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Cisco IOS Software Network Address Translation Vulnerability

Advisory ID: cisco-sa-20130327-nat

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

Revision 1.3

Last Updated  2013 April 11 17:17  UTC (GMT)

For Public Release 2013 March 27 16:00  UTC (GMT)


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 free 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.

Vulnerability Scoring Details

Cisco has scored the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this security advisory is in accordance with CVSS version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability severity and helps organizations determine the urgency and priority of a response.

Cisco has provided a base and temporal score. Customers can also compute environmental scores that help determine the impact of the vulnerability in their own networks.

Cisco has provided additional information regarding CVSS at the following link:

http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to compute the environmental impact for individual networks at the following link:

http://intellishield.cisco.com/security/alertmanager/cvss



CSCtg47129 and CSCtz96745

Calculate the environmental score of CSCtg47129 and CSCtz96745 Cisco IOS Software VRF Aware NAT Memory Starvation Vulnerability

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.1

Exploitability

Remediation Level

Report Confidence

Proof-of-Concept

Official-Fix

Confirmed


Impact

Successful exploitation of the vulnerability may cause the available memory to be reduced in the affected device. Continued exploitation will result in a sustained denial of service attack, this could lead to the device becoming non-responsive and cause a reload. A sustained peak CPU utilization can be a symptom of this condition and could make the device non-operational.

Software Versions and Fixes

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 Intelligence Operations (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.

Workarounds

There are no workarounds for this vulnerability.

Obtaining Fixed Software

Cisco has released free software updates that address the vulnerability described in this advisory. Prior to deploying software, customers are advised to consult their maintenance providers or check the software for feature set compatibility and known issues that are specific to their environments.

Customers may only install and expect support for feature sets they have purchased. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html.

Customers with Service Contracts

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, upgrades should be obtained through the Software Navigator on Cisco.com at http://www.cisco.com/cisco/software/navigator.html.

Customers using Third Party Support Organizations

Customers with Cisco products that are provided or maintained through prior or existing agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers, should contact that organization for assistance with the appropriate course of action.

The effectiveness of any workaround or fix depends on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Because of the variety of affected products and releases, customers should consult their service providers or support organizations to ensure that any applied workaround or fix is the most appropriate in the intended network before it is deployed.

Customers without Service Contracts

Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco Technical Assistance Center (TAC):

  • +1 800 553 2447 (toll free from within North America)
  • +1 408 526 7209 (toll call from anywhere in the world)
  • e-mail: tac@cisco.com

Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade. Customers without service contracts should request free upgrades through the TAC.

Refer to Cisco Worldwide Contacts at http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, instructions, and e-mail addresses for support in various languages.

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.

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 Security Intelligence Operations at the following link:

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

Additionally, a text version of this advisory is clear signed with the Cisco PSIRT PGP key and circulated among the following e-mail addresses:

  • cust-security-announce@cisco.com
  • first-bulletins@lists.first.org
  • bugtraq@securityfocus.com
  • vulnwatch@vulnwatch.org
  • cisco@spot.colorado.edu
  • cisco-nsp@puck.nether.net

Future updates of this advisory, if any, will reside on Cisco.com but may not be announced on mailing lists. Users can monitor this advisory's URL for any updates.


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.

Cisco Security Procedures

Complete information about reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco is available on Cisco.com at http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html. This web page includes instructions for press inquiries regarding Cisco Security Advisories. All Cisco Security Advisories are available at http://www.cisco.com/go/psirt.