[apops] Cisco Security Advisory: Cisco Content Services Gateway Vulnerab

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  • Subject: [apops] Cisco Security Advisory: Cisco Content Services Gateway Vulnerabilities
  • From: Cisco Systems Product Security Incident Response Team <psirt at cisco dot com>
  • Date: Wed, 26 Jan 2011 10:39:07 -0500
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      Cisco Security Advisory: Cisco Content Services Gateway Vulnerabilities
      Advisory ID: cisco-sa-20110126-csg2
      Revision 1.0
      For Public Release 2011 January 26 1600 UTC (GMT)
      A service policy bypass vulnerability exists in the Cisco Content
      Services Gateway - Second Generation (CSG2), which runs on the
      Cisco Service and Application Module for IP (SAMI). Under certain
      configurations this vulnerability could allow:
        * Customers to access sites that would normally match a billing
          policy to be accessed without being charged to the end customer
        * Customers to access sites that would normally be denied based on
          configured restriction policies
      Additionally, Cisco IOS Software Release 12.4(24)MD1 on the Cisco
      CSG2 contains two vulnerabilities that can be exploited by a remote,
      unauthenticated attacker to create a denial of service condition that
      prevents traffic from passing through the CSG2. These vulnerabilities
      require only a single content service to be active on the Cisco CSG2 and
      can be exploited via crafted TCP packets. A three-way handshake is not
      required to exploit either of these vulnerabilities.
      Workarounds that mitigate these vulnerabilities are not available.
      This advisory is posted at
      Affected Products
      The service policy bypass vulnerability affects all versions of the
      Cisco IOS Software for the CSG2 prior to the first fixed release, as
      indicated in the "Software Versions and Fixes" section of this advisory.
      The two denial of service vulnerabilities only affect Cisco IOS Software
      Release 12.4(24)MD1 on the Cisco CSG2. No other Cisco IOS Software
      releases are affected.
      Vulnerable Products
      To determine the version of Cisco IOS Software that is running on the
      Cisco CSG2, issue the "show module" command from Cisco IOS Software on
      the switch on which the Cisco CSG2 module is installed to identify what
      modules and sub-modules are installed on the system.
      Cisco CSG2 runs on the Cisco Service and Application Module for IP
      (SAMI) card, and is identified in the following example in slot 2 via
      the WS-SVC-SAMI-BB-K9 identification:
          C7600#show module
          Mod Ports Card Type                              Model              Serial No.
          --- ----- -------------------------------------- ------------------ -----------
            1    2  Supervisor Engine 720 (Active)         WS-SUP720-3BXL     JAF1226ARQS
            2    1  SAMI Module (csgk9)                    WS-SVC-SAMI-BB-K9  SAD113906P1
            4   48  CEF720 48 port 10/100/1000mb Ethernet  WS-X6748-GE-TX     SAL1127T6XY
          Mod MAC addresses                       Hw    Fw           Sw           Status
          --- ---------------------------------- ------ ------------ ------------ -------
            1  001e.be6e.a018 to 001e.be6e.a01b   5.6   8.5(2)       12.2(33)SRC5 Ok
            2  001d.45f8.f3dc to 001d.45f8.f3e3   2.1   8.7(0.22)FW1 12.4(2010040 Ok
            4  001c.587a.ef20 to 001c.587a.ef4f   2.6   12.2(14r)S5  12.2(33)SRC5 Ok
          Mod  Sub-Module                  Model              Serial       Hw     Status
          ---- --------------------------- ------------------ ----------- ------- -------
            1  Policy Feature Card 3       WS-F6K-PFC3BXL     JAF1226BNQM  1.8    Ok
            1  MSFC3 Daughterboard         WS-SUP720          JAF1226BNMC  3.1    Ok
            2  SAMI Daughterboard 1        SAMI-DC-BB         SAD114400L9  1.1    Other
            2  SAMI Daughterboard 2        SAMI-DC-BB         SAD114207FU  1.1    Other
            4  Centralized Forwarding Card WS-F6700-CFC       SAL1029VGFK  2.0    Ok
          Mod  Online Diag Status
          ---- -------------------
            1  Pass
            2  Pass
            4  Pass
      After locating the correct slot, issue the "session slot <module number>
      processor <3-9>" command to open a console connection to the respective
      Cisco CSG2. Once connected to the Cisco CSG2, perform the "show version"
      The following example shows that the Cisco CSG2 is running software
      Release 12.4(24)MD1:
          CSG2#show version
          Cisco IOS Software, SAMI Software (SAMI-CSGK9-M), Version 12.4(24)MD1, RELEASE SOFTWARE (fc2)
          Technical Support: http://www.cisco.com/techsupport
          Copyright (c) 1986-2010 by Cisco Systems, Inc.
          Compiled Wed 07-Apr-10 09:50 by prod_rel_team
          --- output truncated ---
      Products Confirmed Not Vulnerable
      The Cisco Content Services Gateway - 1st Generation (CSG) is not
      affected by these vulnerabilities.
      No other Cisco products are currently known to be affected by these
      The Cisco Content Services Gateway - Second Generation (CSG2) provides
      intelligent network capabilities such as flexible policy management
      and billing based on deep-packet inspection, as well as subscriber and
      application awareness capabilities that enable mobile operators to
      quickly and easily offer value-added, differentiated services over their
      mobile data networks.
      The service policy bypass vulnerability affects configurations that
      allow end users to first access non-accounted or billed sites. After a
      user accesses a non-accounted site, it is possible to access other sites
      that are defined by a billing service policy or to access sites that may
      be blocked by other policies by sending specially crafted HTTP packets.
      This vulnerability only affects HTTP content traffic. HTTPS and other
      traffic types are not affected.
      Both denial of service vulnerabilities require only a single content
      service to be active on the Cisco CSG2 and can be exploited via crafted
      TCP packets. A three-way handshake is not required to exploit either of
      these vulnerabilities. The vulnerabilities are triggered by TCP traffic
      that transits the Cisco CSG2.
      The service policy bypass vulnerability is documented in Cisco Bug ID
      CSCtk35917 and has been assigned CVE ID CVE-2011-0348.
      The denial of service bugs are documented in Cisco Bug ID CSCth17178 and
      Cisco Bug ID CSCth41891 and have been assigned CVE IDs CVE-2011-0349 and
      CVE-2011-0350 respectively.
      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
      Cisco has also provided a CVSS calculator to help compute the
      environmental impact for individual networks at:
      * CSCtk35917 ("Service Policy Bypass Vulnerability")
      CVSS Base Score - 6.4
          Access Vector -            Network
          Access Complexity -        Low
          Authentication -           None
          Confidentiality Impact -   Partial
          Integrity Impact -         Partial
          Availability Impact -      None
      CVSS Temporal Score - 5.3
          Exploitability -           Functional
          Remediation Level -        Official-Fix
          Report Confidence -        Confirmed
      * CSCth41891/CSCth17178 ("Crafted TCP packet causes CSG2 to restart")
      CVSS Base Score - 7.8
          Access Vector -            Network
          Access Complexity -        Low
          Authentication -           None
          Confidentiality Impact -   None
          Integrity Impact -         None
          Availability Impact -      Complete
      CVSS Temporal Score - 6.4
          Exploitability -           Functional
          Remediation Level -        Official-Fix
          Report Confidence -        Confirmed
      Successful exploitation of the service policy bypass can allow customers
      to obtain access to sites that would normally be accounted and billed
      according to the billing policy without the billing policy being
      engaged. Additionally, customers could gain access to URLs that are
      configured in the Cisco CSG2 to be explicitly denied.
      Successful exploitation of either denial of service vulnerability could
      result in the Cisco CSG2 reloading or potentially hanging. Due to Cisco
      Bug ID CSCtg50821, the Cisco CSG2 may not automatically recover and
      may require a manual reload of the SAMI card by issuing the "hw-module
      module <x> reset" CLI command from the switch.
      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 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  |                                                  |
      | 12.x-Based |               First Fixed Release                |
      |  Releases  |                                                  |
      | 12.0 -     | 12.0 through 12.3 based releases are not         |
      | 12.3       | affected                                         |
      |  Affected  |               First Fixed Release                |
      | 12.4-Based |--------------------------------------------------|
      |  Releases  |       DoS        |     Service Policy Bypass     |
      |            | Vulnerabilities  |         Vulnerability         |
      |            | All 12.4(11)MD   |                               |
      |            | releases are not | All 12.4(11)MD releases are   |
      |            | affected.        | affected. Migrate to a fixed  |
      |            |                  | release.                      |
      |            | All 12.4(15)MD   |                               |
      |            | releases are not | All 12.4(15)MD releases are   |
      |            | affected.        | affected. Migrate to a fixed  |
      |            |                  | release.                      |
      |            | All 12.4(22)MD   |                               |
      | 12.4MD     | releases are not | All 12.4(22)MD releases are   |
      |            | affected.        | affected. Migrate to a fixed  |
      |            |                  | release.                      |
      |            | Releases prior   |                               |
      |            | to 12.4(24)MD1   | All 12.4(24)MD releases prior |
      |            | are not          | to 12.4(24)MD3 are affected.  |
      |            | affected.        |                               |
      |            |                  | First fixed in 12.4(24)MD3    |
      |            | First fixed in   |                               |
      |            | 12.4(24)MD2      |                               |
      |            |                  | All 12.4(22)MDA releases      |
      |            |                  | prior to 12.4(22)MDA5 are     |
      |            |                  | affected. First fixed in 12.4 |
      |            | No releases      | (22)MDA5                      |
      | 12.4MDA    | affected.        |                               |
      |            |                  | All 12.4(24)MDA releases      |
      |            |                  | prior to 12.4(24)MDA3 are     |
      |            |                  | affected. First fixed in 12.4 |
      |            |                  | (24)MDA3                      |
      |  Affected  |                                                  |
      | 15.X-Based |               First Fixed Release                |
      |  Releases  |                                                  |
      | 15.0 -     | 15.0 through 15.1 based releases are not         |
      | 15.1       | affected                                         |
      Cisco IOS Software for the CSG2 is located on Cisco Software Download
      center at the following location: Cisco Interfaces and Modules --> Cisco
      Services Modules --> Cisco Service Application Module for IP.
      There are no workarounds for these vulnerabilities.
      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
      or as otherwise set forth at Cisco.com Downloads at
      Do not contact psirt at cisco dot com or security-alert at cisco dot com for 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 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
      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
      for additional TAC contact information, including localized telephone
      numbers, and instructions and e-mail addresses for use in various
      Exploitation and Public Announcements
      The Cisco PSIRT is aware of public announcements of the service billing
      bypass vulnerability on some external blog sites. However the Cisco
      PSIRT is not aware of any malicious use of the vulnerabilities described
      in this advisory.
      These vulnerabilities were found by both internal testing and when
      handling customer support calls.
      Status of this Notice: FINAL
      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.
      This advisory is posted on Cisco's worldwide website at:
      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 1.0  | 2011-January-26  | 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
      This includes instructions for press inquiries regarding
      Cisco security notices. All Cisco security advisories are available at
      Copyright 2010-2011 Cisco Systems, Inc. All rights reserved.
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