Cisco Security Advisory: Multiple Vulnerabilities in Cisco Secure Access Control Server

From: Cisco Systems Product Security Incident Response Team (psirt_at_cisco.com)
Date: 08/25/04

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    Cisco Security Advisory: Multiple Vulnerabilities in Cisco Secure
    Access Control Server

    Revision 1.1

    Last Updated 2004 August 25 1630 UTC (GMT)

    For Public Release 2004 August 25 1600 UTC (GMT)

    - -----------------------------------------------------------------------

    Contents
    ========

        Summary
        Affected Products
        Details
        Impact
        Software Versions and Fixes
        Obtaining Fixed Software
        Workarounds
        Exploitation and Public Announcements
        Status of This Notice: FINAL
        Distribution
        Revision History
        Cisco Security Procedures

    - -----------------------------------------------------------------------

    Summary
    =======

    Cisco Secure Access Control Server for Windows (ACS Windows) and Cisco
    Secure Access Control Server Solution Engine (ACS Solution Engine)
    provide authentication, authorization, and accounting (AAA) services to
    network devices such as a network access server, Cisco PIX and a
    router. This advisory documents multiple Denial of Service (DoS) and
    authentication related vulnerabilities for the ACS Windows and the ACS
    Solution Engine servers.

    The vulnerabilities are documented as these Cisco bug IDs:

      * CSCeb60017
      * CSCec66913
      * CSCec90317
      * CSCed81716
      * CSCef05950

    This advisory will be posted at
    http://www.cisco.com/warp/public/707/cisco-sa-20040825-acs.shtml.

    Affected Products
    =================

    Vulnerable Products

      * Versions 3.2(3) and earlier are vulnerable to CSCef05950 and
        CSCed81716.
      * Version 3.2(2) build 15 is vulnerable to CSCeb60017.
      * Version 3.2 is vulnerable to CSCec90317 and CSCec66913.
      * CSCed81716 is only applicable to the ACS Solution Engine.

    Successfully authenticate to your ACS box to determine your software
    revision. After you perform the authentication, the first screen
    displays the current ACS version in this format-CiscoSecure ACS Release
    3.2(3) Build 11.

    ACS versions may also be displayed as 003.002(003.011), where "011" is
    the build number referenced on the ACS graphical user interface (GUI).

    Products Confirmed Not Vulnerable

    Cisco Secure ACS for UNIX is not affected by these vulnerabilities. No
    other Cisco products are currently known to be affected by these
    vulnerabilities.

    Details
    =======

    The Cisco Secure ACS products provide a centralized identity networking
    solution and simplified user management experience across all Cisco
    devices and security management applications. The products help to
    ensure enforcement of assigned policies-they allow network
    administrators to control who can log into the network, per user
    privileges in the network, security auditing and billing information,
    and command level access controls.

      * CSCeb60017 and CSCec66913 -- Cisco Secure ACS provides a Web-based
        management interface, termed CSAdmin, which listens on TCP port
        2002. When flooded with TCP connections the ACS Windows and ACS
        Solution Engine stops responding to any new TCP connections
        destined for port 2002. Additionally, services on the ACS that
        process authentication related requests may become unstable and
        stop responding, which hampers the ability for ACS to process any
        authentication related requests. A reboot of the device is
        required to restore these services.

      * CSCec90317 -- Cisco Secure ACS, when configured for Light
        Extensible Authentication Protocol (LEAP) RADIUS Proxy, forwards
        LEAP authentication requests to a secondary RADIUS server. The ACS
        device with LEAP RADIUS proxy configured may crash when LEAP
        authentication requests are being processed. A reboot is required
        to bring the device back to an operational state.

      * CSCed81716 -- Cisco Secure ACS can communicate with external
        databases and authenticate users against those databases. One of
        the external databases that ACS supports is Novell Directory
        Services (NDS). If an anonymous bind in NDS is allowed, and if the
        ACS Solution Engine is authenticating NDS users with NDS as the
        external database and not Generic LDAP, then users are able to
        authenticate with blank passwords against that NDS database.
        However, wrong passwords and incorrect usernames are properly
        rejected.

      * CSCef05950 -- Once a user successfully authenticates to the ACS
        GUI on TCP port 2002, a separate TCP connection is created between
        the browser and ACS administration Web service, with a random
        destination port. If an attacker spoofs the IP address of the user
        computer, and accesses the ACS GUI on this random port, then the
        attacker may be able to connect to the ACS GUI, bypassing
        authentication. Authentication to the ACS server may also be
        bypassed if the attacker is behind the same PAT device as that of
        the ACS user and accesses the ACS GUI on this random port.

    Impact
    ======

      * CSCeb60017, CSCec66913, and CSCec90317 -- These vulnerabilities
        may cause a crash impacting the availability of services on the
        ACS devices. Until the device is rebooted a DoS is the result.

      * CSCed81716 -- This vulnerability may allow unauthorized users to
        access AAA clients without an effective password (using blank
        passwords) if the bind to the NDS database is anonymous.

      * CSCef05950 -- This vulnerability may allow unauthenticated users
        to gain access to the ACS Administration GUI.

    Software Versions and Fixes
    ===========================

    +----------------------------------------+
    | DDTs Bug | Fixed Versions | Platform |
    | ID | | |
    |------------+----------------+----------|
    | CSCeb60017 | | ACS |
    | | 003.002 | Windows |
    | | (002.020) or | and ACS |
    | | later | Solution |
    | | | Engine |
    |------------+----------------+----------|
    | CSCec66913 | | ACS |
    | | 003.002 | Windows |
    | | (002.020) or | and ACS |
    | | later | Solution |
    | | | Engine |
    |------------+----------------+----------|
    | CSCec90317 | | ACS |
    | | 003.002 | Windows |
    | | (002.005) or | and ACS |
    | | later | Solution |
    | | | Engine |
    |------------+----------------+----------|
    | CSCed81716 | | ACS |
    | | 003.002 | Solution |
    | | (003.011) or | Engine |
    | | later | only |
    | | | |
    |------------+----------------+----------|
    | | There are | |
    | | patches | |
    | | available to | |
    | | address this | |
    | CSCef05950 | vulnerability. | ACS |
    | | See the | Windows |
    | | Customers with | and ACS |
    | | Service | Solution |
    | | Contracts | Engine |
    | | section below | |
    | | for details on | |
    | | the location | |
    | | of these | |
    | | patches. | |
    +----------------------------------------+

    Upgrade procedures can be found as indicated:

      * ACS Windows 3.3:
    http://www.cisco.com/en/US/products/sw/secursw/ps2086/prod_installation_guide09186a0080238b18.html#wp998991
      * ACS Windows 3.2:
    http://www.cisco.com/en/US/products/sw/secursw/ps2086/prod_installation_guide09186a0080184928.html#wp9472
      * ACS Solution Engine:
    http://www.cisco.com/en/US/products/sw/secursw/ps5338/products_user_guide_chapter09186a0080204d45.html#wp911224

    Obtaining Fixed 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 Cisco Product Upgrade Tool at:
    http://www.cisco.com/upgrade.

    Alternatively, Cisco Technical Assistance Center (TAC) can be
    contacted to get code upgrades for CSCeb60017, CSCec66913, CSCec90317,
    and CSCed81716.

    TAC contacts are:

      * +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

    To address CSCef05950, download the patch for your respective versions
    from:

    Public Location:

    ACS Windows:
    http://www.cisco.com/pcgi-bin/tablebuild.pl/cs-acs-win

    Registered Users:

    ACS Windows:
    http://www.cisco.com/pcgi-bin/tablebuild.pl/cs-acs-win?psrtdcat20e2

    ACS Solution Engine:
    http://www.cisco.com/pcgi-bin/tablebuild.pl/acs-soleng-3des?psrtdcat20e2

    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 assistance with the upgrade,
    which should be free of charge.

    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

    Please 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.

    Please do not contact either "psirt@cisco.com" or
    "security-alert@cisco.com" for software upgrades.

    Workarounds
    ===========

      * Configure an IP address filter on ACS Windows and ACS Solution
        Engine to limit the exposure of these vulnerabilities. From within
        the ACS GUI, browse to Administration Control > Access Policy to
        limit access to only the machines that need to administer the ACS
        remotely.
      * Apply access control lists (ACLs) on routers, switches and
        firewalls that filter traffic to the ACS so that traffic is only
        allowed from stations that need to remotely administer the box.
        Refer to http://www.cisco.com/warp/public/707/tacl.html for
        examples on how to apply ACLs on Cisco routers.
      * As a best practice, use HTTPS to limit access to the Cisco ACS GUI.
        Issues detailed in CSCef05950 still exist when you use HTTP
        instead of HTTPS to access the Cisco ACS GUI.

    Refer to
    http://www.cisco.com/univercd/cc/td/doc/product/access/acs_soft/csacs4nt/acs32/user02/a.htm#wp89030
    for information on how to set up an access policy on the Cisco ACS.

    Exploitation and Public Announcements
    =====================================

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

    Status of This Notice: FINAL
    ============================

    THIS ADVISORY IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY
    KIND OF GUARANTEE OR WARRANTY. YOUR USE OF THE INFORMATION ON THE
    ADVISORY OR MATERIALS LINKED FROM THE ADVISORY IS AT YOUR OWN RISK.
    CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS NOTICE AT ANY TIME.

    Distribution
    ============

    This advisory will be posted on Cisco's worldwide website at
    http://www.cisco.com/warp/public/707/cisco-sa-20040825-acs.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 (includes CERT/CC)
      * bugtraq@securityfocus.com
      * vulnwatch@vulnwatch.org
      * cisco@spot.colorado.edu
      * cisco-nsp@puck.nether.net
      * full-disclosure@lists.netsys.com
      * 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
    ================

    +----------------------------------------+
    | | | Changed |
    | | | URLs in |
    | Revision | | the |
    | 1.1 | 2004-August-25 | Obtaining |
    | | | Fixed |
    | | | Software |
    | | | section. |
    |----------+----------------+------------|
    | Revision | | Initial |
    | 1.0 | 2004-August-25 | 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/warp/public/707/sec_incident_response.shtml. 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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