Cisco IOS Software Network Address Translation Vulnerability

Summary

• The Cisco IOS Software implementation of the virtual routing and forwarding (VRF) aware network address translation (NAT) feature contains a vulnerability when translating IP packets that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

  Cisco has released software updates that address this vulnerability. Workarounds that mitigate this vulnerability are not available.

  This advisory is available at the following link:

  http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130327-nat

  Note: The March 27, 2013, Cisco IOS Software Security Advisory bundled publication includes seven Cisco Security Advisories. All advisories address vulnerabilities in Cisco IOS Software. Each Cisco IOS Software Security Advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all Cisco IOS Software vulnerabilities in the March 2013 bundled publication.

  Individual publication links are in "Cisco Event Response: Semiannual Cisco IOS Software Security Advisory Bundled Publication" at the following link:

  http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_mar13.html

Affected Products

• This vulnerability affects devices that are running affected versions of Cisco IOS Software and have a VRF-aware NAT configuration.

  Vulnerable Products

  Cisco devices that are running Cisco IOS Software are vulnerable when they are configured for VRF-aware NAT.

  There are two methods to determine whether a device is configured for VRF-aware NAT:

  • Determine whether VRF-aware NAT commands are included in the device configuration.
  • Determine whether VRF-aware NAT is active on a device.

  The preferred method to verify whether NAT is enabled on a Cisco IOS device is to inspect the device configuration to determine whether VRF-aware NAT commands are included in it.
  

  Determine Whether VRF-aware NAT Commands are Included in the Device Configuration

  To determine whether NAT has been enabled in the Cisco IOS Software configuration, at least one ip nat global configuration command must have a vrf keyword. The show configuration | include ip nat .* vrf .* command can be used to determine whether VRF-aware NAT is present in the configuration, as illustrated in the following example:

  Router> show running-config | include ip nat .* vrf .*
  ip nat inside source static 192.168.121.113 2.2.2.1 vrf VRF-Red
  Router>
  

  Determine Whether VRF-aware NAT is Active on a Device

  The administrator can determine whether VRF-aware NAT is enabled on a Cisco IOS device by checking that both the NAT and VRF features are active.

  Checking for an Active NAT Feature

  First, enter the show ip nat statistics command. If NAT is active, the sections Outside interfaces and Inside interfaces will each include at least one interface. The following example shows a device on which the NAT feature is active:

  
  

  Router# show ip nat statistics
  
  Total translations: 2 (0 static, 2 dynamic; 0 extended)
  Outside interfaces: Serial0
  Inside interfaces: Ethernet1
  Hits: 135  Misses: 5
  Expired translations: 2
  Dynamic mappings:
  -- Inside Source
  access-list 1 pool mypool refcount 2
   pool mypool: netmask 255.255.255.0
          start 192.168.10.1 end 192.168.10.254
          type generic, total addresses 14, allocated 2 (14%), misses 0

  
  Depending on the Cisco IOS Software release, the interface lists can be in the lines following the Outside interfaces and Inside interfaces lines.

  In releases that support the section filter on show commands, the administrator can determine whether NAT is active by using the show ip nat statistics | section interfaces command, as illustrated in the following example:

  Router> show ip nat statistics | section interfaces
  Outside interfaces:
    GigabitEthernet0/0
  Inside interfaces: 
    GigabitEthernet0/1
  Router>

  Checking for an Active VRF Feature

  The second requirement for the vulnerable condition is for VRF to be active in at least one interface. In that case, the show ip vrf command, will include at least one line with an interface name as illustrated in the following example:

  
  

  Router> show ip vrf      
    Name                             Default RD          Interfaces
    Red-VRF                          1:1                 Gi0/1
  

  Determine the Cisco IOS Software Release

  To determine the Cisco IOS Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS Software by displaying text similar to "Cisco Internetwork Operating System Software" or "Cisco IOS Software." The image name displays in parentheses, followed by "Version" and the Cisco IOS Software release name. Other Cisco devices do not have the show version command or may provide different output.

  The following example identifies a Cisco product that is running Cisco IOS Software Release 15.0(1)M1 with an installed image name of C3900-UNIVERSALK9-M:

  Router> show version 
  Cisco IOS Software, C3900 Software (C3900-UNIVERSALK9-M), Version 15.0(1)M1, RELEASE SOFTWARE (fc1)
  Technical Support: http://www.cisco.com/techsupport
  Copyright (c) 1986-2009 by Cisco Systems, Inc.
  Compiled Wed 02-Dec-09 17:17 by prod_rel_team

  !--- output truncated 

  Additional information about Cisco IOS Software release naming conventions is available in "White Paper: Cisco IOS and NX-OS Software Reference Guide" at http://www.cisco.com/web/about/security/intelligence/ios-ref.html.

  Products Confirmed Not Vulnerable

  A Cisco IOS device is not vulnerable if the VRF-aware NAT feature is not configured.

  The following products have been confirmed not vulnerable:

  • Cisco IOS XE Software
  • Cisco IOS XR Software
  • Cisco NX-OS Software
  • Cisco ASA Sofware

  No other Cisco products are currently known to be affected by this vulnerability.

Details

• A vulnerability exists in the VRF-aware NAT implementation of Cisco IOS Software that could allow an unauthenticated, remote attacker to cause a memory starvation condition. The vulnerability issue is due to improper handling of a race condition that leads to a reduction in the available memory in the affected device. An attacker could repeatedly exploit this vulnerability, leading to a DoS condition. This vulnerability can be exploited using IP version 4 (IPv4) packets. A TCP three-way handshake is not required to exploit this vulnerability.

  This vulnerability has been documented in Cisco Bug ID CSCtg47129 (registered customers only) and CSCtz96745 (registered customers only) and has been assigned the Common Vulnerabilities and Exposures (CVE) ID CVE-2013-1142.

Workarounds

• There are no workarounds for this vulnerability.

Fixed Software

• When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Cisco IOS Software

  Each row of the following Cisco IOS Software table corresponds to a Cisco IOS Software train. If a particular train is vulnerable, the earliest releases that contain the fix are listed in the First Fixed Release column. The First Fixed Release for All Advisories in the March 2013 Bundled Publication column lists the earliest possible releases that correct all the published vulnerabilities in the Cisco IOS Software Security Advisory bundled publication. Cisco recommends upgrading to the latest available release where possible.

  The Cisco IOS Software Checker allows customers to search for Cisco Security Advisories that address specific Cisco IOS Software releases. This tool is available on the Cisco Security (SIO) portal at http://tools.cisco.com/security/center/selectIOSVersion.x

  Major Release	Availability of Repaired Releases
  Affected 12.0-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  There are no affected 12.0 based releases
  Affected 12.2-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  12.2	Not vulnerable	Not vulnerable
  12.2B	Not vulnerable	Not vulnerable
  12.2BC	Not vulnerable	Not vulnerable
  12.2BW	Not vulnerable	Not vulnerable
  12.2BX	Not vulnerable	Not vulnerable
  12.2BY	Not vulnerable	Not vulnerable
  12.2BZ	Not vulnerable	Not vulnerable
  12.2CX	Not vulnerable	Not vulnerable
  12.2CY	Not vulnerable	Not vulnerable
  12.2CZ	Not vulnerable	Not vulnerable
  12.2DA	Not vulnerable	Not vulnerable
  12.2DD	Not vulnerable	Not vulnerable
  12.2DX	Not vulnerable	Not vulnerable
  12.2EU	Not vulnerable	Not vulnerable
  12.2EW	Vulnerable; First fixed in Release 12.2SG Releases up to and including 12.2(20)EW4 are not vulnerable.	Vulnerable; First fixed in Release 12.2SG Releases up to and including 12.2(20)EW4 are not vulnerable.
  12.2EWA	Vulnerable; First fixed in Release 12.2SG Releases up to and including 12.2(20)EWA4 are not vulnerable.	Vulnerable; First fixed in Release 12.2SG Releases up to and including 12.2(20)EWA4 are not vulnerable.
  12.2EX	Vulnerable; First fixed in Release 15.0SE Releases up to and including 12.2(37)EX are not vulnerable.	Vulnerable; First fixed in Release 15.0SE Releases up to and including 12.2(37)EX are not vulnerable.
  12.2EY	Releases prior to 12.2(58)EY are vulnerable; Releases 12.2(58)EY and later are not vulnerable. First fixed in Release 15.1EY	Vulnerable; First fixed in Release 15.2S
  12.2EZ	Vulnerable; First fixed in Release 15.0SE	Vulnerable; First fixed in Release 15.0SE
  12.2FX	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2FY	Vulnerable; First fixed in Release 15.0SE	Vulnerable; First fixed in Release 15.0SE
  12.2FZ	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2IRA	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2IRB	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2IRC	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2IRD	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2IRE	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2IRF	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2IRG	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IRH	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IRI	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXA	Not vulnerable	Not vulnerable
  12.2IXB	Not vulnerable	Not vulnerable
  12.2IXC	Not vulnerable	Not vulnerable
  12.2IXD	Not vulnerable	Not vulnerable
  12.2IXE	Not vulnerable	Not vulnerable
  12.2IXF	Not vulnerable	Not vulnerable
  12.2IXG	Not vulnerable	Not vulnerable
  12.2IXH	Not vulnerable	Not vulnerable
  12.2JA	Not vulnerable	Not vulnerable
  12.2JK	Not vulnerable	Not vulnerable
  12.2MB	Not vulnerable	Not vulnerable
  12.2MC	Not vulnerable	Not vulnerable
  12.2MRA	Vulnerable; First fixed in Release 12.2SRE	Vulnerable; First fixed in Release 12.2SRE
  12.2MRB	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2S	Vulnerable. Only releases 12.2(25)S throughout 12.2(25)S15 are vulnerable.	Vulnerable. Only releases 12.2(25)S through 12.2(25)S15 are vulnerable
  12.2SB	12.2(33)SB12	12.2(33)SB12
  12.2SBC	Vulnerable; First fixed in Release 12.2SB	Vulnerable; First fixed in Release 12.2SB
  12.2SCA	Vulnerable; First fixed in Release 12.2SCF	Vulnerable; First fixed in Release 12.2SCF
  12.2SCB	Vulnerable; First fixed in Release 12.2SCF	Vulnerable; First fixed in Release 12.2SCF
  12.2SCC	Vulnerable; First fixed in Release 12.2SCF	Vulnerable; First fixed in Release 12.2SCF
  12.2SCD	Vulnerable; First fixed in Release 12.2SCF	Vulnerable; First fixed in Release 12.2SCF
  12.2SCE	Vulnerable; First fixed in Release 12.2SCF	Vulnerable; First fixed in Release 12.2SCF
  12.2SCF	12.2(33)SCF4	12.2(33)SCF4
  12.2SCG	Not vulnerable	Not vulnerable
  12.2SCH	Not vulnerable	Not vulnerable
  12.2SE	Not vulnerable	12.2(55)SE7 Releases up to and including 12.2(54)SE4 are not vulnerable.
  12.2SEA	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2SEB	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2SEC	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2SED	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2SEE	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2SEF	Vulnerable; First fixed in Release 12.2SE	Vulnerable; First fixed in Release 15.0SE
  12.2SEG	Releases prior to 12.2(25)SEG4 are vulnerable; Releases 12.2(25)SEG4 and later are not vulnerable. First fixed in Release 15.0SE	Releases prior to 12.2(25)SEG4 are vulnerable; Releases 12.2(25)SEG4 and later are not vulnerable. First fixed in Release 15.0SE
  12.2SG	12.2(53)SG8	12.2(53)SG9
  12.2SGA	Vulnerable; First fixed in Release 12.2SG	Vulnerable; First fixed in Release 12.2SG
  12.2SM	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SO	Not vulnerable	Not vulnerable
  12.2SQ	12.2(50)SQ5	12.2(50)SQ5
  12.2SRA	Vulnerable; First fixed in Release 12.2SRE ‡	Vulnerable; First fixed in Release 12.2SRE
  12.2SRB	Vulnerable; First fixed in Release 12.2SRE ‡	Vulnerable; First fixed in Release 12.2SRE
  12.2SRC	Vulnerable; First fixed in Release 12.2SRE ‡	Vulnerable; First fixed in Release 12.2SRE
  12.2SRD	Vulnerable; First fixed in Release 12.2SRE ‡	Vulnerable; First fixed in Release 12.2SRE
  12.2SRE	12.2(33)SRE6 ‡	12.2(33)SRE8
  12.2STE	Not vulnerable	Not vulnerable
  12.2SU	Not vulnerable	Not vulnerable
  12.2SV	Vulnerable. Only releases 12.2(25)SV2, 12.2(27)SV5 and 12.2(29)SV3 are vulnerable.	Vulnerable. Only releases 12.2(25)SV2, 12.2(27)SV5 and 12.2(29)SV3 are vulnerable.
  12.2SVA	Not vulnerable	Not vulnerable
  12.2SVC	Not vulnerable	Not vulnerable
  12.2SVD	Not vulnerable	Not vulnerable
  12.2SVE	Not vulnerable	Not vulnerable
  12.2SW	Vulnerable; First fixed in Release 12.4SW	Vulnerable; First fixed in Release 15.0M * Releases up to and including 12.2(23)SW1 are not vulnerable.
  12.2SX	Not vulnerable	Not vulnerable
  12.2SXA	Not vulnerable	Not vulnerable
  12.2SXB	Not vulnerable	Not vulnerable
  12.2SXD	Not vulnerable	Not vulnerable
  12.2SXE	Not vulnerable	Not vulnerable
  12.2SXF	Not vulnerable	Not vulnerable
  12.2SXH	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXI	12.2(33)SXI11	12.2(33)SXI11
  12.2SXJ	12.2(33)SXJ5	12.2(33)SXJ5
  12.2SY	12.2(50)SY4	12.2(50)SY4
  12.2SZ	Not vulnerable	Not vulnerable
  12.2T	Not vulnerable	Not vulnerable
  12.2TPC	Not vulnerable	Not vulnerable
  12.2WO	Not vulnerable	Not vulnerable
  12.2XA	Not vulnerable	Not vulnerable
  12.2XB	Not vulnerable	Not vulnerable
  12.2XC	Not vulnerable	Not vulnerable
  12.2XD	Not vulnerable	Not vulnerable
  12.2XE	Not vulnerable	Not vulnerable
  12.2XF	Not vulnerable	Not vulnerable
  12.2XG	Not vulnerable	Not vulnerable
  12.2XH	Not vulnerable	Not vulnerable
  12.2XI	Not vulnerable	Not vulnerable
  12.2XJ	Not vulnerable	Not vulnerable
  12.2XK	Not vulnerable	Not vulnerable
  12.2XL	Not vulnerable	Not vulnerable
  12.2XM	Not vulnerable	Not vulnerable
  12.2XNA	Please see Cisco IOS XE Software Availability	Please see Cisco IOS XE Software Availability
  12.2XNB	Please see Cisco IOS XE Software Availability	Please see Cisco IOS XE Software Availability
  12.2XNC	Please see Cisco IOS XE Software Availability	Please see Cisco IOS XE Software Availability
  12.2XND	Please see Cisco IOS XE Software Availability	Please see Cisco IOS XE Software Availability
  12.2XNE	Please see Cisco IOS XE Software Availability	Please see Cisco IOS XE Software Availability
  12.2XNF	Please see Cisco IOS XE Software Availability	Please see Cisco IOS XE Software Availability
  12.2XO	Releases prior to 12.2(54)XO are vulnerable; Releases 12.2(54)XO and later are not vulnerable. First fixed in Release 12.2SG	Releases prior to 12.2(54)XO are vulnerable; Releases 12.2(54)XO and later are not vulnerable. First fixed in Release 12.2SG
  12.2XQ	Not vulnerable	Not vulnerable
  12.2XR	Not vulnerable	Not vulnerable
  12.2XS	Not vulnerable	Not vulnerable
  12.2XT	Not vulnerable	Not vulnerable
  12.2XU	Not vulnerable	Not vulnerable
  12.2XV	Not vulnerable	Not vulnerable
  12.2XW	Not vulnerable	Not vulnerable
  12.2YA	Not vulnerable	Not vulnerable
  12.2YC	Not vulnerable	Not vulnerable
  12.2YD	Not vulnerable	Not vulnerable
  12.2YE	Not vulnerable	Not vulnerable
  12.2YK	Not vulnerable	Not vulnerable
  12.2YO	Not vulnerable	Not vulnerable
  12.2YP	Not vulnerable	Not vulnerable
  12.2YT	Not vulnerable	Not vulnerable
  12.2YW	Not vulnerable	Not vulnerable
  12.2YX	Not vulnerable	Not vulnerable
  12.2YY	Not vulnerable	Not vulnerable
  12.2YZ	Not vulnerable	Not vulnerable
  12.2ZA	Not vulnerable	Not vulnerable
  12.2ZB	Not vulnerable	Not vulnerable
  12.2ZC	Not vulnerable	Not vulnerable
  12.2ZD	Not vulnerable	Not vulnerable
  12.2ZE	Not vulnerable	Not vulnerable
  12.2ZH	Not vulnerable	Not vulnerable
  12.2ZJ	Not vulnerable	Not vulnerable
  12.2ZP	Not vulnerable	Not vulnerable
  12.2ZU	Not vulnerable	Not vulnerable
  12.2ZX	Not vulnerable	Not vulnerable
  12.2ZY	Not vulnerable	Not vulnerable
  12.2ZYA	Not vulnerable	Not vulnerable
  Affected 12.3-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  12.3	Not vulnerable	Not vulnerable
  12.3B	Not vulnerable	Not vulnerable
  12.3BC	Not vulnerable	Not vulnerable
  12.3BW	Not vulnerable	Not vulnerable
  12.3JA	Not vulnerable	Not vulnerable
  12.3JEA	Not vulnerable	Not vulnerable
  12.3JEB	Not vulnerable	Not vulnerable
  12.3JEC	Not vulnerable	Not vulnerable
  12.3JED	Not vulnerable	Not vulnerable
  12.3JEE	Not vulnerable	Not vulnerable
  12.3JK	Releases up to and including 12.3(2)JK3 are not vulnerable. Releases 12.3(8)JK1 and later are not vulnerable. First fixed in Release 12.4	Releases up to and including 12.3(2)JK3 are not vulnerable. Releases 12.3(8)JK1 and later are not vulnerable. First fixed in Release 15.0M *
  12.3JL	Not vulnerable	Not vulnerable
  12.3JX	Not vulnerable	Not vulnerable
  12.3T	Vulnerable; First fixed in Release 12.4 Releases up to and including 12.3(2)T9 are not vulnerable.	Vulnerable; First fixed in Release 15.0M * Releases up to and including 12.3(2)T9 are not vulnerable.
  12.3TPC	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.3XA	Not vulnerable	Not vulnerable
  12.3XB	Not vulnerable	Not vulnerable
  12.3XC	Not vulnerable	Not vulnerable
  12.3XD	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XE	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XF	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.3XG	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XI	Vulnerable; First fixed in Release 12.2SB	Vulnerable; First fixed in Release 12.2SB
  12.3XJ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3XK	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XL	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3XQ	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XR	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XU	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3XW	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3XX	Vulnerable; First fixed in Release 12.4	Vulnerable; First fixed in Release 15.0M *
  12.3XY	Not vulnerable	Not vulnerable
  12.3XZ	Not vulnerable	Not vulnerable
  12.3YD	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YF	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YG	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YI	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YJ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YK	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YM	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YQ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YS	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YT	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YU	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YX	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.3YZ	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.3ZA	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  Affected 12.4-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  12.4	12.4(25g)	Vulnerable; First fixed in Release 15.0M *
  12.4GC	12.4(24)GC5	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JA	Not vulnerable	Not vulnerable
  12.4JAL	Not vulnerable	Not vulnerable
  12.4JAM	Releases prior to 12.4(25e)JAM are vulnerable; Releases 12.4(25e)JAM and later are not vulnerable. Migrate to any release in 12.4JAN 12.4(25e)JAM	Releases prior to 12.4(25e)JAM are vulnerable; Releases 12.4(25e)JAM and later are not vulnerable. Migrate to any release in 12.4JAN12.4(25e)JAM
  12.4JAX	Not vulnerable	Not vulnerable
  12.4JAZ	Not vulnerable	Not vulnerable
  12.4JDA	Not vulnerable	Not vulnerable
  12.4JDC	Not vulnerable	Not vulnerable
  12.4JDD	Not vulnerable	Not vulnerable
  12.4JDE	Not vulnerable	Not vulnerable
  12.4JHA	Not vulnerable	Not vulnerable
  12.4JHB	Not vulnerable	Not vulnerable
  12.4JHC	Not vulnerable	Not vulnerable
  12.4JK	Not vulnerable	Not vulnerable
  12.4JL	Not vulnerable	Not vulnerable
  12.4JX	Not vulnerable	Not vulnerable
  12.4JY	Not vulnerable	Not vulnerable
  12.4JZ	Not vulnerable	Not vulnerable
  12.4MD	12.4(24)MD7	Vulnerable; First fixed in Release 12.4MDB
  12.4MDA	12.4(24)MDA11	Vulnerable; First fixed in Release 12.4MDB
  12.4MDB	12.4(24)MDB	12.4(24)MDB13
  12.4MR	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4MRA	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4MRB	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4SW	12.4(15)SW8a	Vulnerable; First fixed in Release 15.0M *
  12.4T	12.4(15)T17 12.4(24)T7	Vulnerable; First fixed in Release 15.0M *
  12.4XA	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XB	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XC	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XD	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XE	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XF	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XG	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XJ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XK	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XL	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XM	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XN	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XP	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XQ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XR	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XT	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XV	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XW	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XY	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4XZ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4YA	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M *
  12.4YB	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4YD	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4YE	12.4(24)YE7	12.4(24)YE3e
  12.4YG	12.4(24)YG4	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  Affected 15.0-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  15.0EB	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.0ED	Not vulnerable	Not vulnerable
  15.0EY	Not vulnerable	Not vulnerable
  15.0M	15.0(1)M4	15.0(1)M10 *
  15.0MR	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.0S	Vulnerable; First fixed in Release 15.1S ‡ Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	Vulnerable; First fixed in Release 15.1S Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.0SE	Not vulnerable	15.0(2)SE1
  15.0SG	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.0SQA	Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.0SY	15.0(1)SY4	15.0(1)SY4
  15.0XA	Vulnerable; First fixed in Release 15.1T	Vulnerable; First fixed in Release 15.1M
  15.0XO	Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  Affected 15.1-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  15.1EY	15.1(2)EY4	Vulnerable; First fixed in Release 15.2S
  15.1GC	15.1(2)GC2 15.1(4)GC	15.1(4)GC1
  15.1M	Not vulnerable	15.1(4)M6
  15.1MR	15.1(3)MR	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1MRA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1S	† See footnote Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	†See footnote Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.1SG	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.1SNG	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1SNH	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1SNI	Vulnerable; migrate to any release in 15.2SNG	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1SVA	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1SVC	Not vulnerable	Not vulnerable
  15.1SY	15.1(1)SY1; Available on 24-MAY-13	15.1(1)SY1; Available on 24-MAY-13
  15.1T	15.1(1)T4 15.1(2)T5 15.1(3)T	Vulnerable; First fixed in Release 15.1M
  15.1XB	Vulnerable; First fixed in Release 15.1T	Vulnerable; First fixed in Release 15.1M
  Affected 15.2-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  15.2GC	Not vulnerable	Vulnerable; migrate to any release in 15.4T
  15.2GCA	Not vulnerable	Vulnerable; migrate to any release in 15.4T
  15.2JA	Not vulnerable	15.2(2)JA
  15.2JAX	Not vulnerable	Not vulnerable
  15.2JB	Not vulnerable	Not vulnerable
  15.2JN	Not vulnerable	Not vulnerable
  15.2M	Not vulnerable	15.2(4)M3
  15.2S	15.2(2)S2 15.2(4)S1 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	15.2(4)S2 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.2SA	Not vulnerable	15.2(2)SA
  15.2SNG	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.2SNH	15.2(2)SNH1	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.2SNI	Not vulnerable	Not vulnerable
  15.2T	Not vulnerable	15.2(1)T4; Available on 03-MAY-13 15.2(2)T3 15.2(3)T3
  Affected 15.3-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2013 Bundled Publication
  There are no affected 15.3 based releases

  * Cisco IOS Software Release 15.0M will reach End of Software Maintenance on April 1, 2013, and no additional rebuilds will occur. Please review the End-of-Life Notice for additional information. Customers are advised to consider migrating to Cisco IOS Software Release 15.1M.

  † For Cisco 7600 Series Routers, the first fixed release for all Cisco Security Advisories in the March 2013 bundled publication is Cisco IOS Software Release 15.1(3)S5. For Cisco 7200 and 7300 Series Routers, the first fixed release for all advisories in the March 2013 bundled publication is Cisco IOS Software Release 15.1(3)S5a, which will be available on April 15, 2013.

  ‡ The VRF-aware NAT feature is not supported by any Cisco IOS Software release that runs on Cisco 7600 Series Routers. Note that this feature can be configured in some releases as documented in Cisco Bug ID CSCta48550( registered customers only) and CSCud19257( registered customers only)

  Cisco IOS XE Software

  Cisco IOS XE Software is not affected by the vulnerability that is disclosed in this document.

  Cisco IOS XR Software

  Cisco IOS XR is not affected.

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

  This vulnerability was found when troubleshooting a customer case.

URL

• http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130327-nat

Revision History

• Revision 1.3	2013-April-11	Updated 15.0SE train vulnerability status and added note on VRF-aware and Cisco 7600 Series Routers.
  Revision 1.2	2013-March-28	Updated "Software Versions and Fixes" section, corrected software table.
  Revision 1.1	2013-March-27	Update 12.4T in the Cisco IOS Software table.
  Revision 1.0	2013-March-27	Initial public release.

  Show Complete History...