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FW: Cisco Security Advisory: Cisco IOS XR MPLS Vulnerabilities

  • From: Irwin Lazar <ilazar@burtongroup.com>
  • Date: Wed, 19 Apr 2006 11:43:11 -0400
  • Resent-Date: Wed, 19 Apr 2006 11:43:17 -0400
  • User-Agent: Microsoft-Entourage/11.2.3.060209
  • X-Scanned-By: MIMEDefang 2.53 on 209.239.41.31

FYI:

------ Forwarded Message
> From: Cisco Systems Product Security Incident Response Team <psirt@cisco.com>
> Reply-To: <psirt@cisco.com>
> Date: Wed, 19 Apr 2006 17:00:00 +0200
> To: <nanog@merit.edu>
> Cc: <psirt@cisco.com>
> Subject: Cisco Security Advisory: Cisco IOS XR MPLS Vulnerabilities
> 
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Cisco Security Advisory: Cisco IOS XR MPLS Vulnerabilities
> 
> Advisory ID: cisco-sa-20060419-xr
> 
> http://www.cisco.com/warp/public/707/cisco-sa-20060419-xr.shtml
> 
> Revision 1.0
> 
> For Public Release 2006 April 19 1500 UTC (GMT)
> 
> - ---------------------------------------------------------------------
> 
> Contents
> ========
> 
>     Summary
>     Affected Products
>     Details
>     Impact
>     Software Version and Fixes
>     Workarounds
>     Obtaining Fixed Software
>     Exploitation and Public Announcements
>     Status of this Notice: FINAL
>     Distribution
>     Revision History
>     Cisco Security Procedures
> 
> - ---------------------------------------------------------------------
> 
> Summary
> =======
> 
> Multiple Multi Protocol Label Switching (MPLS) related
> vulnerabilities exist on Cisco IOS  XR. Only systems that are running
> Cisco IOS XR and configured for MPLS are affected by these
> vulnerabilities.
> 
> Upon successful exploitation a Modular Services Card (MSC) on a Cisco
> Carrier Routing System 1 (CRS-1) or a Line Card (LC) on a Cisco 12000
> series router may reload affecting switched traffic.
> 
> Cisco has made free software available to address this vulnerability
> for affected customers.
> 
> This advisory is posted at
> http://www.cisco.com/warp/public/707/cisco-sa-20060419-xr.shtml.
> 
> Affected Products
> =================
> 
> Vulnerable Products
> +------------------
> 
> Only systems that are running Cisco IOS XR and configured for MPLS
> are affected by this vulnerability.
> 
> Systems that are running Cisco IOS XR and configured for MPLS can be
> identified by the show mpls interfaces command. A sample output of
> this command on a CRS-1 that is configured for MPLS is given below.
> 
>       RP/0/RP1/CPU0:crs1#show mpls interfaces
>       Interface                  LDP      Tunnel   Enabled
>       -------------------------- -------- -------- --------
>       POS0/2/0/0                 Yes      Yes      Yes
>       POS0/2/0/1                 No       Yes      Yes
>       POS0/2/0/2                 Yes      No       Yes
>       POS0/2/0/3                 Yes      Yes      Yes
>       GigabitEthernet0/3/1/0     Yes      No       Yes
>       GigabitEthernet0/3/1/3     Yes      No       Yes
>       POS0/3/0/1                 Yes      Yes      Yes
>       TenGigE0/6/0/0             Yes      No       Yes
>       RP/0/RP1/CPU0:crs#
> 
> 
> In the above output, the fourth column labeled Enabled identifies
> MPLS enabled interfaces.
> 
> Products Confirmed Not Vulnerable
> +--------------------------------
> 
> Cisco IOS XR only runs on CRS-1 or Cisco 12000 series routers. Other
> Cisco products, including systems that run Cisco IOS are not
> affected.
> 
> Details
> =======
> 
> Cisco IOS XR Software is a member of the Cisco IOS Software Family
> that uses a microkernel based distributed operating system
> infrastructure. Cisco IOS XR runs both on Cisco CRS-1 and Cisco 12000
> series routers.
> 
> More information on Cisco IOS XR can be found at the following URL:
> 
> http://www.cisco.com/en/US/products/ps5845/index.html
> 
> Modular Services Cards (MSC), also called the line cards are Layer-3
> forwarding engines on Cisco CRS-1. An MSC is paired with a physical
> layer interface module (PLIM) which provides layer-1 and layer-2
> services.
> 
> More information on Cisco CRS-1 architecture can be found at the
> following URL:
> 
> http://www.cisco.com/en/US/products/ps5763/index.html
> 
> Specific MPLS packets that are switched by a Cisco CRS-1 or a 12000
> series system will restart the NetIO process. If the NetIO process is
> restarted several times consecutively, the line card will reload
> causing a Denial of Service (DoS) condition for the traffic that is
> being switched on that line card.
> 
> MPLS packets will be forwarded through the MPLS network. Therefore,
> packets that can trigger this vulnerability can be sent from remote
> systems that are in the MPLS network. Such packets can not be
> received on interfaces that are not configured for MPLS.
> 
> This vulnerability is addressed by the following Cisco bug IDs:
> 
>   * CSCsd15970 -- MSC crash upon receipt of specific MPLS packets
>     This bug only affects CRS-1 and does not affect Cisco 12000
>     series routers that are running Cisco IOS XR.
> 
>   * CSCsd55531 -- MPLS packet handling problems
>     This bug only affects CRS-1 and does not affect Cisco 12000
>     series routers that are running Cisco IOS XR.
> 
>   * CSCsc77475 -- Line card crash upon receipt of specific MPLS
>     packets
>     This bug affects both CRS-1 and Cisco 12000 series routers that
>     are running Cisco IOS XR.
> 
> 
> Impact
> ======
> 
> Successful exploitation of the vulnerability may result in a reload
> of the Modular Services Card (MSC) on a CRS-1 or the line cards on a
> Cisco 12000 series router. Repeated exploitation could result in a
> sustained DoS attack.
> 
> Software Version 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.
> 
> +---------------------------------------+
> | Cisco IOS XR  | SMU ID                |
> | Version       |                       |
> |---------------+-----------------------|
> | 3.2.0         | AA01447               |
> |---------------+-----------------------|
> | 3.2.1         | AA01446               |
> |---------------+-----------------------|
> | 3.2.2         | AA01448               |
> |---------------+-----------------------|
> | 3.2.3 for     | AA01444               |
> | CRS-1         |                       |
> |---------------+-----------------------|
> | 3.2.3 for PRP | AA01451               |
> |---------------+-----------------------|
> | 3.2.4         | AA01449               |
> |---------------+-----------------------|
> | 3.2.50        | AA01450               |
> |---------------+-----------------------|
> | 3.3           | Cisco IOS XR 3.3 is   |
> |               | not vulnerable        |
> +---------------------------------------+
> 
> Workarounds
> ===========
> 
> There is no workaround to mitigate the effects of these
> vulnerabilities.
> 
> Obtaining Fixed Software
> ========================
> 
> Cisco will make free software available to address this vulnerability
> for affected customers. This advisory will be updated as fixed
> software becomes available. 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/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.
> 
> Do not contact either "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 agreement 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 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.
> 
>   * +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
> 
> 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.
> 
> Refer to 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.
> 
> Exploitation and Public Announcements
> =====================================
> 
> The Cisco PSIRT is not aware of any public announcements or malicious
> use of the vulnerability described in this advisory.
> 
> This vulnerability was reported to Cisco by a customer.
> 
> 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://www.cisco.com/warp/public/707/cisco-sa-20060419-xr.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.
> 
>   * 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 |               | Initial    |
> | 1.0      | 2006-April-19 | 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.htm
> l. 
> 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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------ End of Forwarded Message

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