-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: IPv6 Routing Header Vulnerability Advisory ID: cisco-sa-20070124-IOS-IPv6 http://www.cisco.com/warp/public/707/cisco-sa-20070124-IOS-IPv6.shtml Revision 1.0 For Public Release 2007 January 24 1600 UTC (GMT) - ----------------------------------------------------------------------- Summary ======= Processing a specially crafted IPv6 Type 0 Routing header can crash a device running Cisco IOS software. This vulnerability does not affect IPv6 Type 2 Routing header which is used in mobile IPv6. IPv6 is not enabled by default in Cisco IOS. Cisco has made free software available to address this vulnerability for affected customers. There are workarounds available to mitigate the effects of the vulnerability. The workaround depends on if Mobile IPv6 is used and what version on Cisco IOS is being currently used. This vulnerability was initially reported by a customer and further trigger vector was discovered during developing the fix for this vulnerability. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20070124-IOS-IPv6.shtml. Affected Products ================= Devices running Cisco IOS and having IPv6 enabled on, at least, one of their interface may be affected by this vulnerability. Vulnerable Products +------------------ To determine the software running on a Cisco product, log in to the device and issue the "show version" command to display the system banner. Cisco IOS software will identify itself as "Internetwork Operating System Software" or simply "IOS". On the next line of output, the image name will be displayed between parentheses, followed by "Version" and the IOS release name. Other Cisco devices will not have the "show version" command or will give different output. The following example identifies a Cisco product running IOS release 12.4(9.10): Cisco IOS Software, 7200 Software (C7200-JK9O3S-M), Version 12.4(9.10), INTERIM SOFTWARE Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2006 by Cisco Systems, Inc. Compiled Mon 29-May-06 04:42 by prod_rel_team Additional information about Cisco IOS release naming can be found at http://www.cisco.com/warp/public/620/1.html. Products Confirmed Not Vulnerable +-------------------------------- No other Cisco products are known to be vulnerable to the issue described in this Advisory. In particular Cisco IOS XR, Cisco PIX Appliance and Cisco MDS 9000 Series devices are not affected by this vulnerability. Details ======= This vulnerability can be triggered only when Cisco IOS processes specifically crafted IPv6 Type 0 Routing headers, which are used for source routing. Source routing is when an originator node explicitly specifies the exact path that a packet must take to reach the destination. Source routing is enabled by default on Cisco IOS if IPv6 is configured on the device. In order to trigger this vulnerability the packet must be destined to any of the IPv6 addresses defined on the device. The exact packet type is not relevant (e.g., TCP, ICMP, UDP) as the vulnerability is on the IP layer. For this reason care must be taken when implementing a workaround as this vulnerability can be triggered by a spoofed packet. IPv6 multicast packets can not be used to trigger this vulnerability. In addition to Type 0 Routing headers, IPv6 also supports Type 2 Routing that is used in Mobile IPv6 implementation. Type 2 Routing headers can not be used to trigger the vulnerability described in this Advisory. A router running vulnerable Cisco IOS software will process Type 0 Routing headers only if the destination address in the IPv6 packet is one of the IPv6 addresses defined on any of the interfaces. The address may be either a global (i.e., routable), loopback or link local address. Link local addresses are not supposed to be routable and they are valid only among directly connected devices. A device may also be susceptible in scenarios where IPv6 packets are tunneled over IPv4 networks provided that the IPv6 destination address (after de-encapsulation) is one of the IPv6 addresses defined on the device. This is independent of the exact encapsulation method used (e.g., MPLS, GRE or IPv6-in-IPv4). This vulnerability is documented in Cisco Bug IDs CSCsd40334 and CSCsd58381. Vulnerability Scoring Details +---------------------------- Cisco is providing scores for the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). Cisco will provide a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks. Cisco PSIRT will set the bias in all cases to normal. Customers are encouraged to apply the bias parameter when determining the environmental impact of a particular vulnerability. CVSS is a standards based scoring method that conveys vulnerability severity and helps determine urgency and priority of response. Cisco has provided an FAQ to answer additional questions regarding CVSS at http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html. Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at http://intellishield.cisco.com/security/alertmanager/cvss. Cisco Bug IDs: CSCsd40334 - IPv6 packet can cause crash CVSS Base Score: 10 Access Vector: Remote Access Complexity: Low Authentication: Not Required Confidentiality Impact: Complete Integrity Impact: Complete Availability Impact: Complete Impact Bias: Normal CVSS Temporal Score: 8.3 Exploitability: Functional Remediation Level: Official Fix Report Confidence: Confirmed CSCsd58381 - IPv6 routing header limitation CVSS Base Score: 10 Access Vector: Remote Access Complexity: Low Authentication: Not Required Confidentiality Impact: Complete Integrity Impact: Complete Availability Impact: Complete Impact Bias: Normal CVSS Temporal Score: 8.3 Exploitability: Functional Remediation Level: Official Fix Report Confidence: Confirmed Impact ====== Successful exploitation of the vulnerability listed in this Advisory can corrupt some memory structures. In most cases this will cause the affected device to crash and repeated exploitation could result in a sustained DoS attack. However, due to memory corruption, there is a potential to execute an arbitrary code. In the event of a successful remote code execution, device integrity will have been completely compromised. 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. Please note: There are 3 IOS security advisories and one field notice being published on Jan 24th, 2007. Each advisory only lists the releases which fix the issue described in the advisory. A combined software table is available at http://www.cisco.com/warp/public/707/cisco-sa-20070124-bundle.shtml and can be used to choose a software release which fixes all security vulnerabilities published as of January 24th, 2007. The advisories and field notice published on January 24 are listed here. * http://www.cisco.com/warp/public/707/cisco-air-20070124-IOS-ipv6.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-tcp.shtml * http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-ip-option.sht... * http://www.cisco.com/warp/public/770/fn62613.shtml Requests for software rebuilds to include the change for Daylight Savings Time (DST) that will be implemented in March 2007 should be directed through the Technical Assistance Center (TAC) and this advisory should be used as reference. +-----------------------------------------------------------------------------+ | Major Release | Availability of Repaired Releases | |------------------------------+----------------------------------------------| | Affected 12.0-Based Release | Rebuild | Maintenance | |------------------------------+----------------------------------------------| | 12.0 | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0DA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0DB | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0DC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0S | 12.0(32)S3 | | |------------------------------+----------------------------------------------| | 12.0SC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0SL | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0SP | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0ST | Vulnerable; migrate to 12.0(32)S3 or later | |------------------------------+----------------------------------------------| | 12.0SX | Vulnerable for only 12.0(30)SX; contact TAC | |------------------------------+----------------------------------------------| | 12.0SY | | 12.0(32)SY | |------------------------------+----------------------------------------------| | 12.0SZ | Vulnerable; migrate to 12.0(32)S3 or later | |------------------------------+----------------------------------------------| | 12.0T | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0W | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0WC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0WT | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XB | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XD | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XE | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XF | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XG | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XH | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XI | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XJ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XK | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XL | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XM | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XN | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XQ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XR | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XS | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XV | Not vulnerable | |------------------------------+----------------------------------------------| | 12.0XW | Not vulnerable | |------------------------------+----------------------------------------------| | Affected 12.1-Based Release | Rebuild | Maintenance | |------------------------------+----------------------------------------------| | 12.1 | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1AA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1AX | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1AY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1AZ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1CX | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1DA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1DB | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1DC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1E | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EB | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EO | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EU | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EV | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EW | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EX | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1EZ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1T | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XB | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XD | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XE | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XF | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XG | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XH | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XI | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XJ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XL | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XM | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XP | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XQ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XR | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XS | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XT | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XU | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.1XV | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.1XW | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XX | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1XZ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1YA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1YB | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.1YC | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.1YD | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.1YE | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1YF | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1YH | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1YI | Not vulnerable | |------------------------------+----------------------------------------------| | 12.1YJ | Not vulnerable | |------------------------------+----------------------------------------------| | Affected 12.2-Based Release | Rebuild | Maintenance | |------------------------------+----------------------------------------------| | 12.2 | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2B | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2BC | Vulnerable; migrate to 12.3(17b)BC3 or later | |------------------------------+----------------------------------------------| | 12.2BW | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2BY | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2BZ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2CX | Vulnerable; migrate to 12.3(17b)BC3 or later | |------------------------------+----------------------------------------------| | 12.2CY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2CZ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2DA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2DD | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2DX | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2EU | Vulnerable; migrate to 12.2(25)EWA6 or later | |------------------------------+----------------------------------------------| | 12.2EW | Vulnerable; migrate to 12.2(25)EWA6 or later | |------------------------------+----------------------------------------------| | 12.2EWA | 12.2(25)EWA6 | | |------------------------------+----------------------------------------------| | 12.2EX | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2EY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2EZ | Vulnerable; migrate to 12.2(25)SEE1 or later | |------------------------------+----------------------------------------------| | 12.2FX | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2FY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2FZ | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2IXA | Vulnerable; migrate to 12.2(18)IXB or later | |------------------------------+----------------------------------------------| | 12.2IXB | All 12.2IXB releases are fixed | |------------------------------+----------------------------------------------| | 12.2IXC | All 12.2IXC releases are fixed | |------------------------------+----------------------------------------------| | 12.2JA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2JK | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2MB | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2MC | 12.2(15)MC2h | | |------------------------------+---------------------+------------------------| | 12.2S | 12.2(25)S11 | 12.2(30)S | |------------------------------+---------------------+------------------------| | 12.2SB | 12.2(28)SB2 | 12.2(31)SB | |------------------------------+---------------------+------------------------| | 12.2SBC | 12.2(27)SBC4 | | |------------------------------+----------------------------------------------| | 12.2SEA | Vulnerable; migrate to 12.2(25)SEE1 or later | |------------------------------+----------------------------------------------| | 12.2SEB | Vulnerable; migrate to 12.2(25)SEE1 or later | |------------------------------+----------------------------------------------| | 12.2SEC | Vulnerable; migrate to 12.2(25)SEE1 or later | |------------------------------+----------------------------------------------| | 12.2SED | Vulnerable; migrate to 12.2(25)SEE1 or later | |------------------------------+----------------------------------------------| | 12.2SEE | 12.2(25)SEE1 | | |------------------------------+---------------------+------------------------| | 12.2SEF | 12.2(25)SEF1 | | |------------------------------+----------------------------------------------| | 12.2SEG | All 12.2SEG releases are fixed | |------------------------------+----------------------------------------------| | 12.2SG | 12.2(25)SG1 | 12.2(31)SG | |------------------------------+----------------------------------------------| | 12.2SGA | All 12.2SGA releases are fixed | |------------------------------+----------------------------------------------| | 12.2SO | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2SRA | All 12.2SRA releases are fixed | |------------------------------+----------------------------------------------| | 12.2SRB | All 12.2SRB releases are fixed | |------------------------------+----------------------------------------------| | 12.2SU | Vulnerable; migrate to 12.3(14)T7 or later | |------------------------------+----------------------------------------------| | 12.2SV | 12.2(25)SV3 | 12.2(26)SV | |------------------------------+---------------------+------------------------| | 12.2SW | 12.2(25)SW7 | | |------------------------------+----------------------------------------------| | 12.2SX | Vulnerable; migrate to 12.2(18)SXD7a or | | | later | |------------------------------+----------------------------------------------| | 12.2SXA | Vulnerable; migrate to 12.2(18)SXD7a or | | | later | |------------------------------+----------------------------------------------| | 12.2SXB | Vulnerable; migrate to 12.2(18)SXD7a or | | | later | |------------------------------+----------------------------------------------| | 12.2SXD | 12.2(18)SXD7a | | |------------------------------+---------------------+------------------------| | 12.2SXE | 12.2(18)SXE6 | | |------------------------------+---------------------+------------------------| | 12.2SXF | 12.2(18)SXF5 | | |------------------------------+----------------------------------------------| | 12.2SY | Vulnerable; migrate to 12.2(18)SXD7a or | | | later | |------------------------------+----------------------------------------------| | 12.2SZ | Vulnerable; migrate to 12.2(25)S11 or later | |------------------------------+----------------------------------------------| | 12.2T | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2TPC | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.2XA | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XB | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XC | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2XD | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XE | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2XF | Vulnerable; migrate to 12.3(17b)BC3 or later | |------------------------------+----------------------------------------------| | 12.2XG | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XH | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XI | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XJ | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XK | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XL | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XM | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XN | | 12.2(31)XN | |------------------------------+----------------------------------------------| | 12.2XQ | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XR | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2XS | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XT | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XU | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XV | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2XW | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YA | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YB | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2YD | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.2YE | Vulnerable; migrate to 12.2(25)S11 or later | |------------------------------+----------------------------------------------| | 12.2YF | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YG | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2YH | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YJ | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YK | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2YL | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YM | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YN | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YO | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2YP | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2YQ | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YR | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YT | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2YU | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YV | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YW | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YX | Vulnerable; migrate to 12.3(14)T7 or later | |------------------------------+----------------------------------------------| | 12.2YY | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2YZ | Vulnerable; migrate to 12.2(25)S11 or later | |------------------------------+----------------------------------------------| | 12.2ZA | Vulnerable; migrate to 12.2(18)SXD7a or | | | later | |------------------------------+----------------------------------------------| | 12.2ZB | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2ZC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2ZD | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.2ZE | Vulnerable; migrate to 12.3(18) or later | |------------------------------+----------------------------------------------| | 12.2ZF | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2ZG | Not vulnerable | |------------------------------+----------------------------------------------| | 12.2ZH | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.2ZJ | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2ZL | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.2ZN | Vulnerable; migrate to 12.3(4)T13 or later | |------------------------------+----------------------------------------------| | 12.2ZP | Not vulnerable | |------------------------------+----------------------------------------------| | Affected 12.3-Based Release | Rebuild | Maintenance | |------------------------------+---------------------+------------------------| | 12.3 | 12.3(17b) | 12.3(18) | |------------------------------+----------------------------------------------| | 12.3B | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.3BC | 12.3(17b)BC3 | | |------------------------------+----------------------------------------------| | 12.3BW | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.3JA | Not vulnerable | |------------------------------+----------------------------------------------| | 12.3JEA | All 12.3JEA releases are fixed | |------------------------------+----------------------------------------------| | 12.3JEB | All 12.3JEA releases are fixed | |------------------------------+----------------------------------------------| | 12.3JK | Not vulnerable | |------------------------------+----------------------------------------------| | 12.3JX | Not vulnerable | |------------------------------+----------------------------------------------| | | 12.3(4)T13 | | | |---------------------+------------------------| | 12.3T | 12.3(11)T10 | | | |---------------------+------------------------| | | 12.3(14)T7 | | |------------------------------+----------------------------------------------| | 12.3TPC | Not vulnerable | |------------------------------+----------------------------------------------| | 12.3XA | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.3XB | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.3XC | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.3XD | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.3XE | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.3XF | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.3XG | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.3XH | Vulnerable; migrate to 12.3(11)T10 or later | |------------------------------+----------------------------------------------| | 12.3XI | 12.3(7)XI8a | 12.3(7)XI9 | |------------------------------+----------------------------------------------| | 12.3XJ | Vulnerable; migrate to 12.3(14)YX2 or later | |------------------------------+----------------------------------------------| | 12.3XK | Vulnerable; migrate to 12.3(14)T7 or later | |------------------------------+----------------------------------------------| | 12.3XQ | Vulnerable; migrate to 12.4(8) or later | |------------------------------+----------------------------------------------| | 12.3XR | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.3XS | Vulnerable; migrate to 12.4(8) or later | |------------------------------+----------------------------------------------| | 12.3XU | Vulnerable; migrate to 12.4(2)T4 or later | |------------------------------+----------------------------------------------| | 12.3XW | Vulnerable; migrate to 12.3(14)YX2 or later | |------------------------------+----------------------------------------------| | 12.3XX | Vulnerable; migrate to 12.4(8) or later | |------------------------------+----------------------------------------------| | 12.3XY | Not vulnerable | |------------------------------+----------------------------------------------| | 12.3YA | Vulnerable; contact TAC | |------------------------------+----------------------------------------------| | 12.3YD | Vulnerable; migrate to 12.4(2)T4 or later | |------------------------------+----------------------------------------------| | 12.3YF | Vulnerable; migrate to 12.3(14)YX2 or later | |------------------------------+----------------------------------------------| | 12.3YG | Vulnerable; migrate to 12.4(2)T4 or later | |------------------------------+----------------------------------------------| | 12.3YH | Vulnerable; migrate to 12.4(2)T4 or later | |------------------------------+----------------------------------------------| | 12.3YI | Vulnerable; migrate to 12.4(2)T4 or later | |------------------------------+----------------------------------------------| | 12.3YJ | Vulnerable; migrate to 12.4(6)T1 or later | |------------------------------+----------------------------------------------| | 12.3YK | Vulnerable; migrate to 12.4(4)T2 or later | |------------------------------+----------------------------------------------| | 12.3YM | 12.3(14)YM8 | | |------------------------------+----------------------------------------------| | 12.3YQ | Vulnerable; migrate to 12.4(6)T1 or later | |------------------------------+----------------------------------------------| | 12.3YS | Vulnerable; migrate to 12.4(4)T2 or later | |------------------------------+----------------------------------------------| | 12.3YT | Vulnerable; migrate to 12.4(4)T2 or later | |------------------------------+----------------------------------------------| | 12.3YU | Vulnerable; migrate to 12.4(2)XB2 or later | |------------------------------+----------------------------------------------| | 12.3YX | 12.3(14)YX2 | | |------------------------------+---------------------+------------------------| | 12.3YZ | 12.3(11)YZ1 | | |------------------------------+---------------------+------------------------| | Affected 12.4-Based Release | Rebuild | Maintenance | |------------------------------+---------------------+------------------------| | | 12.4(3d) | | | |---------------------+------------------------| | 12.4 | 12.4(5b) | | | |---------------------+------------------------| | | 12.4(7a) | 12.4(8) | |------------------------------+----------------------------------------------| | 12.4MR | Not vulnerable | |------------------------------+----------------------------------------------| | 12.4SW | All 12.4SW releases are fixed | |------------------------------+----------------------------------------------| | | 12.4(2)T4 | | | |---------------------+------------------------| | 12.4T | 12.4(4)T2 | | | |---------------------+------------------------| | | 12.4(6)T1 | 12.4(9)T | |------------------------------+----------------------------------------------| | 12.4XA | Vulnerable; migrate to 12.4(6)T1 or later | |------------------------------+----------------------------------------------| | 12.4XB | 12.4(2)XB2 | | |------------------------------+---------------------+------------------------| | 12.4XC | 12.4(4)XC5 | | |------------------------------+---------------------+------------------------| | 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 =========== The workaround consists of filtering packets that contain Type 0 Routing header(s). Special attention must be paid not to filter packets with Type 2 Routing headers as that would break Mobile IPv6 deployment. Depending on what Cisco IOS software release is used and if Mobile IPv6 is deployed or not we have the following workarounds. As any packet type can be used to trigger this vulnerability the care must be taken when implementing a workaround to account for a spoofed packet. 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-20070124-IOS-IPv6.shtml Mobile IPv6 is not deployed +-------------------------- For IOS releases before 12.3(4)T the workaround is to use ACLs to filter all packets that contain Routing headers. This method can not distinguish between Type 0 and Type 2 Routing headers so it is not suitable if Mobile IPv6 is deployed. The following example shows how to configure such ACLs. Router(config)#ipv6 access-list deny-sourcerouted Router(config-ipv6-acl)#deny ipv6 any <myaddress1> routing Router(config-ipv6-acl)#deny ipv6 any <myaddress2> routing Router(config-ipv6-acl)#permit ipv6 any any Router(config-ipv6-acl)#exit Router(config)#interface Ethernet0 Router(config-if)#ipv6 traffic-filter deny-sourcerouted in In this example <myaddressX> is an IPv6 address. One example of such address is 2600:dead:beef:cafe:0:1:0:1111. The ACL must be applied to all interfaces and all IPv6 addresses that are configured. If an interface has more than one IPv6 address configured then all addresses must be covered by the ACLs. This also includes all loopback and "link local" addresses for each interface. The alternative of enumerating all IPv6 addresses is to use statement "deny ipv6 any any routing". While that simplifies the resulting ACL it will also filter all transit IPv6 traffic with Routing headers 0 and 2. The example where all configured IPv6 addresses are enumerated will not affect transit traffic. This comment is applicable to all other examples in this Advisory. Starting from the IOS release 12.2(15)T a new command "ipv6 source-route" was introduced. If applied, it will block any IPv6 packet with any IPv6 routing headers (both types 0 and 2). The configuration is given in the following example. Router(config)#no ipv6 source-route This is a global command and it applies to all interfaces. The command is applicable on all defined IPv6 addresses, including the link local and loopback address, and on all interfaces. Mobile IPv6 is deployed +---------------------- There is no workaround if you are running a Cisco IOS release prior to 12.4(2)T. In IOS 12.4(2)T a new keyword "routing-type" is added to IPv6 ACLs. It can be used to selectively permit or deny specific routing types. Router(config)#ipv6 access-list deny-sourcerouted Router(config-ipv6-acl)#deny ipv6 any <myaddress1> routing-type 0 Router(config-ipv6-acl)#permit ipv6 any any Router(config)#interface Ethernet0 Router(config-if)#ipv6 source-route Router(config-if)#ipv6 traffic-filter deny-sourcerouted in The filter must be applied to all interfaces that have IPv6 configured. 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 ===================================== The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory. This vulnerability was initially reported to Cisco by Arnaud Ebalard from EADS Corporate Research Center. An additional vector to trigger it was discovered internally while fixing the vulnerability. Status of this Notice: FINAL ============================ THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. A stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors. Distribution ============ This advisory is posted on Cisco's worldwide website at: http://www.cisco.com/warp/public/707/cisco-sa-20070124-IOS-IPv6.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@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 ================ +----------------------------------------+ | 1.0 | 2007-January-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.h.... This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt. - ----------------------------------------------------------------------- All contents are Copyright 1992-2007 Cisco Systems, Inc. All rights reserved. - ----------------------------------------------------------------------- Updated: Jan 24, 2007 Document ID: 72372 - ----------------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFFt4q78NUAbBmDaxQRAnmUAKCddmt7R/tv6za5p5uaXzv3nJGAXQCeIh+Q VY3aC/IEoqWog0b4v3ji+is= =lzrx -----END PGP SIGNATURE-----