[apops] Cisco Security Advisory: Multiple Crafted IPv6 PacketsCause Relo

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  • Subject: [apops] Cisco Security Advisory: Multiple Crafted IPv6 PacketsCause Reload
  • From: Cisco Systems Product Security Incident Response Team <psirt at cisco dot com>
  • Date: Wed, 26 Jan 2005 17:00:00 +0100
  • Cc: psirt at cisco dot com
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      Cisco Security Advisory: Multiple Crafted IPv6 Packets Cause Reload
      
      Revision 1.0
      
      For Public Release 2005 January 26 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
      =======
      
      Cisco Internetwork Operating System (IOS) Software is vulnerable to a Denial 
      of Service (DoS) attack from crafted IPv6 packets when the device has been
      configured to process IPv6 traffic. This vulnerability requires multiple
      crafted packets to be sent to the device which may result in a reload upon
      successful exploitation.
      
      Cisco has made free software available to address this vulnerability.
      
      There are workarounds available to mitigate the effects.
      
      This issue is tracked by CERT/CC VU#472582
      
      This advisory is available at http://www.cisco.com/warp/public/707/cisco-sa-20050126-ipv6.shtml.
      
      Affected Products
      =================
      
      Vulnerable Products
      
      Only the Cisco devices running IOS and configured for IPv6 are affected. A
      router will display all IPv6 enabled interfaces with the show ipv6 interface
      command.
      
      An empty output or an error message will be displayed if IPv6 is disabled or
      unsupported on the system. In this case the system is not vulnerable.
      
      Sample output of show ipv6 interface command is shown below for a system
      configured for IPv6.
      
            Router#show ipv6 interface
            Serial1/0 is up, line protocol is up
              IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:D200
              Global unicast address(es):
                2001:1:33::3, subnet is 2001:1:33::/64 [TENTATIVE]
              Joined group address(es):
                FF02::1
                FF02::1:FF00:3
                FF02::1:FF00:D200
              MTU is 1500 bytes
              ICMP error messages limited to one every 100 milliseconds
              ICMP redirects are enabled
              ND DAD is enabled, number of DAD attempts: 1
              ND reachable time is 30000 milliseconds
            Router#
      
      
      A router that has IPv6 enabled on a physical or logical interface is vulnerable
      to this issue even if ipv6 unicast-routing is globally disabled. The show ipv6
      interface command can be used to determine whether IPv6 is enabled on any
      interface.
      
      Products Confirmed Not Vulnerable
      
        * Products that are not running Cisco IOS are not affected.
        * Products running any version of Cisco IOS that do not have IPv6 configured
          interfaces are not vulnerable.
      
      No other Cisco products are currently known to be affected by these
      vulnerabilities.
      
      Details
      =======
      
      IPv6 is the "Internet Protocol Version 6", designed by the Internet Engineering
      Task Force (IETF) to replace the current version Internet Protocol, IP Version
      4 (IPv4).
      
      A vulnerability exists in the processing of IPv6 packets that can be exploited
      to cause the reload of a system. Crafted packets received on logical interfaces
      (that is, tunnels including 6to4 tunnels) as well as physical interfaces can
      trigger this vulnerability.
      
      Multiple crafted IPv6 packets need to be sent to exploit this vulnerability.
      Such crafted packets can be sent remotely.
      
      This issue is documented in Cisco bug ID CSCed40933 ( registered customers
      only) .
      
      Impact
      ======
      
      Successful exploitation of this vulnerability results in a reload of the
      device. Repeated exploitation could result in a sustained DoS attack.
      
      Software Versions and Fixes
      ===========================
      
      +-----------------------------------------------------+
      |   Major    |   Availability of Repaired Releases    |
      |  Release   |                                        |
      |------------+----------------------------------------|
      | Affected   |             |         |             |  |
      | 12.0-Based | Rebuild     | Interim | Maintenance |  |
      | Release    |             |         |             |  |
      |------------+-------------+---------+-------------+--|
      |            | 12.0(23)S   |         |             |  |
      |            | and before  |         |             |  |
      |            | are not     |         |             |  |
      |            | vulnerable. |         |             |  |
      |            |-------------+---------+-------------+--|
      |            | 12.0(24)S6  |         |             |  |
      |12.0S       |-------------+---------+-------------+--|
      |            | 12.0(25)S3  |         |             |  |
      |            |-------------+---------+-------------+--|
      |            | 12.0(26)S2  |         |             |  |
      |            |-------------+---------+-------------+--|
      |            | 12.0(27)S1  |         |             |  |
      |            |-------------+---------+-------------+--|
      |            |             |         | 12.0(28)S   |  |
      |------------+-------------+---------+-------------+--|
      | 12.0SX     | 12.0(25)SX8 |         |             |  |
      |------------+-------------------------------------+--|
      | 12.0SZ     | 12.0(27)SZ                          |  |
      |------------+-------------------------------------+--|
      | Affected   |             |         |             |  |
      | 12.2-Based | Rebuild     | Interim | Maintenance |  |
      | Release    |             |         |             |  |
      |------------+-------------------------------------+--|
      |            | 12.2(2)B - 12.2(4)B7 Migrate to     |  |
      |            | 12.2(13)T14 or later                |  |
      |12.2B       |-------------------------------------+--|
      |            | 12.2(4)B8 AND FWD Migrate to 12.3   |  |
      |            | (7)T or later                       |  |
      |------------+-------------------------------------+--|
      | 12.2BC     | Migrate to 12.3(9a)BC               |  |
      |------------+-------------------------------------+--|
      | 12.2BX     | Migrate to 12.3(7)XI1               |  |
      |------------+-------------------------------------+--|
      | 12.2BZ     | Migrate to 12.3(7)XI1               |  |
      |------------+-------------------------------------+--|
      | 12.2CX     | No plan.                            |  |
      |------------+-------------------------------------+--|
      | 12.2CZ     | No plan.                            |  |
      |------------+-------------------------------------+--|
      | 12.2EW     | 12.2(18)EW1                         |  |
      |------------+-------------------------------------+--|
      | 12.2EWA    |             |         | 12.2(20)EWA |  |
      |------------+-------------+---------+-------------+--|
      | 12.2JK     | 12.2(15)JK2 |         |             |  |
      |------------+-------------------------------------+--|
      | 12.2MC     | Migrate to 12.3(11)T                |  |
      |------------+-------------------------------------+--|
      |            | 12.2(14)S9  |         |             |  |
      |            |-------------+---------+-------------+--|
      |            | 12.2(18)S5  |         |             |  |
      |            |-------------+---------+-------------+--|
      | 12.2S      | 12.2(20)S3  |         |             |  |
      |            |-------------+---------+-------------+--|
      |            | 12.2(22)S1  |         |             |  |
      |            |-------------+---------+-------------+--|
      |            |             |         | 12.2(25)S   |  |
      |------------+-------------------------------------+--|
      | 12.2SE     | 12.2(25)SE                          |  |
      |------------+-------------------------------------+--|
      | 12.2SU     | 12.2(14)SU1 |         |             |  |
      |------------+-------------------------------------+--|
      | 12.2SV     | 12.2(23)SV                          |  |
      |------------+-------------------------------------+--|
      | 12.2SW     | 12.2(23)SW                          |  |
      |------------+-------------------------------------+--|
      | 12.2SX     | Migrate to 12.2(17d)SXB2 or later   |  |
      |------------+-------------------------------------+--|
      | 12.2SXA    | Migrate to 12.2(17d)SXB1 or later   |  |
      |------------+-------------------------------------+--|
      | 12.2SXB    | 12.2(17d)   |         |             |  |
      |            | SXB1        |         |             |  |
      |------------+-------------+---------+-------------+--|
      | 12.2SXD    |             |         | 12.2(18)SXD |  |
      |------------+-------------------------------------+--|
      | 12.2SY     | Migrate to 12.2(17d)SXB2 or later   |  |
      |------------+-------------------------------------+--|
      | 12.2SZ     | Migrate to 12.2(20)S4               |  |
      |------------+-------------------------------------+--|
      |            | 12.2(13)T14 |         |             |  |
      |12.2T       |-------------+---------+-------------+--|
      |            | 12.2(15)T12 |         |             |  |
      |------------+-------------------------------------+--|
      | 12.2YT     | Migrate to 12.2(15)T13 or later     |  |
      |------------+-------------------------------------+--|
      | 12.2YU     | Migrate to 12.3(4)T6 or later       |  |
      |------------+-------------------------------------+--|
      | 12.2YV     | Migrate to 12.3(4)T6 or later       |  |
      |------------+-------------------------------------+--|
      | 12.2YZ     | Migrate to 12.2(20)S4 or later      |  |
      |------------+-------------------------------------+--|
      | 12.2ZC     | Migrate to 12.3T or later           |  |
      |------------+-------------------------------------+--|
      | 12.2ZD     | Migrate to 12.3 or later            |  |
      |------------+-------------------------------------+--|
      | 12.2ZE     | Migrate to 12.3 or later            |  |
      |------------+-------------------------------------+--|
      | 12.2ZF     | Migrate to 12.3(4)T6 or later       |  |
      |------------+-------------------------------------+--|
      | 12.2ZG     | Migrate to 12.3(4)T6 or later       |  |
      |------------+-------------------------------------+--|
      | 12.2ZH     | Migrate to 12.3(4)T6 or later       |  |
      |------------+-------------------------------------+--|
      | 12.2ZI     | Migrate to 12.2(18)S or later       |  |
      |------------+-------------------------------------+--|
      | 12.2ZJ     | Migrate to 12.3 or later            |  |
      |------------+-------------------------------------+--|
      | 12.2ZL     | Migrate to 12.3(7)T or later        |  |
      |------------+-------------------------------------+--|
      | 12.2ZN     | Migrate to 12.3(2)T6 or later       |  |
      |------------+-------------------------------------+--|
      | 12.2ZO     | Migrate to 12.2(15)T12 or later     |  |
      |------------+-------------------------------------+--|
      | 12.2ZP     | Migrate to 12.3(8)XY or later       |  |
      |------------+-------------------------------------+--|
      | Affected   |             |         |             |  |
      | 12.3-Based | Rebuild     | Interim | Maintenance |  |
      | Release    |             |         |             |  |
      |------------+-------------+---------+-------------+--|
      |            | 12.3(3f)    |         |             |  |
      |            |-------------+---------+-------------+--|
      |            | 12.3(5c)    |         |             |  |
      |12.3        |-------------+---------+-------------+--|
      |            | 12.3(6a)    |         |             |  |
      |            |-------------+---------+-------------+--|
      |            |             |         | 12.3(9)     |  |
      |------------+-------------+---------+-------------+--|
      | 12.3BC     |             |         | 12.3(9a)BC  |  |
      |------------+-------------+---------+-------------+--|
      | 12.3B      | 12.3(5a)B2  |         |             |  |
      |------------+-------------------------------------+--|
      | 12.3BW     | Migrate to 12.3(5a)B2 or later      |  |
      |------------+-------------------------------------+--|
      | 12.3JA     |             |         | 12.3(2)JA   |  |
      |------------+-------------+---------+-------------+--|
      |            | 12.3(2)T6   |         |             |  |
      |            |-------------+---------+-------------+--|
      | 12.3T      | 12.3(4)T6   |         |             |  |
      |            |-------------+---------+-------------+--|
      |            |             |         | 12.3(7)T    |  |
      |------------+-------------------------------------+--|
      | 12.3XA     | Migrate to 12.3(7)T or later        |  |
      |------------+-------------------------------------+--|
      | 12.3XB     | Migrate to 12.3(8)T or later        |  |
      |------------+-------------------------------------+--|
      | 12.3XC     | Migrate 12.3(2)XC3 or later         |  |
      |------------+-------------------------------------+--|
      | 12.3XD     | 12.3(4)XD4  |         |             |  |
      |------------+-------------------------------------+--|
      | 12.3XE     | 12.3(2)XE1                          |  |
      |------------+-------------------------------------+--|
      | 12.3XF     | Migrate to 12.3(11)T or later       |  |
      |------------+-------------------------------------+--|
      | 12.3XG     | 12.3(4)XG2  |         |             |  |
      |------------+-------------------------------------+--|
      | 12.3XH     | Migrate to 12.3(11)T or later       |  |
      |------------+-------------------------------------+--|
      | 12.3XI     |             |         | 12.3(7)XI   |  |
      |------------+-------------------------------------+--|
      | 12.3XJ     | 12.3(7)XJ                           |  |
      |------------+-------------------------------------+--|
      | 12.3XK     | 12.3(4)XK1  |         |             |  |
      |------------+-------------+---------+-------------+--|
      | 12.3XL     |             |         | 12.3(7)XL   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3XM     |             |         | 12.3(7)XM   |  |
      |------------+-------------------------------------+--|
      | 12.3XN     | Migrate to 12.3(14)T or later       |  |
      |------------+-------------------------------------+--|
      | 12.3XQ     | 12.3(4)XQ                           |  |
      |------------+-------------------------------------+--|
      | 12.3XR     |             |         | 12.3(7)XR   |  |
      |------------+-------------------------------------+--|
      | 12.3XS     | 12.3(7)XS                           |  |
      |------------+-------------------------------------+--|
      | 12.3XT     | 12.3(2)XT                           |  |
      |------------+-------------------------------------+--|
      | 12.3XU     | 12.3(8)XU                           |  |
      |------------+-------------------------------------+--|
      | 12.3XX     |             |         | 12.3(8)XX   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3XW     |             |         | 12.3(8)XW   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3XY     |             |         | 12.3(8)XY   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3XZ     |             |         | 12.3(2)XZ   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3YA     |             |         | 12.3(8)YA   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3YD     |             |         | 12.3(8)YD   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3YE     |             |         | 12.3(4)YE   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3YF     |             |         | 12.3(11)YF  |  |
      |------------+-------------+---------+-------------+--|
      | 12.3YG     |             |         | 12.3(8)YG   |  |
      |------------+-------------+---------+-------------+--|
      | 12.3YH     |             |         | 12.3(8)YH   |  |
      +-----------------------------------------------------+
      
      When considering software upgrades, please also consult http://www.cisco.com/en
      /US/products/products_security_advisories_listing.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
      ========================
      
      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 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 at cisco dot 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 at cisco dot com" or "security-alert at cisco dot 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.
      
      Although it is often difficult to block traffic transiting your network, it is
      possible to identify traffic which should never be allowed to target your
      infrastructure devices and block that traffic at the border of your network.
      Infrastructure access control lists (ACLs) are considered a network security
      best practice and should be considered as a long-term addition to good network
      security as well as a workaround for this specific vulnerability. The white
      paper entitled "Protecting Your Core: Infrastructure Protection Access Control
      Lists", available at http://www.cisco.com/warp/public/707/iacl.html, presents
      guidelines and recommended deployment techniques for infrastructure protection
      ACLs. Exceptions would include any devices which have a legitimate reason to
      access your infrastructure (for example, BGP peers, DNS servers, and so on).
      All other traffic must be able to traverse your network without terminating on
      any of your devices.
      
      Exploitation and Public Announcements
      =====================================
      
      The Cisco PSIRT is not aware of any public announcements or malicious use of
      the vulnerability described in this advisory.
      
      Status of This Notice: FINAL
      ============================
      
      THIS ADVISORY IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF
      GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF
      THE INFORMATION ON THE ADVISORY OR MATERIALS LINKED FROM THE ADVISORY IS AT
      YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS NOTICE AT ANY
      TIME.
      
      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-20050126-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 at cisco dot com
        * first-teams at first dot org (includes CERT/CC)
        * bugtraq at securityfocus dot com
        * vulnwatch at vulnwatch dot org
        * cisco at spot dot colorado dot edu
        * cisco-nsp at puck dot nether dot net
        * full-disclosure at lists dot netsys dot com
        * comp.dcom.sys.cisco at newsgate dot cisco dot 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
      ================
      
      +---------------------------------------------+
      | Revision | 2005-January-26 | Initial public |
      | 1.0      |                 | 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.
      
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