8)YG5 12.3YH Not vulnerable 12.3YI Not vulnerable 12.3YJ Not vulnerable 12.3YK Vulnerable; migrate to 12.4(4)T3 or later 12.3YM 12.3(14)YM8 12.3YQ Vulnerable; migrate to 12.4(6)T1 or later 12.3YS Not vulnerable 12.3YT Vulnerable; migrate to 12.4(4)T3 or later 12.3YU Vulnerable; migrate to 12.4(2)XB2 or later 12.3YX 12.3(14)YX2 12.3YZ Not vulnerable Affected 12.4-Based Release Rebuild Maintenance 12.4 12.4(3d) 12.4(5b) 12.4(7a) 12.4(8) 12.4MR 12.4(6)MR 12.4SW All 12.4SW releases are fixed 12.4T 12.4(2)T5 12.4(4)T3 12.4(6)T1 12.4(9)T 12.4XA Vulnerable; migrate to 12.4(6)T1 or later 12.4XB 12.4(4)XB2 12.4XC Vulnerable; contact TAC 12.4XD 12.4(4)XD2 12.4XE All 12.4XE releases are fixed 12.4XG All 12.4XG releases are fixed 12.4XJ All 12.4XJ releases are fixed 12.4XP All 12.4XP releases are fixed 12.4XT All 12.4XT releases are fixed 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. Turn off SIP processing Since this vulnerability is reported only in routers not configured for SIP, the simplest and most effective workaround is to turn SIP processing off. 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)#endControl Plane Policing Cisco IOS software releases 12.0S, 12.2SX, 12.2S, 12.3T, 12.4, and 12.4T support the Control Plane Policing (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 device in accordance with existing security policies and configurations. The following example can be adapted to your network. !-- 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-trafficNote: 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.html , 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 America) +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. Cisco PSIRT is seeing randomly generated traffic which may be unintentionally causing this issue to manifest. Status of this Notice: INTERIM 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. CISCO EXPECTS TO UPDATE THIS DOCUMENT AS NEW INFORMATION BECOMES AVAILABLE. 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 Revision 1.0 2007-January-31 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. [***** End Cisco Security Advisory Document ID: 81825 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Cisco for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. 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Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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