[apops] Cisco Security Advisory: Cisco Unified Communications Manager Se

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  • Subject: [apops] Cisco Security Advisory: Cisco Unified Communications Manager Session Initiation Protocol Denial of Service Vulnerabilities
  • From: Cisco Systems Product Security Incident Response Team <psirt at cisco dot com>
  • Date: Wed, 24 Sep 2008 17:50:00 +0200
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      Cisco Security Advisory: Cisco Unified Communications Manager Session
      Initiation Protocol Denial of Service Vulnerabilities
      
      Advisory ID: cisco-sa-20080924-cucm
      
      http://www.cisco.com/warp/public/707/cisco-sa-20080924-cucm.shtml
      
      Revision 1.0
      
      For Public Release 2008 September 24 1600 UTC (GMT)
      
      - ---------------------------------------------------------------------
      
      Summary
      =======
      
      Cisco Unified Communications Manager, formerly Cisco Unified
      CallManager, contains two denial of service (DoS) vulnerabilities in
      the Session Initiation Protocol (SIP) service. An exploit of these
      vulnerabilities may cause an interruption in voice services.
      
      Cisco will release free software updates that address these
      vulnerabilities and this advisory will be updated as fixed software
      becomes available. There are no workarounds for these
      vulnerabilities.
      
      Note:  Cisco IOS software is also affected by the vulnerabilities
      described in this advisory. A companion advisory for Cisco IOS
      software is available at 
      http://www.cisco.com/warp/public/707/cisco-sa-20080924-sip.shtml
      
      This advisory is posted at 
      http://www.cisco.com/warp/public/707/cisco-sa-20080924-cucm.shtml
      
      Affected Products
      =================
      
      The vulnerabilities described in this document apply to the Cisco
      Unified Communications Manager.
      
      Vulnerable Products
      +------------------
      
      The following Cisco Unified Communications Manager versions are
      affected:
      
        * Cisco Unified CallManager 4.1 versions prior to 4.1.3SR8
        * Cisco Unified CallManager 4.2 versions prior to 4.2(3)SR4b
        * Cisco Unified CallManager 4.3 versions prior to 4.3(2)SR1a
        * Cisco Unified Communications Manager 5.x versions prior to 5.1
          (3d)
        * Cisco Unified Communications Manager 6.x versions prior to 6.1(2)
          su1
      
      Administrators of systems running Cisco Unified CallManager version
      4.x can determine the software version by navigating to Help > About
      Cisco Unified CallManager and selecting the Details button via the
      Cisco Unified Communications Manager Administration interface.
      
      Administrators of systems that are running Cisco Unified
      Communications Manager versions 5.x and 6.x can determine the
      software version by viewing the main page of the Cisco Unified
      Communications Manager Administration interface. The software version
      can also be determined by running the command show version active via
      the command line interface.
      
      In Cisco Unified CallManager version 4.x, the use of SIP as a call
      signaling protocol is not enabled by default, and for the Cisco
      Unified CallManager server to start listening for SIP messages on TCP
      and UDP ports 5060 and 5061 a SIP trunk needs to be configured.
      
      In Cisco Unified Communications Manager versions 5.x and later, the
      use of SIP as a call signaling protocol is enabled by default in
      Cisco Unified Communications Manager and cannot be disabled.
      
      Cisco IOS software is also affected by these vulnerabilities,
      although they are tracked by different Cisco bug IDs. A companion
      security advisory for Cisco IOS software is available at 
      http://www.cisco.com/warp/public/707/cisco-sa-20080924-sip.shtml
      
      Products Confirmed Not Vulnerable
      +--------------------------------
      
      With the exception of Cisco IOS software, no other Cisco products are
      currently known to be vulnerable to the issues described in this
      advisory.
      
      Cisco Unified Communications Manager version 7.x is not affected by
      these vulnerabilities.
      
      Cisco Unified CallManager version 4.x is not affected by these
      vulnerabilities if it does not have any SIP trunks configured.
      
      Details
      =======
      
      Cisco Unified Communications Manager is the call processing component
      of the Cisco IP Telephony solution that extends enterprise telephony
      features and functions to packet telephony network devices, such as
      IP phones, media processing devices, voice-over-IP gateways, and
      multimedia applications.
      
      SIP is a popular signaling protocol that is used to manage voice and
      video calls across IP networks such as the Internet. SIP is
      responsible for handling all aspects of call setup and termination.
      Voice and video are the most popular types of sessions that SIP
      handles, but the protocol is flexible to accommodate for other
      applications that require call setup and termination. SIP call
      signaling can use UDP (port 5060), TCP (port 5060), or TLS (TCP port
      5061) as the underlying transport protocol.
      
      Two DoS vulnerabilities exist in the SIP implementation of the Cisco
      Unified Communications Manager. These vulnerabilities can be
      triggered while processing specific and valid SIP messages and can
      lead to a reload of the main Cisco Unified Communications Manager
      process. Version 4.x of Cisco Unified CallManager do not have SIP
      enabled by default unless a SIP trunk is configured. Versions 5.x and
      later of the Cisco Unified Communications Manager have SIP is enabled
      by default and cannot be disabled.
      
      The vulnerabilities are being tracked by the following Cisco bug IDs:
      
        * CSCsu38644, assigned CVE ID CVE-2008-3800
        * CSCsm46064, assigned CVE ID CVE-2008-3801
      
      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 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
      
      
      CSCsu38644 - Valid SIP message can cause CCM process to crash
      
      CVSS Base Score - 7.1
      
              Access Vector          - Network
              Access Complexity      - Medium
              Authentication         - None
              Confidentiality Impact - None
              Integrity Impact       - None
              Availability Impact    - Complete
      
      CVSS Temporal Score - 5.9
      
              Exploitability          - Functional
              Remediation Level       - Official-Fix
              Report Confidence       - Confirmed
      
      
      CSCsm46064 - Problem when CUCM sends out SIP message with valid header
      
      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
      
      
      Impact
      ======
      
      Successful exploitation of the vulnerabilities described in this
      advisory may result in a reload of the Cisco Unified Communications
      Manager process, which could result in the interruption of voice
      services.
      
      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.
      
      Cisco Unified CallManager version 4.1(3)SR8 contains fixes for all
      vulnerabilities affecting Cisco Unified CallManager version 4.1
      listed in this advisory, and is scheduled to be released in early
      October 2008.
      
      Cisco Unified CallManager version 4.2(3)SR4b contains fixes for all
      vulnerabilities affecting Cisco Unified Communications Manager
      version 4.2.x listed in this advisory, and is scheduled to be
      released in early November 2008.
      
      Cisco Unified CallManager version 4.3(2)SR1a contains fixes for all
      vulnerabilities affecting Cisco Unified Communications Manager
      version 4.3.x listed in this advisory, and is scheduled to be
      released in early October 2008.
      
      Cisco Unified Communications Manager version 5.1(3d) contains fixes
      for all vulnerabilities affecting Cisco Unified Communications
      Manager version 5.x listed in this advisory, and is scheduled to be
      released in mid October 2008.
      
      Cisco Unified Communications Manager version 6.1(2)SU1 contains fixes
      for all vulnerabilities affecting Cisco Unified Communications
      Manager version 6.x listed in this advisory, and is scheduled to be
      released in mid October 2008.
      
      Downloading Cisco Unified Communications Manager Software
      +--------------------------------------------------------
      
      To download Cisco Unified Communications Manager Software go to the
      Voice Software Downloads section of the Software Center on cisco.com
      at 
      http://tools.cisco.com/support/downloads/go/Redirect.x?mdfid=278875240
      then navigate to IP Telephony > Call Control > Cisco Unified 
      Communications Manager (CallManager) and select the appropriate 
      version of Cisco Unified Communications Manager.
      
      Workarounds
      ===========
      
      There are no workarounds for these vulnerabilities.
      
      It is possible to mitigate the vulnerabilities by implementing
      filtering on screening devices. Permit TCP/UDP access to ports 5060
      and 5061 from only networks that need SIP access to Cisco Unified
      Communications Manager servers.
      
      If the Cisco Unified Communications Manager does not need to provide
      SIP services, the ports on which the Cisco Unified Communications
      Manager listens for SIP messages can be moved to non-standard ports.
      To change the ports from their default values, log into the Cisco
      Unified CallManager Administration web interface, go to System >
      Cisco Unified CM, locate the appropriate Cisco Unified Communications
      Manager, change the fields SIP Phone Port and SIP Phone Secure Port
      to a non-standard port, then click Save. SIP Phone Port, by default
      5060, refers to the TCP and UDP ports where the Cisco Unified
      Communications Manager listens for normal SIP messages, and SIP Phone
      Secure Port, by default 5061, refers to the TCP and UDP ports where
      the Cisco Unified Communications Manager listens for SIP over TLS
      messages. For additional information about this procedure, refer to
      the "Updating a Cisco Unified Communications Manager" section of the
      "Cisco Unified Communications Manager Administration Guide" at 
      http://www.cisco.com/en/US/docs/voice_ip_comm/cucmbe/admin/7_0_1/ccmcfg/b02ccm.html#wp1057513.
      
      Note:  For a change of the SIP ports to take effect, the Cisco
      CallManager Service needs to be restarted. For information on how to
      accomplish this, refer to "Restarting the Cisco CallManager Service"
      at 
      http://www.cisco.com/en/US/docs/voice_ip_comm/cucmbe/admin/7_0_1/ccmcfg/b03dpi.html#wp1075124
      
      Additional mitigations that can be deployed on Cisco devices within
      the network are available in the Cisco Applied Mitigation Bulletin
      companion document for this advisory, which is available at the
      following link: 
      http://www.cisco.com/warp/public/707/cisco-amb-20080924-sip.shtml
      
      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/products/prod_warranties_item09186a008088e31f.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/warp/public/687/Directory/DirTAC.shtml
      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.
      
      These vulnerabilities were discovered by Cisco internal testing and
      during handling of customer service requests.
      
      Status of this Notice: INTERIM
      ==============================
      
      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. CISCO EXPECTS TO UPDATE THIS DOCUMENT AS NEW
      INFORMATION BECOMES AVAILABLE.
      
      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-20080924-cucm.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      | 2008-September-24 | 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
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