[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 Memory Leak Vulnerabilities
  • From: Cisco Systems Product Security Incident Response Team <psirt at cisco dot com>
  • Date: Wed, 28 Sep 2011 12:00:00 -0400
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      Cisco Security Advisory: Cisco Unified Communications Manager Session
      Initiation Protocol Memory Leak Vulnerability
      Advisory ID: cisco-sa-20110928-cucm
      Revision 1.0
      For Public Release 2011 September 28 1600 UTC (GMT)
      Cisco Unified Communications Manager contains a memory leak
      vulnerability that could be triggered through the processing of
      malformed Session Initiation Protocol (SIP) messages. Exploitation of
      this vulnerability could cause an interruption of voice services.
      Cisco has released free software updates for supported Cisco Unified
      Communications Manager versions to address the vulnerability. A
      workaround exists for this SIP vulnerability.
      This advisory is posted at
      Note: The September 28, 2011, Cisco IOS Software Security Advisory
      bundled publication includes ten Cisco Security Advisories. Nine of
      the advisories address vulnerabilities in Cisco IOS Software, and one
      advisory addresses a vulnerability in Cisco Unified Communications
      Manager. Each advisory lists the Cisco IOS Software releases that
      correct the vulnerability or vulnerabilities detailed in the advisory
      as well as the Cisco IOS Software releases that correct all
      vulnerabilities in the September 2011 Bundled Publication.
      Individual publication links are in "Cisco Event Response: Semiannual
      Cisco IOS Software Security Advisory Bundled Publication" at the
      following link:
      Cisco IOS Software is affected by the SIP vulnerability described in
      this advisory. A separate Cisco Security Advisory has been published
      to disclose the vulnerabilities that affect the Cisco IOS software at
      the following location:
      Affected Products
      Vulnerable Products
      The following products are affected by the vulnerability that is
      described in this advisory:
        * Cisco Unified Communications Manager 6.x
        * Cisco Unified Communications Manager 7.x
        * Cisco Unified Communications Manager 8.x
      Note: Cisco Unified Communications Manager version 6.1 reached the
      End of Software Maintenance on September 3, 2011. Customers using
      Cisco Unified Communications Manager 6.x versions, should contact
      their Cisco support team for assistance in upgrading to a supported
      version of Cisco Unified Communications Manager.
      Products Confirmed Not Vulnerable
      Cisco Unified Communications Manager version 4.x is not affected by
      this vulnerability. No other Cisco products are currently known to be
      affected by this vulnerability.
      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, VoIP gateways, and multimedia
      Memory Leak Vulnerability in SIP
      Cisco Unified Communications Manager contains a vulnerability that
      involves the processing of SIP messages. Cisco Unified Communications
      Manager may leak session control buffers (SCBs) when processing a
      malformed SIP message. Continued exploitation of the vulnerability
      may cause a critical process to fail, which could result in the
      disruption of voice services. All SIP ports (TCP ports 5060 and 5061
      and UDP ports 5060 and 5061) are affected.
      This SIP vulnerability is documented in Cisco bug ID CSCtl86047 and
      has been assigned the CVE identifier CVE-2011-2072. This vulnerability
      is fixed in Cisco Unified Communications Manager versions 8.6(1),
      8.5(1)su2, and 7.1(5b)su4. [Note: there is not a software Service Update
      for the 6.x version that contains the fix.]
      Note: This vulnerability also affects Cisco IOS Software. The
      corresponding Cisco bug ID is CSCto88686. Refer to the separate Cisco
      Security Advisory for the Cisco IOS Software for additional details.
      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:
      Cisco has also provided a CVSS calculator to help compute the
      environmental impact for individual networks at:
      * CSCtl86047
      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 vulnerability that is described in
      this advisory could allow a remote attacker to trigger a memory leak
      that could result in the interruption of voice services. Cisco
      Unified Communications Manager will restart the affected processes,
      but repeated attacks may result in a sustained denial of service
      (DoS) condition.
      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. Cisco recommends upgrading
      to a release equal to or later than the release in the "Recommended
      Releases" column of the table.
      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.
      Additionally, the Cisco IOS Software Checker is available on
      the Cisco Security Intelligence Operations (SIO) portal at
      http://tools.cisco.com/security/center/selectIOSVersion.x. It provides
      several features for checking which Security Advisories affect specified
      versions of Cisco IOS Software.
      |      Cisco Unified      | Recommended |
      |  Communication Manager  |   Release   |
      |         Version         |             |
      | 7.x                     | 7.1(5b)su4  |
      | 8.x*                    | 8.5(1)su2,  |
      |                         | 8.6(1)      |
      *The recommended releases listed in the table above are the latest
      Cisco Unified Communications Manager versions available at the
      publication of this advisory. Software updates for 6.1 and 8.0 are
      not available for CSCtl86047. Customers using these versions should
      consult their Cisco support team for assistance in upgrading to a
      supported release.
      Cisco Unified Communications Manager software can be downloaded from
      the following link:
      A workaround exists for customers who do not require SIP in their
      environment. Cisco Unified Communication Manager versions 6.1(4), 7.1
      (2) and 8.0(1) introduced the ability to disable SIP processing. SIP
      processing is enabled by default. Use the following instructions to
      disable SIP processing:
        * Step 1: Log in to the Cisco Unified CM Administration web
        * Step 2: Navigate to "System > Service Parameters" and select the
          appropriate Cisco Unified Communications Manager server and the
          Cisco CallManager service.
        * Step 3: Change the SIP Interoperability Enabled parameter to
          False and click "Save".
          Note: For a SIP processing change to take effect, the Cisco
          CallManager Service must be restarted. For information on how to
          restart the service, refer to the "Restarting the Cisco
          CallManager Service" section of the document at
          It is possible to mitigate this vulnerability by implementing
          filtering on screening devices and permitting access to TCP ports
          5060 and 5061 and UDP ports 5060 and 5061 only from networks that
          require SIP access to Cisco Unified Communications Manager
          Additional mitigations that can be deployed on Cisco devices in
          the network are available in the companion document "Cisco
          Applied Mitigation Bulletin: Identifying and Mitigating
          Exploitation of the Multiple Vulnerabilities in Cisco Voice
          Products" which is available at the following location:
      Obtaining Fixed Software
      Cisco has released free software updates that address this
      vulnerability. 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 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
      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 not aware of any public announcements or malicious
      use of the vulnerability described in this advisory.
      This vulnerability was found during internal testing and the
      troubleshooting of customer service requests.
      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-September-28 | 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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