30 July 2003
Source: http://www.cisco.com/warp/public/707/cisco-sa-20050729-ipv6.shtml

Quote below from this file:

This vulnerability was disclosed on July 27, 2005 at the Black Hat security conference.

Cisco Security Advisory: IPv6 Crafted Packet Vulnerability

Document ID: 65783

Revision 1.2

Last Updated 2005 July 30 1300 UTC

For Public Release 2005 July 29 0800 UTC

Please provide your feedback on this document.

Contents

Summary
Affected Products
Details
Impact
Software Versions and Fixes
Obtaining Fixed Software
Workarounds
Exploitation and Public Announcements
Status of This Notice: INTERIM
Distribution
Revision History
Cisco Security Procedures

Summary

Cisco Internetwork Operating System (IOS®) Software is vulnerable to a Denial of Service (DoS) and potentially an arbitrary code execution attack from a specifically crafted IPv6 packet. The packet must be sent from a local network segment. Only devices that have been explicitly configured to process IPv6 traffic are affected. Upon successful exploitation, the device may reload or be open to further exploitation.

Cisco has made free software available to address this vulnerability for all affected customers.

This advisory will be posted at http://www.cisco.com/warp/public/707/cisco-sa-20050729-ipv6.shtml.

Affected Products

Vulnerable Products

This issue affects all Cisco devices running any unfixed version of Cisco IOS or Cisco IOS XR code that supports, and is configured for, IPv6. A system which supports IPv6, if not specifically configured for IPv6, is not affected. You can use the show ipv6 interface command to determine whether IPv6 is enabled on a system.

Sample output of the show ipv6 interface command is shown below for two systems, one not configured for IPv6 and one configured for IPv6.

An empty output or an error message will be displayed if IPv6 is disabled or unsupported on the system. 

Router#show ipv6 int fa 0/0

-here you see blank output

In the example below the system is vulnerable. 

Router#show ipv6 interface
Serial1/0 is up, line protocol is up
  IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:D200
  Global unicast address(es):
    2001:1:33::3, subnet is 2001:1:33::/64 
  Joined group address(es):
    FF02::1
    FF02::1:FF00:3
    FF02::1:FF00:D200
  MTU is 1500 bytes
  ICMP error messages limited to one every 100 milliseconds
  ICMP redirects are enabled
  ND DAD is enabled, number of DAD attempts: 1
  ND reachable time is 30000 milliseconds
Router#

A router that has IPv6 enabled on a physical or logical interface is vulnerable to this issue even if ipv6 unicast-routing is globally disabled. The show ipv6 interface command can be used to determine whether IPv6 is enabled on any interface.

To determine the software running on a Cisco product, log in to the device and issue the show version command to display the system banner. Cisco IOS Software will identify itself as "Internetwork Operating System Software" or simply "IOS." On the next line of output, the image name will be displayed between parentheses, followed by "Version" and the IOS release name. Other Cisco devices will not have the show version command or will give different output.

The following example shows a product running IOS release 12.3(6) with an image name of C2600-JS-MZ: 

Cisco Internetwork Operating System Software IOS (tm)

C2600 Software (C2600-JS-MZ), Version 12.3(6), RELEASE SOFTWARE (fc1)

Additional information about Cisco IOS release naming can be found at http://www.cisco.com/warp/public/620/1.html.

A system that is running a Cisco IOS XR version prior to 3.2 is also affected by this vulnerability if configured for IPv6. The show ipv6 interface command can be used to identify whether IPv6 is enabled on a system running Cisco IOS XR.

Products Confirmed Not Vulnerable

Products that are not running Cisco IOS or Cisco IOS XR are not affected.

Products running any version of Cisco IOS that do not have IPv6 configured interfaces are not vulnerable.

No other Cisco products are currently known to be affected by these vulnerabilities.

Details

IPv6 is the "Internet Protocol Version 6", designed by the Internet Engineering Task Force (IETF) to replace the current version Internet Protocol, IP Version 4 (IPv4).

A vulnerability exists in the processing of IPv6 packets. Crafted packets from the local segment received on logical interfaces (that is, tunnels including 6to4 tunnels) as well as physical interfaces can trigger this vulnerability. Crafted packets can not traverse a 6to4 tunnel and attack a box across the tunnel.

The crafted packet must be sent from a local network segment to trigger the attack. This vulnerability can not be exploited one or more hops from the IOS device.

This issue is documented in Cisco bug ID CSCef68324 ( registered customers only) for Cisco IOS, and CSCeh74956 ( registered customers only) for Cisco IOS XR.

Impact

Successful exploitation of the vulnerability on Cisco IOS may result in a reload of the device or execution of arbitrary code. Repeated exploitation could result in a sustained DoS attack or execution of arbitrary code on Cisco IOS devices.

Successful exploitation of the vulnerability on Cisco IOS-XR may result in a restart of the IPv6 neighbor discovery process. A restart of this process will only affect IPv6 traffic passing through the system. All other processes and traffic will be unaffected. Repeated exploitation could result in a sustained DoS attack on IPv6 traffic.

Software Versions and Fixes

Each row of the Cisco IOS software table below describes a release train and the platforms or products for which it is intended. If a given release train is vulnerable, then the earliest possible releases that contain the fix (the First Fixed Release) and the anticipated date of availability for each are listed in the Rebuild and Maintenance columns. A device running a release in the given train that is earlier than the release in a specific column (less than the First Fixed Release) is known to be vulnerable. The release should be upgraded at least to the indicated release or a later version (greater than or equal to the First Fixed Release label).

Major Release Availability of Repaired Releases
Affected 12.0-Based Release Rebuild Maintenance
12.0S 12.0(26)S6  
  12.0(27)S5  
  12.0(28)S3  
  12.0(30)S2 12.0(31)S
12.0SX Vulnerable; contact TAC
12.0SL Vulnerable; migrate to 12.0(31)S or later
12.0ST Vulnerable; migrate to 12.0(31)S or later
12.0SY Vulnerable; migrate to 12.0(31)S or later
Affected 12.1-Based Release Rebuild Maintenance
12.1XU Vulnerable; migrate to 12.3(15) or later
12.1XV Vulnerable; migrate to 12.3(15) or later
12.1YB Vulnerable; migrate to 12.3(15) or later
12.1YC Vulnerable; migrate to 12.3(15) or later
12.1YD Vulnerable; migrate to 12.3(15) or later
12.1YE Vulnerable; migrate to 12.3(15) or later
12.1YF Vulnerable; migrate to 12.3(15) or later
12.1YH Vulnerable; migrate to 12.3(15) or later
12.1YI Vulnerable; migrate to 12.3(15) or later
Affected 12.2-Based Release Rebuild Maintenance
12.2B Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2BC Vulnerable; contact TAC
12.2BW Vulnerable; migrate to 12.3(15) or later
12.2BY Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2BX Vulnerable; migrate to 12.3(7)XI4 or later
12.2BZ Vulnerable; migrate to 12.3(7)XI4 or later
12.2CX Vulnerable; contact TAC
12.2CY Vulnerable; contact TAC
12.2CZ Vulnerable; contact TAC
12.2DD Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2DX Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2EU 12.2(20)EU1  
12.2EW Vulnerable; migrate to 12.2(25)EWA
12.2EWA 12.2(25)EWA1  
12.2EX Vulnerable; migrate to 12.2(25)SEA or later
12.2EY Not vulnerable
12.2EZ   12.2(25)EZ
12.2JA Vulnerable; migrate to 12.3(4)JA or later
12.2JK Vulnerable; contact TAC
12.2MB Vulnerable; contact TAC
12.2MC Vulnerable; migrate to 12.4(2)MR
12.2MX Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2S 12.2(14)S14  
12.2(18)S9  
12.2(20)S8  
12.2(25)S4  
12.2SE Vulnerable; migrate to 12.2(25)SEB or later
12.2SEA Not vulnerable
12.2SEB Not vulnerable
12.2SEC Not vulnerable
12.2SO Vulnerable; contact TAC
12.2SU Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2SV 12.2(23)SV1 12.2(26)SV
12.2SW Vulnerable; contact TAC
12.2SX Vulnerable; migrate to 12.2(17d)SXB8 or later
12.2SXA Vulnerable; migrate to 12.2(17d)SXB8 or later
12.2SXB 12.2(17d)SXB8  
12.2SXD 12.2(18)SXD4  
12.2SXE 12.2(18)SXE1  
12.2SY Vulnerable; migrate to 12.2(17d)SXB8 or later
12.2SZ Vulnerable; migrate to 12.2(20)S8 or later
12.2T 12.2(13)T16  
12.2(15)T16  
12.2XA Vulnerable; migrate to 12.3(15) or later
12.2XB Vulnerable; migrate to 12.3(15) or later
12.2XC Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2XD Vulnerable; migrate to 12.3(15) or later
12.2XE Vulnerable; migrate to 12.3(15) or later
12.2XF Vulnerable; contact TAC
12.2XG Vulnerable; migrate to 12.3(15) or later
12.2XH Vulnerable; migrate to 12.3(15) or later
12.2XI Vulnerable; migrate to 12.3(15) or later
12.2XJ Vulnerable; migrate to 12.3(15) or later
12.2XK Vulnerable; migrate to 12.3(15) or later
12.2XL Vulnerable; migrate to 12.3(15) or later
12.2XM Vulnerable; migrate to 12.3(15) or later
12.2XN Vulnerable; migrate to 12.3(15) or later
12.2XQ Vulnerable; migrate to 12.3(15) or later
12.2XR Vulnerable; migrate to 12.3(4)JA or later
12.2XT Vulnerable; migrate to 12.3(15) or later
12.2XU Vulnerable; migrate to 12.3(15) or later
12.2XW Vulnerable; migrate to 12.3(15) or later
12.2XZ Vulnerable; migrate to 12.3(15) or later
12.2YA 12.2(4)YA10
12.2YB Vulnerable; migrate to 12.3(15) or later
12.2YC Vulnerable; migrate to 12.3(15) or later
12.2YD Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YE Vulnerable; migrate to 12.2(25)S4 or later
12.2YF Vulnerable; migrate to 12.3(15) or later
12.2YG Vulnerable; migrate to 12.3(15) or later
12.2YH Vulnerable; migrate to 12.3(15) or later
12.2YJ Vulnerable; migrate to 12.3(15) or later
12.2YK Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YL Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YM Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YN Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YO Vulnerable; migrate to 12.2(17d)SXB8 or later
12.2YP Vulnerable; migrate to 12.3(15) or later
12.2YQ Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YR Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YT Vulnerable; migrate to 12.2(15)T16 or later
12.2YU Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YV Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YW Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YX Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YY Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2YZ Vulnerable; migrate to 12.2(20)S8 or later
12.2ZA Vulnerable; migrate to 12.2(17d)SXB8 or later
12.2ZB Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2ZC Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2ZD Vulnerable; contact TAC
12.2ZE Vulnerable; migrate to 12.3(15) or later
12.2ZF Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2ZG Vulnerable; contact TAC
12.2ZH Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2ZJ Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2ZL Vulnerable; contact TAC
12.2ZN Vulnerable; migrate to fixed 12.3(14)T2 or later
12.2ZO Vulnerable; migrate to 12.2(15)T16 or later
12.2ZP Vulnerable; contact TAC
Affected 12.3-Based Release Rebuild Maintenance
12.3 12.3(3h)  
12.3(5e)  
12.3(6e)  
12.3(9d)  
12.3(10d)  
12.3(12b)  
12.3(13a) 12.3(15)
12.3B 12.3(5a)B5  
12.3BC   12.3(13a)BC
12.3BW Vulnerable; migrate to fixed 12.3(14)T2 or later
12.3JA   12.3(4)JA
12.3JK   12.3(2)JK
12.3T 12.3(7)T9  
12.3(8)T8  
12.3(11)T5  
12.3(14)T2  
12.3XA Vulnerable; contact TAC
12.3XB Vulnerable; migrate to fixed 12.3(14)T2 or later
12.3XC 12.3(2)XC3  
12.3XD Vulnerable; contact TAC
12.3XE Vulnerable; contact TAC
12.3XF Vulnerable; migrate to fixed 12.3(14)T2 or later
12.3XG Vulnerable; contact TAC
12.3XH Vulnerable; migrate to fixed 12.3(14)T2 or later
12.3XI 12.3(7)XI4  
12.3XJ Vulnerable; migrate to 12.3(11)YF3 or later
12.3XK Vulnerable; contact TAC
12.3XL Vulnerable; contact TAC
12.3XM Vulnerable; migrate to fixed 12.3(14)T2 or later
12.3XQ 12.3(4)XQ1  
12.3XR 12.3(7)XR4  
12.3XS Vulnerable; migrate to 12.4(1) or later
12.3XT Vulnerable; contact TAC
12.3XU Vulnerable; migrate to 12.4(2)T or later
12.3XW Vulnerable; migrate to 12.3(11)YF3 or later
12.3XX Vulnerable; migrate to 12.4(1) or later
12.3XY Vulnerable; migrate to fixed 12.3(14)T2 or later
12.3YA 12.3(8)YA1  
12.3YD Vulnerable; contact TAC
12.3YF 12.3(11)YF3  
12.3YG 12.3(8)YG2  
12.3YH Vulnerable; migrate to 12.3(8)YI1 or later
12.3YI 12.3(8)YI1  
12.3YJ 12.3(11)YJ  
12.3YK Vulnerable; contact TAC
12.3YQ 12.3(14)YQ1  
12.3YS   12.3(11)YS
12.3YT   12.3(14)YT
12.3YU   12.3(14)YU
Affected 12.4-Based Release Rebuild Maintenance
12.4   12.4(1)
12.4MR   12.4(2)MR
12.4T   12.4(2)T

Product First Fixed Release
Cisco IOS XR IOS XR 3.2

A SMU for IOS XR 3.0.1 will be available on 2005-Aug-04.

A SMU for IOS XR 3.1.0 will be available on 2005-Aug-04.

For further information on the terms "Rebuild" and "Maintenance, " please consult the following URL: http://www.cisco.com/warp/public/620/1.html

When considering software upgrades, please also consult http://www.cisco.com/en/US/products/products_security_advisories_listing.html and any subsequent advisories to determine exposure and a complete upgrade solution.

In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center ("TAC") for assistance.

Obtaining Fixed Software

Customers with Service Contracts

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, this means that upgrades should be obtained through the Software Center on Cisco's worldwide website at http://www.cisco.com.

Customers using Third-party Support Organizations

Customers whose Cisco products are provided or maintained through prior or existing agreement with third-party support organizations such as Cisco Partners, authorized resellers, or service providers should contact that support organization for assistance with the upgrade, which should be free of charge.

Customers without Service Contracts

Customers who purchase direct from Cisco but who do not hold a Cisco service contract and customers who purchase through third-party vendors but are unsuccessful at obtaining fixed software through their point of sale should get their upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows.

Please have your product serial number available and give the URL of this notice as evidence of your entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC.

Please do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades.

See http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for additional TAC contact information, including special localized telephone numbers and instructions and e-mail addresses for use in various languages.

Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at http://www.cisco.com/public/sw-license-agreement.html, or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Workarounds

The effectiveness of any workaround is dependent on specific customer situations such as product mix, network topology, traffic behavior, and organizational mission. Due to the variety of affected products and releases, customers should consult with their service provider or support organization to ensure any applied workaround is the most appropriate for use in the intended network before it is deployed.

In networks where IPv6 is not needed but enabled, disabling IPv6 processing on an IOS device will eliminate exposure to this vulnerability. On a router which is configured for IPv6, this must be done by issuing the command no ipv6 enable and no ipv6 address on each interface.

Exploitation and Public Announcements

This vulnerability was disclosed on July 27, 2005 at the Black Hat security conference.

Status of This Notice: INTERIM

THIS ADVISORY IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE ADVISORY OR MATERIALS LINKED FROM THE ADVISORY IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS NOTICE AT ANY TIME. CISCO EXPECTS TO UPDATE THIS NOTICE WITHIN SIX WEEKS FROM THE ORIGINAL DATE OF THIS NOTICE.

>

A stand-alone copy or paraphrase of the text of this security advisory that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors.

Distribution

This advisory will be posted on Cisco's worldwide website at http://www.cisco.com/warp/public/707/cisco-sa-20050729-ipv6.shtml.

In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail and Usenet news recipients.

Future updates of this advisory, if any, will be placed on Cisco's worldwide website, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the above URL for any updates.

Revision History

Revision 1.2 2005-July-30 IOS XR added to Affected Products. Wording changes made in the Workarounds section. Fixed software table updated.
Revision 1.1 2005-July-29 Software Versions and Fixes table updated. First paragraph in the Vulnerable Products section updated.
Revision 1.0 2005-July-29 Initial public release.

Cisco Security Procedures

Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html. This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt.