Cisco Security Advisory

Cisco IOS XR Software Route Processor Denial of Service Vulnerability

High
Advisory ID:
cisco-sa-20120530-iosxr
First Published:
2012 May 30 16:00 GMT
Last Updated: 
2012 August 23 20:37 GMT
Version 2.1:
Final
Workarounds:
See below
CVE-2012-2488
CVSS Score:
Base 7.8, Temporal 6.4Click Icon to Copy Verbose Score
AV:N/AC:L/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C
CVE-2012-2488

Summary

  • Cisco IOS XR Software contains a vulnerability when handling crafted packets that may result in a denial of service condition. The vulnerability only exists on Cisco 9000 Series Aggregation Services Routers (ASR) Route Switch Processor (RSP-4G and RSP-8G), Route Switch Processor 440 (RSP440), and Cisco Carrier Routing System (CRS) Performance Route Processor (PRP). The vulnerability is a result of improper handling of crafted packets and could cause the route processor, which processes the packets, to be unable to transmit packets to the fabric.

    Cisco has released software updates that address this vulnerability. This advisory is available at the following link:
    http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120530-iosxr

Affected Products

  • This vulnerability affects IOS XR Software version 4.2.0 running on the Cisco ASR 9000 Series RSP440 and IOS XR Software versions prior to 4.2.0 running on the Cisco ASR 9000 Series RSP-4G or RSP-8G. It also affects IOS XR Software versions 4.0.3, 4.0.4, 4.1.0, 4.1.1, 4.1.2, and 4.2.0 running on the CRS Performance Route Processor.

    Vulnerable Products

    To determine the Cisco IOS XR 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 XR Software by displaying text similar to "Cisco IOS XR Software". The software version is displayed after the text "Cisco IOS XR Software".

    The following example identifies a Cisco ASR 9000 series device that is running Cisco IOS XR Software Release 4.2.0:
    RP/0/RSP1/CPU0:ASR9006-D#show version | inc Cisco IOS XR Software
Fri Apr 27 22:40:32.486 UTC
    Cisco IOS XR Software, Version 4.2.0[Default]
    The following example identifies a Cisco CRS series device that is running Cisco IOS XR Software Release 4.0.4:
    RP/0/RP0/CPU0:CRS-G#show version | inc Cisco IOS XR Software
Fri Apr 27 22:28:14.304 UTC
Cisco IOS XR Software, Version 4.0.4[Default]
    Additional information about Cisco IOS XR Software release naming conventions is available in "White Paper: Cisco IOS Reference Guide" at the following link: http://www.cisco.com/web/about/security/intelligence/ios-ref.html#9

    Additional information about Cisco IOS XR Software time-based release model is available in "White Paper: Guidelines for Cisco IOS XR Software" at the following link: http://www.cisco.com/en/US/prod/collateral/iosswrel/ps8803/ps5845/product_bulletin_c25-478699.html

    In order to determine whether a Cisco ASR 9000 series device with affected software is using an RSP440, the following command can be run:
    RP/0/RSP0/CPU0:ASR9006-D#show inventory all | include Route Switch Processor
    Thu May  3 18:50:46.129 UTC
    NAME: "module 0/RSP0/CPU0", DESCR: "ASR9K Route Switch Processor with 440G/slot Fabric and 6GB"
    NAME: "module 0/RSP1/CPU0", DESCR: "ASR9K Route Switch Processor with 440G/slot Fabric and 6GB"
    Only devices that are equipped with Performance Route Processors are affected. In order to determine whether a Cisco CRS series device with affected software is using a Performance Route Processor, the following command can be run:
    RP/0/RP0/CPU0:CRS-G#show inventory all | include Performance Route Processor
    Wed May  2 14:49:06.994 EDT
    NAME: "0/RP0/*", DESCR: "Cisco CRS Series 8 Slots 12 GB Performance Route Processor"
    NAME: "0/RP1/*", DESCR: "Cisco CRS Series 8 Slots 12 GB Performance Route Processor"

    Products Confirmed Not Vulnerable

    Only Cisco ASR 9000 Series RSP440, RSP-4G, and RSP-8G devices and Cisco Carrier Routing System Performance Route Processor devices are affected.

    No other Cisco products are currently known to be affected by this vulnerability, including other Route Processors such as the Cisco CRS-1 Distributed Route Processor (DRP), RP-A or RP-B.

Details

  • Cisco IOS XR Software is affected by this vulnerability, which is present on two different platforms with specific configurations.

    Vulnerable software versions must be combined with one of the following Route Processors in order to be affected:

    Platform
    		 Route Processor Part ID
     ASR 9000
    		  A9K-RSP440-SE
     ASR 9000
    		  A9K-RSP440-TR
     ASR 9000  A9K-RSP-4G
     ASR 9000  A9K-RSP-8G
     CRS  CRS-8-PRP-6G
     CRS  CRS-8-PRP-12G
     CRS  CRS-16-PRP-6G
     CRS  CRS-16-PRP-12G


    This vulnerability has been documented in Cisco Bug IDs CSCty94537 and CSCua63591 (ASR 9000) and CSCtz62593 (CRS) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2012-2488.

    Cisco IOS XR Software Route Processor Denial of Service Vulnerability

    Cisco IOS XR Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

    The vulnerability is due to improper processing of crafted packets by Cisco 9000 Series Aggregation Services Routers (ASR) Route Switch Processor (RSP-4G or RSP-8G), Route Switch Processor 440 (RSP440), Cisco CRS 16-Slot Line Card Chassis Route Processor B (RP-B), or Carrier Routing System (CRS) Performance Route Processor. An attacker could exploit this vulnerability by sending a crafted packet to a vulnerable system; this vulnerability cannot be triggered by IP traffic transiting a vulnerable device. An exploit could allow the attacker to cause the packets originating on the Route Processor CPU to stop transmitting to the fabric, resulting in a DoS condition.

Workarounds

  • There are no workarounds for the vulnerability described in this document.

Fixed Software

  • 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.

    For IOS XR running on Cisco ASR 9000 Series RSP440, the vulnerability is present in software version 4.2.0 and is fixed with SMU name 4.2.0_asr9k-px_REC_SMUS_2012-05-15.tar.

    For IOS XR running on Cisco ASR 9000 Series RSP-4G or RSP-8G, the vulnerability is present in versions prior to 4.2.0. The following SMUs for ASR 9000 Series RSP-4G or RSP-8G devices correct this vulnerability:

    IOS XR Version
    		SMU ID
    		 SMU Name
     4.0.1  AA06294 
    		 asr9k-p-4.0.1.CSCua63591
     4.0.3  AA06313  asr9k-p-4.0.3.CSCua63591
     4.1.0  AA06306  asr9k-p-4.1.0.CSCua63591
     4.1.1  AA06308  asr9k-p-4.1.1.CSCua63591
     4.1.2  AA06305  asr9k-p-4.1.2.CSCua63591

    For IOS XR running on CRS Performance Route Processor, the vulnerability is present in versions 4.0.3, 4.0.4, 4.1.0, 4.1.1, 4.1.2, and 4.2.0. The following SMUs for CRS series devices correct this vulnerability:

    IOS XR Version
    		SMU ID
    		 SMU Name
    4.0.3
    		AA06162  hfr-px-4.0.3.CSCtz62593
    4.0.4 AA06161  hfr-px-4.0.4.CSCtz62593
    4.1.0 AA06163  hfr-px-4.1.0.CSCtz62593
    4.1.1 AA06164  hfr-px-4.1.1.CSCtz62593
    4.1.2 AA06165  hfr-px-4.1.2.CSCtz62593
    4.2.0 AA06166  hfr-px-4.2.0.CSCtz62593

    This vulnerability will be fixed in IOS XR version 4.2.1 for both Cisco ASR 9000 series devices and CRS series devices.

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 while diagnosing issues encountered in customer networks.

Cisco Security Vulnerability Policy

  • To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

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Revision History

  • Revision 2.1 2012-August-23 Doc updated to correct first published date
    Revision 2.0 2012-August-15 Updated affected platforms to include RSP-4G and RSP-8G on ASR 9000 Series, prior to IOS XR 4.2.0
    Revision 1.1 2012-May-31 Updated Software Versions and Fixes to clarify SMU names and to provide links to relevant Software Downloads pages
    Revision 1.0 2012-May-30 Initial public release
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Cisco Security Vulnerability Policy

  • To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

Subscribe to Cisco Security Notifications