Cisco Security Advisory

Cisco IOS Software IP Version 6 over Multiprotocol Label Switching Vulnerabilities

Advisory ID: cisco-sa-20110928-ipv6mpls

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-ipv6mpls

Revision 1.2

Last Updated  2012 September 21 19:20  UTC (GMT)

For Public Release 2011 September 28 16:00  UTC (GMT)


Summary

Cisco IOS Software is affected by two vulnerabilities that cause a Cisco IOS device to reload when processing IP version 6 (IPv6) packets over a Multiprotocol Label Switching (MPLS) domain. These vulnerabilities are:

  • Crafted IPv6 Packet May Cause MPLS-Configured Device to Reload
  • ICMPv6 Packet May Cause MPLS-Configured Device to Reload

Cisco has released free software updates that address these vulnerabilities.

Workarounds that mitigate these vulnerabilities are available.

This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-ipv6mpls.

Note: The September 28, 2011, Cisco IOS Software Security Advisory bundled publication includes ten Cisco Security Advisories. Nine of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each 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 vulnerabilities in the September 2011 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_sep11.html

Affected Products

Vulnerable Products

Cisco IOS Software or Cisco IOS XE Software devices (hereafter both referenced as Cisco IOS Software in this document) that are running vulnerable versions of Cisco IOS Software and configured for MPLS are affected by two vulnerabilities related to IPv6 traffic that traverses an MPLS domain. The two vulnerabilities are independent of each other.

Note: IPv6 does not need to be configured on the affected devices themselves. The vulnerabilities do require the MPLS label switched packets to have specific IPv6 payloads to be exploited.

To determine whether a device is configured for MPLS, log in to the device and issue the command-line interface (CLI) command show mpls interface. If the IP state is Yes, the device is vulnerable. The following example shows a device that has MPLS configured on interface Ethernet0/0:

Router#show mpls interface
Interface       IP           Tunnel  BGP  Static  Operational 
Ethernet0/0   Yes (ldp)    No      No   No       Yes
Router#

The following two examples show responses from a device with MPLS forwarding disabled. The first example shows a return of no interfaces:

router#show mpls interface
Interface              IP            Tunnel   BGP Static Operational
routers#

In the second example, the device provides a message indicating that MPLS forwarding is not configured:

router#show mpls interface
no MPLS apps enabled or MPLS not enabled on any interfaces

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 the 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

Devices that are not configured for MPLS are not vulnerable.

The following products have been confirmed not to be affected by these vulnerabilities:

  • Cisco IOS XR Software

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

Details

The packet handling nodes in an MPLS network are called provider routers (P routers) and provider edge routers (PE routers) and are configured with MPLS. Both P and PE routers are vulnerable to both the vulnerabilities disclosed in this advisory.

In networks that have MPLS enabled and could carry MPLS label switched packets with IPv6 payloads, the device may crash when processing MPLS label switched packets with specific IPv6 payloads. Typical deployment scenarios that would be affected by either vulnerability would be Cisco IPv6 Provider Edge Router (6PE) or IPv6 VPN Provider Edge Router (6VPE).

Crafted IPv6 Packet May Cause MPLS-Configured Device to Reload

A crafted IPv6 packet may cause the device to crash when the packet is processed by Cisco IOS Software because the MPLS TTL has expired. The crafted packet used to exploit this vulnerability would be silently discarded in Cisco IOS Software if received on an interface where the packet did not have an MPLS label.

This vulnerability is documented in Cisco bug ID CSCto07919 (registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2011-3274.

ICMPv6 Packet May Cause MPLS-Configured Device to Reload

A valid ICMPv6 packet may cause the device to crash when the packet is processed by Cisco IOS Software because the MPLS TTL has expired. The packet used to exploit this vulnerability would not affect Cisco IOS Software if received on an interface where the packet did not have an MPLS label.

This vulnerability is documented in Cisco bug ID CSCtj30155 (registered customers only) and has been assigned CVE ID CVE-2011-3282.

Vulnerability Scoring Details

Cisco has provided scores for the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this Security Advisory is done in accordance with CVSS version 2.0.

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

Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks.

Cisco has provided an FAQ to answer additional questions regarding CVSS at
http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html .

Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at
http://intellishield.cisco.com/security/alertmanager/cvss .



CSCto07919

Calculate the environmental score of CSCto07919

CVSS Base Score - 6.1

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Adjacent Network

Low

None

None

None

Complete

CVSS Temporal Score - 5.0

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed




CSCtj30155

Calculate the environmental score of CSCtj30155

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 - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed


Impact

Successful exploitation of these vulnerabilities may cause the device to reload. Repeated exploitation could result in a sustained denial of service condition.

Software Versions and Fixes

When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.

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

Additionally, the Cisco IOS Software Checker is available on the Cisco Security Intelligence Operations (SIO) portal at http://tools.cisco.com/security/center/selectIOSVersion.x. It provides several features for checking which Security Advisories affect specified versions of Cisco IOS Software.

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 For This Advisory column. The First Fixed Release for All Advisories in the September 2011 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.

Major Release

     Availability of Repaired Releases

Affected 12.0-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

There are no affected 12.0-based releases

Affected 12.1-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

12.1E

Not vulnerable

12.2(18)SXF17b

Affected 12.2-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

12.2

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2B

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2BC

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2BW

Not vulnerable

Not vulnerable

12.2BX

Not vulnerable

Vulnerable; first fixed in Release 12.2SB

12.2BY

Not vulnerable

Not vulnerable

12.2BZ

Not vulnerable

Not vulnerable

12.2CX

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2CY

Not vulnerable

Not vulnerable

12.2CZ

Not vulnerable

Vulnerable; first fixed in Release 12.2SB

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

Releases up to and including 12.2(20)EW4 are not vulnerable.

12.2EWA

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2EX

Not vulnerable

12.2(55)EX3

12.2EY

Not vulnerable

12.2(58)EY

12.2EZ

Not vulnerable

Vulnerable; migrate to any release in 15.0SE

12.2FX

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2FY

Not vulnerable

Vulnerable; first fixed in Release 12.2EX

12.2FZ

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2IRA

Not vulnerable

Vulnerable; migrate to any release in 12.2IRG

12.2IRB

Not vulnerable

Vulnerable; migrate to any release in 12.2IRG

12.2IRC

Not vulnerable

Vulnerable; migrate to any release in 12.2IRG

12.2IRD

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IRE

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IRF

Not vulnerable

Vulnerable; migrate to any release in 12.2IRG

12.2IRG

Not vulnerable

Not vulnerable

12.2IXA

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXB

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXC

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXD

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXE

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXF

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXG

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2IXH

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2JA

Not vulnerable

Not vulnerable

12.2JK

Not vulnerable

Not vulnerable

12.2MB

Not vulnerable

Not vulnerable

12.2MC

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2MRA

Not vulnerable

Vulnerable; first fixed in Release 12.2SRD

12.2MRB

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2S

Not vulnerable

Releases prior to 12.2(30)S are vulnerable; Releases 12.2(30)S and later are not vulnerable. First fixed in Release 12.2SB

12.2SB

Not vulnerable

12.2(31)SB20

12.2(33)SB10

12.2SBC

Not vulnerable

Vulnerable; first fixed in Release 12.2SB

12.2SCA

Not vulnerable

Vulnerable; first fixed in Release 12.2SCC

12.2SCB

Not vulnerable

Vulnerable; first fixed in Release 12.2SCC

12.2SCC

Not vulnerable

12.2(33)SCC7

12.2SCD

Not vulnerable

12.2(33)SCD6

12.2SCE

Not vulnerable

12.2(33)SCE1

12.2(33)SCE2

12.2SCF

Not vulnerable

Not vulnerable

12.2SE

Not vulnerable

12.2(55)SE3

12.2(58)SE

12.2SEA

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2SEB

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2SEC

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2SED

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2SEE

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2SEF

Not vulnerable

Vulnerable; first fixed in Release 12.2SE

12.2SEG

Not vulnerable

Releases prior to 12.2(25)SEG4 are vulnerable; Releases 12.2(25)SEG4 and later are not vulnerable. First fixed in Release 12.2EX

12.2SG

Not vulnerable

Releases prior to 12.2(53)SG4 are vulnerable; Releases 12.2(53)SG4 and later are not vulnerable.

12.2SGA

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2SL

Not vulnerable

Not vulnerable

12.2SM

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2SO

Not vulnerable

Not vulnerable

12.2SQ

Not vulnerable

12.2(50)SQ3

12.2SRA

Not vulnerable

Vulnerable; first fixed in Release 12.2SRD

12.2SRB

Not vulnerable

Vulnerable; first fixed in Release 12.2SRD

12.2SRC

Not vulnerable

Vulnerable; first fixed in Release 12.2SRD

12.2SRD

Not vulnerable

12.2(33)SRD6

12.2SRE

12.2(33)SRE4

12.2(33)SRE4

12.2STE

Not vulnerable

Not vulnerable

12.2SU

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2SV

Not vulnerable

Releases prior to 12.2(29a)SV are vulnerable; Releases 12.2(29a)SV and later are not vulnerable. Migrate to any release in 12.2SVD

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

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2SX

Not vulnerable

Vulnerable; first fixed in Release 12.2SXF

12.2SXA

Not vulnerable

Vulnerable; first fixed in Release 12.2SXF

12.2SXB

Not vulnerable

Vulnerable; first fixed in Release 12.2SXF

12.2SXD

Not vulnerable

Vulnerable; first fixed in Release 12.2SXF

12.2SXE

Not vulnerable

Vulnerable; first fixed in Release 12.2SXF

12.2SXF

Not vulnerable

12.2(18)SXF17b

12.2SXH

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2SXI

Not vulnerable

12.2(33)SXI6

12.2SXJ

Not vulnerable

12.2(33)SXJ1

12.2SY

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2SZ

Not vulnerable

Vulnerable; first fixed in Release 12.2SB

12.2T

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2TPC

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2XA

Not vulnerable

Not vulnerable

12.2XB

Not vulnerable

Vulnerable; first fixed in Release 12.4

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

12.2XN

Not vulnerable

Not vulnerable

12.2XNA

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

12.2XNB

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

12.2XNC

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

12.2XND

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

12.2XNE

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

12.2XNF

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

12.2XO

Not vulnerable

Releases prior to 12.2(54)XO are vulnerable; Releases 12.2(54)XO and later 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

Vulnerable; first fixed in Release 12.4

12.2YB

Not vulnerable

Not vulnerable

12.2YC

Not vulnerable

Not vulnerable

12.2YD

Not vulnerable

Not vulnerable

12.2YE

Not vulnerable

Not vulnerable

12.2YF

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YG

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YH

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YJ

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YK

Not vulnerable

Not vulnerable

12.2YL

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YM

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2YN

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YO

Not vulnerable

Not vulnerable

12.2YP

Not vulnerable

Not vulnerable

12.2YQ

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YR

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YS

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YT

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YU

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YV

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YW

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YX

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YY

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2YZ

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2ZA

Not vulnerable

Vulnerable; first fixed in Release 12.2SXF

12.2ZB

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2ZC

Not vulnerable

Not vulnerable

12.2ZD

Not vulnerable

Not vulnerable

12.2ZE

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2ZF

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2ZG

Not vulnerable

Not vulnerable

12.2ZH

Not vulnerable

Vulnerable; first fixed in Release 12.4

12.2ZJ

Not vulnerable

Not vulnerable

12.2ZL

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2ZP

Not vulnerable

Not vulnerable

12.2ZU

Not vulnerable

Vulnerable; first fixed in Release 12.2SXH

12.2ZX

Not vulnerable

Not vulnerable

12.2ZY

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

12.2ZYA

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

Affected 12.3-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

There are no affected 12.3-based releases

Affected 12.4-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

There are no affected 12.4-based releases

Affected 15.0-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

15.0M

15.0(1)M7

15.0(1)M7

15.0MR

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

15.0MRA

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

15.0S

15.0(1)S4

Cisco IOS XE devices: see Cisco IOS-XE Software Availability

15.0(1)S4

Cisco IOS XE devices: see Cisco IOS-XE Software Availability

15.0SA

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

15.0SE

Not vulnerable

Not vulnerable

15.0SG

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

15.0XA

Vulnerable; first fixed in Release 15.1T

Vulnerable; first fixed in Release 15.1T

15.0XO

See Cisco IOS-XE Software Availability

See Cisco IOS-XE Software Availability

Affected 15.1-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

15.1EY

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

15.1GC

Vulnerable; first fixed in Release 15.1T

Vulnerable; first fixed in Release 15.1T

15.1M

15.1(4)M1

15.1(4)M2; Available on 30-SEP-11

15.1MR

Not vulnerable

Vulnerable; contact your support organization per the instructions in the Obtaining Fixed Software section of this advisory.

15.1S

15.1(2)S2

15.1(3)S

Cisco IOS XE devices: see Cisco IOS-XE Software Availability

15.1(2)S2

15.1(3)S

Cisco IOS XE devices: see Cisco IOS-XE Software Availability

15.1T

15.1(1)T4; Available 09-DEC-2011

15.1(2)T4

15.1(3)T2

15.1(1)T4; Available 09-DEC-2011

15.1(2)T4

15.1(3)T2

15.1XB

Vulnerable; first fixed in Release 15.1T

Vulnerable; first fixed in Release 15.1T

Affected 15.2-Based Releases

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

There are no affected 15.2-based releases

Cisco IOS XE Software

Cisco IOS XE Software is affected by the vulnerability disclosed in this document.

Cisco IOS XE Release

First Fixed Release For This Advisory

First Fixed Release for All Advisories in the September 2011 Bundled Publication

2.1.x

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

2.2.x

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

2.3.x

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

2.4.x

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

2.5.x

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

2.6.x

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

3.1.xS

3.1.4S

Vulnerable; migrate to 3.3.2S or later

3.1.xSG

Not vulnerable

Vulnerable; migrate to 3.2.0SG or later

3.2.xS

Vulnerable; migrate to 3.3.2S or later

Vulnerable; migrate to 3.3.2S or later

3.2.xSG

Not vulnerable

Not vulnerable

3.3.xS

3.3.2S

3.3.2S

3.4.xS

Not vulnerable

Not vulnerable

For mapping of Cisco IOS XE to Cisco IOS releases, please refer to the Cisco IOS XE 2 Release Notes, Cisco IOS XE 3S Release Notes, and Cisco IOS XE 3SG Release Notes.

Cisco IOS XR Software

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

Cisco IOS XR Software is not affected by any of the vulnerabilities in the September 2011 bundled publication.



Workarounds

For both vulnerabilities the following workaround applies:

Disabling MPLS TTL Propagation

Disabling MPLS TTL propagation will prevent exploitation of these vulnerabilities. MPLS TTL propagation will have to be disabled on all PE routers in the MPLS domain. To disable MPLS TTL propagation, enter the global configuration command no mpls ip propagate-ttl. If only no mpls ip propagate-ttl forward is configured, the vulnerabilities could still be exploited from within the MPLS domain.

For more information about the MPLS TTL propagation command, refer to the configuration guide at http://www.cisco.com/en/US/docs/ios/mpls/command/reference/mp_m1.html#wp1013846

Obtaining Fixed Software

Cisco has released free software updates that address these vulnerabilities. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment.

Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html , or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml .

Do not contact psirt@cisco.com or security-alert@cisco.com for software upgrades

Customers with Service Contracts

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

Customers Using Third-Party Support Organizations

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

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

Customers Without Service Contracts

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

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

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

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

Exploitation and Public Announcements

The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities described in this advisory.

These vulnerabilities were discovered when handling customer support calls.

Status of This Notice: Final

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

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


Distribution

This advisory is posted on Cisco's worldwide website at:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110928-ipv6mpls

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

  • cust-security-announce@cisco.com
  • first-teams@first.org
  • bugtraq@securityfocus.com
  • vulnwatch@vulnwatch.org
  • cisco@spot.colorado.edu
  • cisco-nsp@puck.nether.net
  • full-disclosure@lists.grok.org.uk
  • comp.dcom.sys.cisco@newsgate.cisco.com

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


Revision History

Revision 1.2

2011-September-30

Updated Cisco IOS Software table bundled publication first fixed information.

Revision 1.1

2011-September-28

Added missing information in fixed Cisco IOS Software table for releases 15.0S and 15.1S.

Revision 1.0

2011-September-28

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/web/about/security/psirt/security_vulnerability_policy.html. This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt.


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