[apops] Cisco Security Advisory: Crafted TCP Packet Can Cause Denial of

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  • Subject: [apops] Cisco Security Advisory: Crafted TCP Packet Can Cause Denial of Service
  • From: Cisco Systems Product Security Incident Response Team <psirt at cisco dot com>
  • Date: Wed, 24 Jan 2007 16:12:00 -0000
  • Cc: psirt at cisco dot com
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      Cisco Security Advisory: Crafted TCP Packet Can Cause Denial of
      Service
      
      Advisory ID: cisco-sa-20070124-crafted-tcp
      
      http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-tcp.shtml
      
      Revision 1.0
      
      For Public Release 2007 January 24 1600 UTC (GMT)
      
      - ---------------------------------------------------------------------
      
      Summary
      =======
      
      The Cisco IOS Transmission Control Protocol (TCP) listener in certain
      versions of Cisco IOS software is vulnerable to a
      remotely-exploitable memory leak that may lead to a denial of service
      condition.
      
      This vulnerability only applies to traffic destined to the Cisco IOS
      device. Traffic transiting the Cisco IOS device will not trigger this
      vulnerability.
      
      Cisco has made free software available to address this vulnerability
      for affected customers.
      
      This issue is documented as Cisco bug ID CSCek37177.
      
      There are workarounds available to mitigate the effects of the
      vulnerability.
      
      This advisory is posted at
      http://www.cisco.com/warp/public/707/cisco-sa-20070124-crafted-tcp.shtml
      
      Affected Products
      =================
      
      Vulnerable Products
      +------------------
      
      This issue affects all Cisco devices running Cisco IOS software. To
      be affected, devices must be configured to process Internet Protocol
      version 4 (IPv4) packets and receive TCP packets. Devices which run
      only Internet Protocol version 6 (IPv6) are not affected.
      
      This vulnerability is present in all unfixed versions of Cisco IOS
      software, including versions 9.x, 10.x, 11.x and 12.x.
      
      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 Cisco IOS
      release 12.2(14)S16 with an installed image name of C7200-IS-M:
      
          Cisco Internetwork Operating System Software 
          IOS (tm) 7200 Software (C7200-IS-M), Version 12.2(14)S16, RELEASE SOFTWARE (fc1)
          
      
      The release train label is "12.2".
      
      The next example shows a product running IOS release 12.3(7)T12 with
      an image name of C7200-IK9S-M:
      
          Cisco IOS Software, 7200 Software (C7200-IK9S-M), Version 12.3(7)T12, RELEASE SOFTWARE  (fc1)
          
      
      Additional information about Cisco IOS Banners is available at:
      
      http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_white_paper09186a008018305e.shtml#3
      
      Products Confirmed Not Vulnerable
      +--------------------------------
      Cisco products that do not run IOS are unaffected by this
      vulnerability.
      
      Cisco IOS-XR is not affected.
      
      No other Cisco products are currently known to be affected by this
      vulnerability.
      
      Details
      =======
      
      TCP is the transport layer protocol designed to provide
      connection-oriented, reliable delivery of a data stream. To
      accomplish this, TCP uses a mixture of flags to indicate state and
      sequence numbers to identify the order in which the packets are to be
      reassembled. TCP also provides a number, called an acknowledgement
      number, that is used to indicate the sequence number of the next
      packet expected. The full specification of the TCP protocol can be
      found at http://www.ietf.org/rfc/rfc0793.txt
      
      Cisco IOS devices that are configured to receive TCP packets are
      exposed to this issue. This Advisory does not apply to traffic that
      is transiting the device.
      
      Certain crafted packets destined to an IPv4 address assigned to a
      physical or virtual interface on a Cisco IOS device may cause the
      device to leak a small amount of memory. Over time, such a memory
      leak may lead to memory exhaustion and potentially degraded service.
      
      Although this is an issue with TCP, it is not required to complete
      the TCP 3-way handshake in order for the memory leak to be triggered.
      Therefore, TCP packets with a spoofed source address may trigger the
      leak.
      
      The following document contains additional information on how to
      identify if your router is suffering from a memory leak in Processor
      memory:
      
      http://www.cisco.com/warp/public/63/mallocfail.shtml#tshoot2
      
      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:
      http://intellishield.cisco.com/security/alertmanager/cvss
      
      Cisco Bug IDs:                    
                                        
      CSCek37177                        
                                        
      CVSS Base Score: 3.3              
          Access Vector: Remote         
          Access Complexity: Low        
          Authentication: Not Required  
          Confidentiality Impact: None  
          Integrity Impact: None        
          Availability Impact: Complete 
          Impact Bias: Normal           
      
      CVSS Temporal Score: 2.7          
          Exploitability: Functional    
          Remediation Level: Official Fix
          Report Confidence: Confirmed
      
      Impact
      ======
      
      Successful exploitation of the vulnerability may result in a small
      amount of processor memory to leak, which may lead to degraded
      service. This issue will not resolve over time, and will require a
      device reset to recover the leaked memory.
      
      This vulnerability only applies to traffic destined to the Cisco IOS
      device. Traffic transiting the device will not trigger this issue.
      
      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    |             Availability of Repaired Releases             |
      |  Release   |                                                           |
      |------------+-----------------------------------------------------------|
      | Affected   |                            |                              |
      | 12.0-Based | Rebuild                    | Maintenance                  |
      | Release    |                            |                              |
      |------------+-----------------------------------------------------------|
      | 12.0       | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0DA     | Vulnerable; migrate to 12.2(10)DA5 or later               |
      |------------+-----------------------------------------------------------|
      | 12.0DB     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0DC     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      |            | 12.0(31)S6                 |                              |
      |12.0S       |----------------------------+------------------------------|
      |            | 12.0(32)S4                 |                              |
      |------------+-----------------------------------------------------------|
      | 12.0SC     | Vulnerable; migrate to 12.3(13a)BC6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.0SL     | Vulnerable; migrate to 12.0(31)S6 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0SP     | Vulnerable; migrate to 12.0(31)S6 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0ST     | Vulnerable; migrate to 12.0(31)S6 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0SX     | 12.0(25)SX11               |                              |
      |------------+----------------------------+------------------------------|
      | 12.0SY     |                            | 12.0(32)SY                   |
      |------------+-----------------------------------------------------------|
      | 12.0SZ     | Vulnerable; migrate to 12.0(31)S6 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0T      | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0W      | Not vulnerable                                            |
      |------------+-----------------------------------------------------------|
      | 12.0WC     | 12.0(5)WC15                |                              |
      |------------+-----------------------------------------------------------|
      | 12.0WT     | Not vulnerable                                            |
      |------------+-----------------------------------------------------------|
      | 12.0XA     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XB     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XC     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XD     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XE     | Vulnerable; migrate to 12.1(26)E7 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0XF     | Not vulnerable                                            |
      |------------+-----------------------------------------------------------|
      | 12.0XG     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XH     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XI     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XJ     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XK     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XL     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XM     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XN     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XQ     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XR     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XS     | Vulnerable; migrate to 12.1(26)E7 or later                |
      |------------+-----------------------------------------------------------|
      | 12.0XV     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.0XW     | Not vulnerable                                            |
      |------------+-----------------------------------------------------------|
      | Affected   |                            |                              |
      | 12.1-Based | Rebuild                    | Maintenance                  |
      | Release    |                            |                              |
      |------------+-----------------------------------------------------------|
      | 12.1       | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1 AA    | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1 AX    | Vulnerable; migrate to 12.2(25)EY4 or later               |
      |------------+-----------------------------------------------------------|
      | 12.1 AY    | Vulnerable; migrate to 12.1(22)EA8 or later               |
      |------------+-----------------------------------------------------------|
      | 12.1 AZ    | Vulnerable; migrate to 12.1(22)EA8 or later               |
      |------------+-----------------------------------------------------------|
      | 12.1 CX    | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1 DA    | Vulnerable; migrate to 12.2(10)DA5 or later               |
      |------------+-----------------------------------------------------------|
      | 12.1 DB    | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.1 DC    | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      |            | 12.1(26)E7                 |                              |
      |12.1E       |----------------------------+------------------------------|
      |            | 12.1(27b)E1                |                              |
      |------------+----------------------------+------------------------------|
      | 12.1EA     | 12.1(22)EA8                |                              |
      |------------+-----------------------------------------------------------|
      | 12.1EB     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.1EC     | Vulnerable; migrate to 12.3(13a)BC6 or later              |
      |------------+-----------------------------------------------------------|
      |            | 12.1(19)EO6; available on  |                              |
      | 12.1EO     | 31-Jan-07                  |                              |
      |            |----------------------------+------------------------------|
      |            | 12.1(20)EO3                |                              |
      |------------+-----------------------------------------------------------|
      | 12.1EU     | Vulnerable; migrate to 12.2(25)EWA6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.1EV     | Vulnerable; migrate to 12.2(27)SV4 or later               |
      |------------+-----------------------------------------------------------|
      | 12.1EW     | Vulnerable; migrate to 12.2(25)EWA6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.1EX     | Vulnerable; migrate to 12.1(26)E7 or later                |
      |------------+-----------------------------------------------------------|
      | 12.1EY     | Vulnerable; migrate to 12.1(26)E7 or later                |
      |------------+-----------------------------------------------------------|
      | 12.1EZ     | Vulnerable; migrate to 12.1(26)E7 or later                |
      |------------+-----------------------------------------------------------|
      | 12.1T      | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XA     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XB     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XC     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XD     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XE     | Vulnerable; migrate to 12.1(26)E7 or later                |
      |------------+-----------------------------------------------------------|
      | 12.1XF     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XG     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XH     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XI     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XJ     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XL     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XM     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XP     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XQ     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XR     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XS     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XT     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XU     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XV     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XW     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XX     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XY     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1XZ     | Vulnerable; migrate to 12.2(37) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YA     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YB     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YC     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YD     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YE     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YF     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YH     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YI     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.1YJ     | Vulnerable; migrate to 12.1(22)EA8 or later               |
      |------------+-----------------------------------------------------------|
      | Affected   |                            |                              |
      | 12.2-Based | Rebuild                    | Maintenance                  |
      | Release    |                            |                              |
      |------------+----------------------------+------------------------------|
      | 12.2       |                            | 12.2(37)                     |
      |------------+-----------------------------------------------------------|
      | 12.2B      | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2BC     | Vulnerable; migrate to 12.3(13a)BC6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2BW     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2BY     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2BZ     | Vulnerable; migrate to 12.3(7)XI8 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2CX     | Vulnerable; migrate to 12.3(13a)BC6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2CY     | Vulnerable; migrate to 12.3(13a)BC6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2CZ     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      |            | 12.2(10)DA5                |                              |
      |12.2DA      |----------------------------+------------------------------|
      |            | 12.2(12)DA10               |                              |
      |------------+-----------------------------------------------------------|
      | 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     | 12.2(25)EX1                |                              |
      |------------+----------------------------+------------------------------|
      | 12.2EY     | 12.2(25)EY4                |                              |
      |------------+-----------------------------------------------------------|
      | 12.2EZ     | Vulnerable; migrate to 12.2(25)SEE1 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2FX     | Vulnerable; migrate to 12.2(25)SEE1 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2FY     | Vulnerable; migrate to 12.2(25)SEE1 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2FZ     | All 12.2FZ releases are fixed                             |
      |------------+-----------------------------------------------------------|
      | 12.2IXA    | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.2IXB    | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.2IXC    | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.2JA     | Vulnerable; migrate to 12.3(8)JA2 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2JK     | Vulnerable; migrate to 12.4(4)T4 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.2MB     | Vulnerable; migrate to 12.2(25)SW8 or later               |
      |------------+-----------------------------------------------------------|
      | 12.2MC     | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.2S      | 12.2(25)S12; Available     |                              |
      |            | 12-Feb-07                  |                              |
      |------------+----------------------------+------------------------------|
      | 12.2SB     | 12.2(28)SB2                | 12.2(31)SB                   |
      |------------+----------------------------+------------------------------|
      | 12.2SBC    | 12.2(27)SBC5               |                              |
      |------------+----------------------------+------------------------------|
      | 12.2SE     |                            | 12.2(35)SE                   |
      |------------+-----------------------------------------------------------|
      | 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     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.2SGA    | All 12.2SGA releases are fixed                            |
      |------------+-----------------------------------------------------------|
      | 12.2SO     | 12.2(18)SO7                |                              |
      |------------+-----------------------------------------------------------|
      | 12.2SRA    | All 12.2SRA releases are fixed                            |
      |------------+-----------------------------------------------------------|
      | 12.2SRB    | All 12.2SRB releases are fixed                            |
      |------------+-----------------------------------------------------------|
      | 12.2SU     | Vulnerable; migrate to 12.4(8) or later                   |
      |------------+-----------------------------------------------------------|
      |            | 12.2(27)SV4                |                              |
      |            |----------------------------+------------------------------|
      | 12.2SV     | 12.2(28)SV1                |                              |
      |            |----------------------------+------------------------------|
      |            | 12.2(29)SV1                |                              |
      |------------+----------------------------+------------------------------|
      | 12.2SW     | 12.2(25)SW8                |                              |
      |------------+-----------------------------------------------------------|
      | 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)S12 or later; Available    |
      |            | 12-Feb-07                                                 |
      |------------+-----------------------------------------------------------|
      | 12.2T      | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2TPC    | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.2XA     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XB     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XC     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2XD     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XE     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XF     | Vulnerable; migrate to 12.3(13a)BC6 or later              |
      |------------+-----------------------------------------------------------|
      | 12.2XG     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XH     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XI     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XJ     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XK     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XL     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XM     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XN     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XQ     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XR     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XS     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XT     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XU     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XV     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2XW     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YA     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YB     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YC     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YD     | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.2YE     | Vulnerable; migrate to 12.2(25)S12 or later; Available    |
      |            | 12-Feb-07                                                 |
      |------------+-----------------------------------------------------------|
      | 12.2YF     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YG     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YH     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YJ     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YK     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 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     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2YQ     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2YR     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2YS     | Not vulnerable                                            |
      |------------+-----------------------------------------------------------|
      | 12.2YT     | Vulnerable; migrate to 12.3(19) 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 12.4(8) or later                   |
      |------------+-----------------------------------------------------------|
      | 12.2YY     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2YZ     | Vulnerable; migrate to 12.2(25)S12 or later; Available    |
      |            | 12-Feb-07                                                 |
      |------------+-----------------------------------------------------------|
      | 12.2ZA     | Vulnerable; migrate to 12.2(18)SXD7a or later             |
      |------------+-----------------------------------------------------------|
      | 12.2ZB     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2ZC     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2ZD     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.2ZE     | Vulnerable; migrate to 12.3(19) or later                  |
      |------------+-----------------------------------------------------------|
      | 12.2ZF     | Vulnerable; migrate to 12.3(4)T13 or later                |
      |------------+-----------------------------------------------------------|
      | 12.2ZG     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 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     | Vulnerable; migrate to 12.4(8) or later                   |
      |------------+-----------------------------------------------------------|
      | Affected   |                            |                              |
      | 12.3-Based | Rebuild                    | Maintenance                  |
      | Release    |                            |                              |
      |------------+----------------------------+------------------------------|
      | 12.3       | 12.3(10f)                  | 12.3(19)                     |
      |------------+-----------------------------------------------------------|
      | 12.3B      | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      |            | 12.3(13a)BC6               |                              |
      |12.3BC      |----------------------------+------------------------------|
      |            | 12.3(17a)BC2               |                              |
      |------------+-----------------------------------------------------------|
      | 12.3BW     | Vulnerable; migrate to 13.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3JA     | 12.3(8)JA2                 |                              |
      |------------+-----------------------------------------------------------|
      | 12.3JEA    | All 12.3JEA releases are fixed                            |
      |------------+-----------------------------------------------------------|
      | 12.3JEB    | All 12.3JEB releases are fixed                            |
      |------------+-----------------------------------------------------------|
      | 12.3JK     | 12.3(2)JK2                 |                              |
      |------------+----------------------------+------------------------------|
      | 12.3JX     | 12.3(7)JX4                 | 12.3(11)JX                   |
      |------------+----------------------------+------------------------------|
      |            | 12.3(4)T13                 |                              |
      |12.3T       |----------------------------+------------------------------|
      |            | 12.3(11)T11                |                              |
      |------------+-----------------------------------------------------------|
      | 12.3TPC    | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3XA     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3XB     | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3XC     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3XD     | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3XE     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3XF     | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3XG     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3XH     | Vulnerable; migrate to 12.3(11)T11 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3XI     | 12.3(7)XI8                 |                              |
      |------------+-----------------------------------------------------------|
      | 12.3XJ     | Vulnerable; migrate to 12.3(14)YX2 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3XK     | Vulnerable; migrate to 12.4(8) 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)T5 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     | Vulnerable; migrate to 12.4(8) or later                   |
      |------------+-----------------------------------------------------------|
      | 12.3YA     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3YD     | Vulnerable; migrate to 12.4(2)T5 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YF     | Vulnerable; migrate to 12.3(14)YX2 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3YG     | Vulnerable; migrate to 12.4(2)T5 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YH     | Vulnerable; migrate to 12.4(2)T5 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YI     | Vulnerable; migrate to 12.4(2)T5 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YJ     | Vulnerable; migrate to 12.3(14)YQ8 or later               |
      |------------+-----------------------------------------------------------|
      | 12.3YK     | Vulnerable; migrate to 12.4(4)T4 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YM     | 12.3(14)YM8                |                              |
      |------------+----------------------------+------------------------------|
      | 12.3YQ     | 12.3(14)YQ8                |                              |
      |------------+-----------------------------------------------------------|
      | 12.3YS     | Vulnerable; migrate to 12.4(4)T4 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YT     | Vulnerable; migrate to 12.4(4)T4 or later                 |
      |------------+-----------------------------------------------------------|
      | 12.3YU     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.3YX     | 12.3(14)YX2                |                              |
      |------------+----------------------------+------------------------------|
      | 12.3YZ     | 12.3(11)YZ1                |                              |
      |------------+----------------------------+------------------------------|
      | Affected   |                            |                              |
      | 12.4-Based | Rebuild                    | Maintenance                  |
      | Release    |                            |                              |
      |------------+----------------------------+------------------------------|
      |            | 12.4(3e)                   |                              |
      |12.4        |----------------------------+------------------------------|
      |            | 12.4(7b)                   | 12.4(8)                      |
      |------------+----------------------------+------------------------------|
      | 12.4MR     | 12.4(6)MR1                 |                              |
      |------------+-----------------------------------------------------------|
      | 12.4SW     | All 12.4SW releases are fixed                             |
      |------------+-----------------------------------------------------------|
      |            | 12.4(2)T5                  |                              |
      |            |----------------------------+------------------------------|
      | 12.4T      | 12.4(4)T4                  |                              |
      |            |----------------------------+------------------------------|
      |            | 12.4(6)T3                  | 12.4(9)T                     |
      |------------+-----------------------------------------------------------|
      | 12.4XA     | Vulnerable; migrate to 12.4(6)T3                          |
      |------------+-----------------------------------------------------------|
      | 12.4XB     | Vulnerable; contact TAC                                   |
      |------------+-----------------------------------------------------------|
      | 12.4XC     | 12.4(4)XC3                 |                              |
      |------------+----------------------------+------------------------------|
      | 12.4XD     | 12.4(4)XD4                 |                              |
      |------------+-----------------------------------------------------------|
      | 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-20070124-crafted-tcp.shtml
      
      Note: Configuring VTY access-class filters is not an effective
      mitigation strategy for this vulnerability.
      
      Infrastructure ACLs (iACL)
      +-------------------------
      
      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 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 ACL example shown below should
      be included as part of the deployed infrastructure access-list which
      will protect all devices with IP addresses in the infrastructure IP
      address range.
      
      A sample access list for devices running Cisco IOS is below:
      
          !--- Permit TCP services from trust hosts destined 
          !--- to infrastructure addresses.
          
          access-list 150 permit tcp TRUSTED_HOSTS MASK INFRASTRUCTURE_ADDRESSES MASK
          
          !--- Deny TCP packets from all other sources destined to infrastructure addresses.
          
          access-list 150 deny   tcp any INFRASTRUCTURE_ADDRESSES MASK
          
          !--- Permit all other traffic to transit the device.
          
          access-list 150 permit IP any any
          
          interface serial 2/0
            ip access-group 150 in
          
      
      The white paper entitled "Protecting Your Core: Infrastructure
      Protection Access Control Lists" presents guidelines and recommended
      deployment techniques for infrastructure protection access lists.
      This white paper can be obtained here:
      http://www.cisco.com/warp/public/707/iacl.html
      
      Receive ACLs (rACL)
      +------------------
      
      For distributed platforms, Receive ACLs may be an option starting in
      Cisco IOS Software Versions 12.0(21)S2 for the 12000 (GSR), 12.0(24)S
      for the 7500, and 12.0(31)S for the 10720. The Receive ACL protects
      the device from harmful traffic before the traffic can impact the
      route processor. Receive ACLs are designed to only protect the device
      on which it is configured. On the 12000, transit traffic is never
      affected by a receive ACL. Because of this, the destination IP
      address "any" used in the example ACL entries below only refer to the
      router's own physical or virtual IP addresses. On the 7500 and 10720,
      transit traffic with IP options set will be subject to the Receive
      ACL and permitted or denied accordingly. Receive 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 "GSR:
      Receive Access Control Lists" will help you identify and allow
      legitimate traffic to your device and deny all unwanted packets: 
      http://www.cisco.com/warp/public/707/racl.html
      
      The following is the receive path ACL written to permit this type of
      traffic from trusted hosts:
      
          !--- Permit tcp services from trusted hosts allowed to the RP.
                                                          
          access-list 151 permit tcp TRUSTED_ADDRESSES MASK any 
          
          !--- Deny tcp services from all other sources to the RP.
                                                                   
          access-list 151 deny   tcp any any                       
          
          !--- Permit all other traffic to the RP.
                                                                                   
          access-list 151 permit ip any any                                            
          
          !--- Apply this access list to the 'receive' path.
          
          ip receive access-list 151
          
      
      Control Plane Policing (CoPP)
      +----------------------------
      
      The Control Plane Policing (CoPP) feature may be used to mitigate
      this vulnerability. In the following example, only TCP traffic from
      trusted hosts and with 'receive' destination IP addresses is
      permitted to reach the route processor (RP). All other 'transit' IP
      traffic is unaffected.
      
      It should be noted that dropping traffic from unknown or untrusted IP
      addresses may affect hosts with dynamically assigned IP addresses
      from connecting to the Cisco IOS device.
      
          access-list 152 deny   tcp TRUSTED_ADDRESSES MASK any
          access-list 152 permit tcp any any
          access-list 152 deny  ip any any
          !
          class-map match-all permit-tcp-class
           match access-group 152
          !
          !
          policy-map permit-tcp-policy
           class permit-tcp-class
            drop
          !
          control-plane
           service-policy input permit-tcp-policy
          
      
      In the above CoPP example, the ACL entries that match the 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 are not affected by the policy-map drop function.
      
      Please note that in the 12.2S and 12.0S Cisco IOS trains the
      policy-map syntax is different:
      
          policy-map permit-tcp-policy                                   
           class class permit-tcp-class                                  
            police 32000 1500 1500 conform-action drop exceed-action drop
          
      
      CoPP is available in Cisco IOS release trains 12.0S, 12.2SX, 12.2S,
      12.3T, 12.4, and 12.4T.
      
      Additional information on the configuration and use of the CoPP
      feature can be found at the following URL:
      
      http://www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_white_paper09186a0080211f39.shtml
      
      Anti-spoofing
      +------------
      
      The Unicast Reverse Path Forwarding (Unicast RPF or uRPF) feature
      helps to mitigate problems that are caused by spoofed IP source
      addresses. It is available on Cisco routers and firewalls. For
      further details, please refer to:
      
      http://www.cisco.com/en/US/partner/products/ps6441/products_command_reference_chapter09186a00804ae49f.html#wp1229984
      
      By enabling Unicast Reverse Path Forwarding (uRPF), all spoofed
      packets will be dropped at the first device. To enable uRPF, use the
      following commands.
      
          router(config)# ip cef                                      
          router(config)# interface interface #                       
          router(config-if)# ip verify unicast source reachable-via rx    
      
      BGP and BTSH/GTSM
      +----------------
      
      Depending on your release of software, it may be possible to protect
      your BGP sessions from this memory leak. With the introduction of
      CSCee73956, Cisco IOS has improved support for BTSH (BGP TTL Security
      Hack) to reduce, if not eliminate a risk of a memory leak due to this
      vulnerability. This functionality is also known as GTSM (Generalized
      TTL Security Mechanism) and documented in RFC 3682. This section
      refers to GTSM as applied to eBGP sessions only.
      
      Releases of Cisco IOS that contain CSCee73956 are protected from this
      attack against the BGP port (TCP port 179) only. Other ports should
      be protected accordingly.
      
      BTSH is not supported for iBGP sessions. BTSH was first introduced in
      Cisco IOS in 12.0(27)S, 12.3(7)T and 12.2(25)S. Note that the BTSH
      feature prior to CSCee73956 will not protect against this
      vulnerability.
      
      For more information on BTSH, please see:
      http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_7/gt_btsh.htm
      
      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 at cisco dot com" or "security-alert at cisco dot 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 at cisco dot 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 discovered by Cisco during our internal
      testing process.
      
      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-crafted-tcp.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
        * 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.grok dot org dot uk
        * comp.dcom.sys.cisco at newsgate dot cisco dot 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
      ================
      
      +---------------------------------------+
      |     |                 | Initial       |
      | 1.0 | 2007-January-24 | 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
      
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