Cisco Security Advisory

Denial of Service Vulnerability in Cisco TelePresence Codecs

Advisory ID: cisco-sa-20110831-tandberg

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110831-tandberg

Revision 1.1

Last Updated  2011 September 1 21:00  UTC (GMT)

For Public Release 2011 August 31 16:00  UTC (GMT)


Summary

Cisco TelePresence C Series Endpoints, E/EX Personal Video units, and MXP Series Codecs that are running software versions prior to TC4.0.0 or F9.1 contain a vulnerability that could allow an attacker to cause a denial of service.

Cisco has released free software updates that address this vulnerability.

This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110831-tandberg.

Affected Products

Vulnerable Products

This vulnerability affects Cisco TelePresence MXP Series systems that are running software on the following codecs:

  • 6000MXP
  • 3000MXP
  • 2000MXP
  • 1700MXP
  • 1000MXP
  • 990MXP
  • 880MXP
  • 770MXP
  • 550MXP
  • Edge 75MXP
  • Edge 85MXP
  • Edge 95MXP

This vulnerability also affects Cisco TelePresence C Series Endpoints and E/EX Personal Video units that are running software on the following codecs:

  • C20
  • C40
  • C60
  • C90
  • EX60
  • EX90

Users can determine the software version of a Cisco TelePresence unit by entering the IP address of the codec in a web browser, authenticating (if the device is configured for authentication), and then selecting the system info menu option. The version number will follow the Software Version text in the System Info window.

Alternatively, users can determine the software version by issuing the xStatus SystemUnit command from a device's application programmer interface. The software version that is running on the codec is displayed following the SystemUnit Software Version text. The following example displays xStatus SystemUnit output from a system that is running software version TC4.0:

xStatus SystemUnit
*s SystemUnit ProductType: "Cisco TelePresence Codec"
*s SystemUnit ProductId: "Cisco TelePresence Codec C90"
*s SystemUnit ProductPlatform: "C90"
*s SystemUnit Uptime: 597095
*s SystemUnit Software Application: "Endpoint"
*s SystemUnit Software Version: "TC4.0"
*s SystemUnit Software Name: "s52000"
*s SystemUnit Software ReleaseDate: "2010-11-01"
*s SystemUnit Software MaxVideoCalls: 3
*s SystemUnit Software MaxAudioCalls: 4
*s SystemUnit Software ReleaseKey: "true"
*s SystemUnit Software OptionKeys NaturalPresenter: "true"
*s SystemUnit Software OptionKeys MultiSite: "true"
*s SystemUnit Software OptionKeys PremiumResolution: "true"
*s SystemUnit Hardware Module SerialNumber: "B1AD25A00003"
*s SystemUnit Hardware Module Identifier: "0"
*s SystemUnit Hardware MainBoard SerialNumber: "PH0497201"
*s SystemUnit Hardware MainBoard Identifier: "101401-3 [04]"
*s SystemUnit Hardware VideoBoard SerialNumber: "PH0497874"
*s SystemUnit Hardware VideoBoard Identifier: "101560-1 [02]"
*s SystemUnit Hardware AudioBoard SerialNumber: "N/A"
*s SystemUnit Hardware AudioBoard Identifier: ""
*s SystemUnit Hardware BootSoftware: "U-Boot 2009.03-65"
*s SystemUnit State System: Initialized
*s SystemUnit State MaxNumberOfCalls: 3
*s SystemUnit State MaxNumberOfActiveCalls: 3
*s SystemUnit State NumberOfActiveCalls: 1
*s SystemUnit State NumberOfSuspendedCalls: 0
*s SystemUnit State NumberOfInProgressCalls: 0
*s SystemUnit State Subsystem Application: Initialized
*s SystemUnit ContactInfo: "helpdesk@company.com"
** end

Products Confirmed Not Vulnerable

The Cisco TelePresence MX200 Codec is not affected by this vulnerability. No other Cisco products are currently known to be affected by this vulnerability.

Details

Affected devices are part systems that provide Cisco TelePresence Endpoints for immersive environments, conference rooms, individual desktops, and home offices. The Cisco TelePresence MXP and C Series Endpoints are typically deployed as Multipurpose Room Systems, and the Cisco TelePresence E/EX Personal Video units are desktop devices.

Software versions prior to TC 4.0.0 or F9.1 contain a vulnerability that could cause a crash of the device and result in a denial of service condition. This vulnerability is triggered by a crafted Session Initiation Protocol (SIP) packet that is sent to an affected device on port 5060 or 5061.

Software for the Cisco TelePresence units is available for download at: http://www.tandberg.com/support/video-conferencing-software-download.jsp?t=2 leavingcisco.com

This vulnerability is documented in Cisco bug ID CSCtq46500 ( registered customers only) and has been assigned CVE ID CVE-2011-2577.

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.

Specifically crafted SIP packet may crash the device

Calculate the environmental score of CSCtq46500

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

Impact

Successful exploitation of this vulnerability could result in a system crash that may lead to a denial of service 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.

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.


Workarounds

There are no workarounds available that mitigate this vulnerability. However, there is an Applied Mitigations Bulletin available at http://tools.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20110831-tandberg that describes how to filter SIP packets sent to the device.

Obtaining Fixed Software

Cisco has released free software updates that addresses 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 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@cisco.com or security-alert@cisco.com for software upgrades.

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@cisco.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 reported to Cisco by David Klein of Sense of Security.

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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20110831-tandberg

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
  • bugtraq@securityfocus.com
  • vulnwatch@vulnwatch.org
  • cisco@spot.colorado.edu
  • cisco-nsp@puck.nether.net
  • full-disclosure@lists.grok.org.uk
  • 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

Revision 1.1

2011-Sep-01

Clarified affected codecs in Vulnerable Products section and included Cisco TelePresence MX200 Codec in Products Confirmed Not Vulnerable section.

Revision 1.0

2011-Aug-31

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 http://www.cisco.com/web/about/security/psirt/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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