Cisco Security Advisory

Cisco IOS Software DHCP Version 6 Server Denial of Service Vulnerability

Advisory ID: cisco-sa-20120926-dhcpv6

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120926-dhcpv6

Revision 1.1

Last Updated  2012 October 18 19:01  UTC (GMT)

For Public Release 2012 September 26 16:00  UTC (GMT)


Summary

Cisco IOS Software and Cisco IOS XE Software contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. An attacker could exploit this vulnerability by sending a crafted request to an affected device that has the DHCP version 6 (DHCPv6) server feature enabled, causing a reload.

Cisco has released free software updates that address this vulnerability.  This advisory is available at the following link:
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120926-dhcpv6

Note: The September 26, 2012, Cisco IOS Software Security Advisory bundled publication includes nine Cisco Security Advisories. Eight of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. 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 September 2012 bundled publication. 

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

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep12.html


Affected Products


Vulnerable Products

Cisco devices that are running affected Cisco IOS Software or Cisco IOS XE Software with the DHCPv6 server feature enabled are vulnerable. The DHCPv6 server feature is not enabled by default.  Cisco devices that are configured as DHCPv6 clients or relay agents are not affected by this vulnerability.    

To determine whether a Cisco IOS device or Cisco IOS XE device is configured as a DHCPv6 server, issue the show ipv6 dhcp interface command.  

The following example shows a Cisco IOS device that is not vulnerable because it is not configured as a DHCPv6 server:
Router#show ipv6 dhcp interface 
Router#
The following example shows a Cisco IOS device that is affected by this vulnerability. The device is vulnerable because the DHCPv6 server feature is applied to the FastEthernet0/0 interface:
Router#show ipv6 dhcp interface
FastEthernet0/0 is in server mode
  Using pool: DHCPv6-stateful
  Preference value: 0
  Hint from client: ignored
  Rapid-Commit: disabled
Router#

The following example shows a Cisco IOS device that is affected by this vulnerability. The device is vulnerable because the DHCPv6 server feature is applied to the FastEthernet0/0 and FastEthernet0/1 interfaces:
Router#show ipv6 dhcp interface | include server
FastEthernet0/0 is in server mode
FastEthernet0/1 is in server mode
Router#

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

Cisco IOS XR Software is not affected by this vulnerability.

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

Details

The DHCPv6 Server feature in Cisco IOS Software and Cisco IOS XE Software is a DHCPv6 server implementation that assigns and manages IPv6 addresses, prefixes and other information from specified address pools to DHCPv6 clients.

Cisco IOS Software and Cisco IOS XE Software contain a vulnerability that could allow an unauthenticated, remote attacker to cause a DoS condition. An attacker could exploit this vulnerability by sending a crafted request to an affected device that has the DHCPv6 server feature enabled, causing a reload.

The vulnerability is triggered when the affected Cisco IOS device attempts to process a malformed DHCPv6 packet. Valid DHCPv6 packets will not trigger this vulnerability. DHCPv6 packets that the Cisco IOS device forwards (for example, transit DHCPv6 traffic) will not trigger this vulnerability.  

Cisco IOS devices that are configured as a DHCP server for IPv4 are not affected by this vulnerability.

This vulnerability has been documented in Cisco bug ID CSCto57723 (registered customers only).  This vulnerability has been assigned the Common Vulnerabilities and Exposures (CVE) ID CVE-2012-4623.


Vulnerability Scoring Details

Cisco has scored the vulnerability 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




CSCto57723 - DHCPv6 Server Denial of Service Vulnerability

Calculate the environmental score of CSCto57723

CVSS Base Score - 7.1

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Medium

None

None

None

Complete

CVSS Temporal Score - 5.9

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed


Impact

Successful exploitation of the vulnerability may cause an affected device to reload.  Repeated exploitation could result in a sustained DoS condition.


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 September 2012 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 September 2012 Cisco IOS Software Security Advisory 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 September 2012 Cisco IOS Software Security Advisory Bundled Publication
12.2 Not vulnerable
Not vulnerable
12.2B Not vulnerable
Vulnerable; First fixed in Release 12.4
Releases up to and including 12.2(4)B8 are not vulnerable.
12.2BC Not vulnerable
Not vulnerable
12.2BW Not vulnerable
Not vulnerable
12.2BX Not vulnerable
12.2(15)BX
Releases up to and including 12.2(2)BX1 are 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
Vulnerable; migrate to any release in 12.2S
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 Not vulnerable
Not vulnerable
12.2EWA Not vulnerable
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 Vulnerable; First fixed in Release 15.1EY
Releases up to and including 12.2(46)EY are not vulnerable.
Vulnerable; First fixed in Release 15.1EY
Releases up to and including 12.2(46)EY are not vulnerable.
12.2EZ Not vulnerable
Not vulnerable
12.2FX Not vulnerable
Not vulnerable
12.2FY Not vulnerable
Not vulnerable
12.2FZ Not vulnerable
Not vulnerable
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
Releases up to and including 12.2(15)MC1 are not vulnerable. Releases 12.2(15)MC2b and later are not vulnerable. First fixed in Release 12.4
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 Not vulnerable
Not vulnerable
12.2SB 12.2(33)SB13
12.2(33)SB13
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
12.2SE 12.2(46)SE1
12.2(55)SE6
12.2(46)SE1
12.2(55)SE6
12.2SEA Not vulnerable
Not vulnerable
12.2SEB Not vulnerable
Not vulnerable
12.2SEC Not vulnerable
Not vulnerable
12.2SED Not vulnerable
Not vulnerable
12.2SEE Not vulnerable
Not vulnerable
12.2SEF Not vulnerable
Not vulnerable
12.2SEG Not vulnerable
Not vulnerable
12.2SG 12.2(53)SG8
12.2(53)SG8
Vulnerable; releases up to and including 12.2(46)SG1 are not vulnerable.
12.2SGA Not vulnerable
Not vulnerable
12.2SM Not vulnerable
Not vulnerable
12.2SO Not vulnerable
Not vulnerable
12.2SQ Releases up to and including 12.2(44)SQ2 are not vulnerable.
Releases up to and including 12.2(44)SQ2 are not vulnerable.
12.2SRA Not vulnerable
Not vulnerable
12.2SRB Not vulnerable
Not vulnerable
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)SRE7
12.2(33)SRE7
12.2STE Not vulnerable
Not vulnerable
12.2SU Not vulnerable
Not vulnerable
12.2SV Not vulnerable
Not 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 Not vulnerable
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 Not vulnerable

Vulnerable; releases up to and including 12.2(33)SXH7 are not vulnerable
12.2SXI 12.2(33)SXI10
12.2(33)SXI10
12.2SXJ 12.2(33)SXJ4
12.2(33)SXJ4
12.2SY 12.2(50)SY3
Only releases 12.2(50)SY through 12.2(50)SY2 are vulnerable.
12.2(50)SY3
12.2SZ Not vulnerable
Not vulnerable
12.2T Not vulnerable
Vulnerable; First fixed in Release 12.4
Releases up to and including 12.2(8)T10 are not vulnerable.
12.2TPC Not vulnerable
Not vulnerable
12.2WO Vulnerable; First fixed in Release 15.0SG
Vulnerable; First fixed in Release 15.0SG
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 Vulnerable; First fixed in Release 12.2SG
Releases up to and including 12.2(40)XO are not vulnerable.
Vulnerable; First fixed in Release 12.2SG
Releases up to and including 12.2(40)XO are not vulnerable.
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
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
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
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
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
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZE Not vulnerable
Vulnerable; First fixed in Release 12.4
12.2ZH Not vulnerable
Vulnerable; First fixed in Release 12.4
12.2ZJ Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZP Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZU Not vulnerable
Not vulnerable
12.2ZX Vulnerable; First fixed in Release 12.2SB
Vulnerable; First fixed in Release 12.2SB
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 September 2012 Cisco IOS Software Security Advisory Bundled Publication
12.3 Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3B Not vulnerable
Vulnerable; First fixed in Release 12.4
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 12.4
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(8)T11 are not vulnerable.
Vulnerable; First fixed in Release 12.4
12.3TPC Not vulnerable
Releases up to and including 12.3(4)TPC11a are not vulnerable.
12.3VA Not vulnerable
Not vulnerable
12.3XA Not vulnerable
Releases prior to 12.3(2)XA7 are vulnerable; Releases 12.3(2)XA7 and later are not vulnerable. First fixed in Release 12.4
12.3XB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.3XC Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XD Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XE Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XF Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.3XG Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XI Not vulnerable
12.3(7)XI1b
12.3XJ Not vulnerable
Vulnerable; First fixed in Release 12.4T
12.3XK Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XL Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3XQ Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XR Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XU Not vulnerable
Vulnerable; First fixed in Release 12.4T
Releases up to and including 12.3(8)XU1 are not vulnerable.
12.3XW Not vulnerable
Vulnerable; First fixed in Release 12.4T
12.3XX Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XY Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3XZ Not vulnerable
Vulnerable; First fixed in Release 12.4
12.3YD Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YF Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YG Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YI Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YJ Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YK Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YM Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YQ Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YS Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YT Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YU Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.3YX Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
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 Not vulnerable
Vulnerable; First fixed in Release 12.4T
Affected 12.4-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication
12.4 12.4(25g)
12.4(25g)
12.4GC 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.
12.4JA Not vulnerable
Not vulnerable
12.4JAL Not vulnerable
Not vulnerable
12.4JAX Not vulnerable
Not vulnerable
12.4JAY 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 Not vulnerable
12.4(24)MD7
12.4MDA Vulnerable; migrate to any release in 12.4MD
Releases up to and including 12.4(22)MDA6 are not vulnerable.

Releases up to and including 12.4(22)MDA6 are not vulnerable
12.4MDB 12.4(24)MDB10
12.4(24)MDB10
12.4MR Releases up to and including 12.4(16)MR are not vulnerable.
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 12.4T
12.4SW Not vulnerable
Not vulnerable
12.4T 12.4(24)T8
12.4(24)T8
12.4XA Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XB Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XC Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XD Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XE Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XF Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XG Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XJ Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XK Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
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 Releases up to and including 12.4(15)XM are not vulnerable.
Releases 12.4(15)XM3 and later are not vulnerable. First fixed in Release 12.4T
Releases up to and including 12.4(15)XM are not vulnerable. Releases 12.4(15)XM3 and later are not vulnerable. First fixed in Release 12.4T
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 12.4T
12.4XR Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XT Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
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 12.4T
12.4XY Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4XZ Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4YA Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
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 Vulnerable; First fixed in Release 12.4T
Vulnerable; First fixed in Release 12.4T
12.4YG Not vulnerable
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 September 2012 Cisco IOS Software Security Advisory Bundled Publication
15.0EX Not vulnerable
Not vulnerable
15.0EY Not vulnerable
Not vulnerable
15.0M 15.0(1)M9
15.0(1)M9
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.
15.0MRA 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 15.0(1)S6

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0(1)S6

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SE 15.0(2)SE


15.0(2)SE
15.0SG 15.0(2)SG5
15.0(2)SG6; Available on 11-OCT-12

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0(2)SG5
15.0(2)SG6 ; Available on 11-OCT-12

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SY 15.0(1)SY2
15.0(1)SY2
15.0XA Vulnerable; First fixed in Release 15.1M
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 September 2012 Cisco IOS Software Security Advisory Bundled Publication
15.1EY 15.1(2)EY4
15.1(2)EY4
15.1GC Vulnerable; First fixed in Release 15.1M
Vulnerable; First fixed in Release 15.1M
15.1M 15.1(4)M5
15.1(4)M5
15.1MR 15.1(3)MR; Available on 01-OCT-12
15.1(3)MR; Available on 01-OCT-12
15.1S
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability

15.1(3)S
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1SG 15.1(1)SG1

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1(1)SG1

15.1(2)SG 12-NOV-12
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; migrate to any release in 15.2SNG
15.1SV Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.1T Vulnerable; First fixed in Release 15.1M
Vulnerable; First fixed in Release 15.1M
15.1XB Vulnerable; First fixed in Release 15.1M
Vulnerable; First fixed in Release 15.1M
Affected 15.2-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication
15.2GC Releases prior to 15.2(3)GC are vulnerable; Releases 15.2(3)GC and later are not vulnerable. First fixed in Release 15.2T
Releases prior to 15.2(3)GC are vulnerable; Releases 15.2(3)GC and later are not vulnerable. First fixed in Release 15.2T
15.2JA Not vulnerable
Not Vulnerable
15.2M 15.2(4)M

Not vulnerable
15.2S Not vulnerable

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.2(1)S2
15.2(2)S1
15.2(4)S

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.2SNG Not vulnerable
Not vulnerable
15.2T 15.2(1)T3
15.2(2)T2
15.2(3)T2; Available on 12-OCT-12
15.2(1)T3
15.2(2)T2
15.2(3)T2; Available on 12-OCT-12

Cisco IOS XE Software

Cisco IOS XE Software is affected by this vulnerability.

Cisco IOS XE Software Release First Fixed Release First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication
2.1.x Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
2.2.x Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
2.3.x Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
2.4.x Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
2.5.x Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
2.6.x Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
3.1.xS 3.1.4S 3.1.4S
3.1.xSG Vulnerable; migrate to 3.2.5SG or later. Vulnerable; migrate to 3.2.5SG or later.
3.2.xS Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
3.2.xSG 3.2.5SG 3.2.5SG
3.2.xXO Vulnerable; migrate to 3.3.1SG or later Vulnerable; migrate to 3.3.1SG or later.
3.3.xS Vulnerable; migrate to 3.4.0S or later. Vulnerable; migrate to 3.6.0S or later.
3.3.x.SG 3.3.1SG 3.3.1SG
3.4.xS Not vulnerable Vulnerable; migrate to 3.6.0S or later.
3.5.xS Not vulnerable Vulnerable; migrate to 3.6.0S or later.
3.6.xS Not vulnerable Not vulnerable
3.7.xS Not vulnerable Not vulnerable

Cisco IOS XR Software

Cisco IOS XR Software is not affected by this vulnerability.

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 discovered by Cisco during internal testing.


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-20120926-dhcpv6

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
  • full-disclosure@lists.grok.org.uk

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 1.1 2012-October-18 Added Cisco IOS 12.2(46)SE1 as an additional First Fixed Release.
Revision 1.0 2012-September-26 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.


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