[apops] Cisco Security Advisory: Cisco IOS Software Object-group Access

  • To: apops at apops dot net
  • Subject: [apops] Cisco Security Advisory: Cisco IOS Software Object-group Access Control List Bypass Vulnerability
  • From: Cisco Systems Product Security Incident Response Team <psirt at cisco dot com>
  • Date: Wed, 23 Sep 2009 12:15:00 -0400
  • Cc: psirt at cisco dot com
  • Delivered-to: apops at mailman dot apnic dot net
  • List-archive: <http://mailman.apnic.net/mailing-lists/apops>
  • List-help: <mailto:apops-request@apops.net?subject=help>
  • List-id: Asia Pacific Operators Forum <apops.apops.net>
  • List-post: <mailto:apops@apops.net>
  • List-subscribe: <http://mailman.apnic.net/mailman/listinfo/apops>, <mailto:apops-request@apops.net?subject=subscribe>
  • List-unsubscribe: <http://mailman.apnic.net/mailman/listinfo/apops>, <mailto:apops-request@apops.net?subject=unsubscribe>
  • Prevent-nondelivery-report:
  • Reply-to: psirt@cisco.com
  • Sender: nobody@cisco.com
    • Hash: SHA1
      
      Cisco Security Advisory: Cisco IOS Software Object-group Access
      Control List Bypass Vulnerability
      
      Advisory ID: cisco-sa-20090923-acl
      
      Revision 1.0
      
      For Public Release 2009 September 23
      
      +---------------------------------------------------------------------
      
      Summary
      =======
      
      A vulnerability exists in Cisco IOS® software where an
      unauthenticated attacker could bypass access control policies when
      the Object Groups for Access Control Lists (ACLs) feature is used.
      Cisco has released free software updates that address this
      vulnerability. There are no workarounds for this vulnerability other
      than disabling the Object Groups for ACLs feature.
      
      This advisory is posted at:
      
      http://www.cisco.com/warp/public/707/cisco-sa-20090923-acl.shtml
      
      Note: The September 23, 2009, Cisco IOS Security Advisory bundled
      publication includes eleven Security Advisories. Ten of the
      advisories address vulnerabilities in Cisco IOS Software, and one
      advisory addresses a vulnerability in Cisco Unified Communications
      Manager. Each advisory lists the releases that correct the
      vulnerability or vulnerabilities detailed in the advisory. The
      following table lists releases that correct all Cisco IOS Software
      vulnerabilities that have been published on September 23, 2009, or
      earlier.
      
      http://www.cisco.com/warp/public/707/cisco-sa-20090923-bundle.shtml
      
      Individual publication links are in "Cisco Event Response: Semiannual
      Cisco IOS Software Advisory Bundled Publication" at the following
      link:
      
      http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep09.html
      
      Affected Products
      =================
      
      Vulnerable Products
      +------------------
      
      Any Cisco device configured with ACLs using the object group feature
      and running an affected Cisco IOS software version is affected by
      this vulnerability.
      
      Note: The Object Groups for ACLs feature was introduced in Cisco IOS
      software version 12.4(20)T.
      
      To verify whether object groups are configured in a Cisco IOS device,
      use the "show object-group" command in user EXEC or privileged EXEC
      mode. The following example displays a sample output from the "show
      object-group" command when object groups are configured:
      
          Router# show object-group
          Network object group my_host_group
           host 172.18.104.123
          
          Service object group my_allowed_services
           tcp eq www
           tcp eq 443
      
      Alternatively, administrators can also use the "show running config |
      include ^ (permit|deny) .*object-group" command to verify whether
      object groups are configured, as shown in the following example:
      
          Router#show running-config | include ^ (permit|deny) .*object-group
           permit object-group my_allowed_services host 10.10.1.1 host 10.20.1.1
           permit tcp any object-group my_host_group eq 22
      
      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 12.3(26) with an installed image name of
      C2500-IS-L:
      
          Router#show version
          Cisco Internetwork Operating System Software
          IOS (tm) 2500 Software (C2500-IS-L), Version 12.3(26), RELEASE SOFTWARE (fc2)
          Technical Support: http://www.cisco.com/techsupport
          Copyright (c) 1986-2008 by cisco Systems, Inc.
          Compiled Mon 17-Mar-08 14:39 by dchih
          
          
          !--- output truncated
          
      
      The following example identifies a Cisco product that is running
      Cisco IOS Software Release 12.4(20)T with an installed image name of
      C1841-ADVENTERPRISEK9-M:
      
          Router#show version
          Cisco IOS Software, 1841 Software (C1841-ADVENTERPRISEK9-M), Version 12.4(20)T, RELEASE SOFTWARE (fc3)
          Technical Support: http://www.cisco.com/techsupport
          Copyright (c) 1986-2008 by Cisco Systems, Inc.
          Compiled Thu 10-Jul-08 20:25 by prod_rel_team
          
          
          !--- output truncated
          
      
      Products Confirmed Not Vulnerable
      +--------------------------------
      
      Cisco devices that are not configured with object groups are not
      vulnerable.
      
      Cisco IOS XE Software and Cisco IOS XR Software are not affected by
      this vulnerability.
      
      No other Cisco products are currently known to be affected by this
      vulnerability.
      
      Details
      =======
      
      In Cisco IOS Software an object group can contain a single object
      (such as a single IP address, network, or subnet) or multiple objects
      (such as a combination of multiple IP addresses, networks, or
      subnets). In an ACL that is based on an object group, administrators
      can create a single access control entry (ACE) that uses an object
      group name instead of creating many ACEs, which each would require a
      different IP address. A similar object group, such as a protocol port
      group, can be extended to limit access to a set of applications for a
      user group to a server group.
      
      A vulnerability exists in Cisco IOS Software that could allow an
      unauthenticated attacker to bypass access control policies when the
      Object Groups for ACLs feature is used.
      
      Note: The Object Groups for ACLs feature was introduced in Cisco IOS
      software version 12.4(20)T.
      
      This vulnerability is documented in the following Cisco Bug IDs:
      
        * CSCsx07114
        * CSCsu70214
        * CSCsw47076
        * CSCsv48603
        * CSCsy54122
        * CSCsu50252
      
      This vulnerability has been assigned Common Vulnerabilities and
      Exposures (CVE) identifier CVE-2009-2862.
      
      Vulnerability Scoring Details
      =============================
      
      Cisco has provided scores for the vulnerability 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
      
      CSCsx07114, CSCsu70214, CSCsw47076, CSCsv48603, CSCsy54122, CSCsu50252 -
      Object-group Access Control List Bypass
      
      CVSS Base Score - 4.3
      
      Access Vector           - Network
      Access Complexity       - Medium
      Authentication          - None
      Confidentiality Impact  - Parital
      Integrity Impact        - None
      Availability Impact     - none
      
      CVSS Temporal Score - 3.6
      
      Exploitability          - Functional
      Remediation Level       - Official-Fix
      Report Confidence       - Confirmed
      
      Impact
      ======
      
      Successful exploitation of the vulnerability may allow an attacker to
      access resources that should be protected by the Cisco IOS device.
      
      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.
      
      Each row of the Cisco IOS software table (below) names a Cisco IOS
      release train. If a given release train is vulnerable, then the
      earliest possible releases that contain the fix (along with the
      anticipated date of availability for each, if applicable) are listed
      in the "First Fixed Release" column of the table. The "Recommended
      Release" column indicates the releases which have fixes for all the
      published vulnerabilities at the time of this Advisory. 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. Cisco recommends upgrading to a release equal to or
      later than the release in the "Recommended Releases" column of the
      table.
      
      +-------------------------------------------------------------------+
      |   Major    |          Availability of Repaired Releases           |
      |  Release   |                                                      |
      |------------+------------------------------------------------------|
      |  Affected  |                                       | Recommended  |
      | 12.0-Based |          First Fixed Release          |   Release    |
      |  Releases  |                                       |              |
      |-------------------------------------------------------------------|
      | There are no affected 12.0 based releases.                        |
      |-------------------------------------------------------------------|
      |  Affected  |                                       | Recommended  |
      | 12.1-Based |          First Fixed Release          |   Release    |
      |  Releases  |                                       |              |
      |-------------------------------------------------------------------|
      | There are no affected 12.1 based releases.                        |
      |-------------------------------------------------------------------|
      |  Affected  |                                       | Recommended  |
      | 12.2-Based |          First Fixed Release          |   Release    |
      |  Releases  |                                       |              |
      |-------------------------------------------------------------------|
      | There are no affected 12.1 based releases.                        |
      |-------------------------------------------------------------------|
      |  Affected  |                                       | Recommended  |
      | 12.3-Based |          First Fixed Release          |   Release    |
      |  Releases  |                                       |              |
      |-------------------------------------------------------------------|
      | There are no affected 12.3 based releases.                        |
      |-------------------------------------------------------------------|
      |  Affected  |                                       | Recommended  |
      | 12.4-Based |          First Fixed Release          |   Release    |
      |  Releases  |                                       |              |
      |------------+---------------------------------------+--------------|
      | 12.4       | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      |            | Vulnerable; Contact your support      |              |
      | 12.4GC     | organization per the instructions in  |              |
      |            | Obtaining Fixed Software section of   |              |
      |            | this advisory                         |              |
      |------------+---------------------------------------+--------------|
      | 12.4JA     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JDA    | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JDC    | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JDD    | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JK     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JL     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JMA    | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JMB    | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4JX     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      |            |                                       | 12.4(11)MD9  |
      |            |                                       |              |
      | 12.4MD     | 12.4(22)MD1                           | 12.4(15)MD3  |
      |            |                                       |              |
      |            |                                       | 12.4(22)MD1  |
      |------------+---------------------------------------+--------------|
      | 12.4MDA    | 12.4(22)MDA1                          | 12.4(22)MDA1 |
      |------------+---------------------------------------+--------------|
      | 12.4MR     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4SW     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      |            |                                       | 12.4(20)T4   |
      |            | 12.4(22)T2                            |              |
      |            |                                       | 12.4(22)T3   |
      | 12.4T      | 12.4(20)T4                            |              |
      |            |                                       | 12.4(24)T2;  |
      |            | 12.4(24)T1                            | Available on |
      |            |                                       | 23-OCT-2009  |
      |------------+---------------------------------------+--------------|
      | 12.4XA     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XB     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XC     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XD     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XE     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XF     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XG     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XJ     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XK     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XL     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XM     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XN     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XP     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XQ     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XR     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XT     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XV     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XW     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      | 12.4XY     | Not Vulnerable                        |              |
      |------------+---------------------------------------+--------------|
      |            |                                       | 12.4(20)T4   |
      |            |                                       |              |
      |            |                                       | 12.4(22)T3   |
      | 12.4XZ     | Vulnerable; first fixed in 12.4T      |              |
      |            |                                       | 12.4(24)T2;  |
      |            |                                       | Available on |
      |            |                                       | 23-OCT-2009  |
      |------------+---------------------------------------+--------------|
      |            |                                       | 12.4(22)T3   |
      |            |                                       |              |
      | 12.4YA     | Vulnerable; first fixed in 12.4T      | 12.4(24)T2;  |
      |            |                                       | Available on |
      |            |                                       | 23-OCT-2009  |
      |------------+---------------------------------------+--------------|
      | 12.4YB     | 12.4(22)YB4                           | 12.4(22)YB4  |
      |------------+---------------------------------------+--------------|
      | 12.4YD     | 12.4(22)YD1                           | 12.4(22)YD1  |
      |------------+---------------------------------------+--------------|
      | 12.4YE     | 12.4(22)YE1                           | 12.4(22)YE1  |
      |------------+---------------------------------------+--------------|
      | 12.4YG     | Not Vulnerable                        |              |
      +-------------------------------------------------------------------+
      
      Note: No Cisco IOS-XE or Cisco IOS Software Modularity releases are
      affected by this vulnerability.
      
      Workarounds
      ===========
      
      There are no workarounds for this vulnerability other than disabling
      the Object Groups for ACLs feature.
      
      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 at cisco dot com or security-alert at cisco dot 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 at cisco dot 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 vulnerability described in this advisory.
      
      This vulnerability was found 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's worldwide website at:
      
      http://www.cisco.com/warp/public/707/cisco-sa-20090923-acl.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 at cisco dot com
        * first-bulletins at lists dot first dot org
        * bugtraq at securityfocus dot com
        * vulnwatch at vulnwatch dot org
        * cisco at spot dot colorado dot edu
        * cisco-nsp at puck dot nether dot net
        * full-disclosure at lists.grok dot org dot uk
        * comp.dcom.sys.cisco at newsgate dot cisco dot 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      | 2009-September-23 | 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
      -----BEGIN PGP SIGNATURE-----
      
      iD8DBQFKukF586n/Gc8U/uARAuXEAJ99dU6Wi1fZMY1yNgedSCx4/+0p8wCeOSKF
      HmMwzq017QkqDzBFo/JH6DQ=
      =XJAG
      -----END PGP SIGNATURE-----