Summary

• A vulnerability in a proprietary device driver in the kernel of Cisco TelePresence Multipoint Control Unit (MCU) Software could allow an unauthenticated, remote attacker to execute arbitrary code or cause a denial of service (DoS) condition.
  
  The vulnerability is due to improper size validation when reassembling fragmented IPv4 or IPv6 packets. An attacker could exploit this vulnerability by sending crafted IPv4 or IPv6 fragments to a port receiving content in Passthrough content mode. An exploit could allow the attacker to overflow a buffer. If successful, the attacker could execute arbitrary code or cause a DoS condition on the affected system.
  
  Cisco has released software updates that address this vulnerability. Workarounds that address this vulnerability are not available.
  
  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170125-telepresence

Affected Products

• Vulnerable Products

  The following Cisco TelePresence MCU platforms are affected when running software version 4.3(1.68) or later configured for Passthrough content mode:
  

  • TelePresence MCU 5300 Series
  • TelePresence MCU MSE 8510
  • TelePresence MCU 4500

  Administrators can verify the current Software version by navigating to the General status page under Status > General in the web-based graphical user interface (GUI). The Content mode can be verified under Conferences > Conference "Name" > Configuration.

  Products Confirmed Not Vulnerable

  The following Cisco TelePresence MCU platforms are not affected by this vulnerability in any software release:
  

  • TelePresence MCU 4200 Series
  • TelePresence MCU MSE 8420

Workarounds

• There are no workarounds that address this vulnerability.
  
  Mitigations
  
  To prevent exploitation of this vulnerability, customers can configure TelePresence MCU Software to use Transcoded content mode instead of Passthrough content mode.
  
  Note: In Transcoded content mode, video resolution might be lower than in Passthrough content mode.

Fixed Software

• Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:
  http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html

  Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.

  When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to upgrade contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Customers Without Service Contracts

  Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC:
  http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html

  Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.

  Fixed Releases
  
  In the following table the left column lists major releases of Cisco TelePresence Software. The right column indicates whether a major release is affected by the vulnerability described in this advisory and the first release that includes the fix for this vulnerability. Customers should upgrade to an appropriate release as indicated in the following table:

  Cisco TelePresence Software Major Release	First Fixed Release
  4.2 and earlier	Not affected
  4.31	Affected; migrate to 4.5(1.89)
  4.4	Affected; migrate to 4.5(1.89)
  4.5	Affected; migrate to 4.5(1.89)

  
  ¹ Passthrough content mode was only introduced in version 4.3(1.68). TelePresence Software 4.3 releases prior to 4.3(1.68) are not affected by this vulnerability.
  
  Note: There will be no fix for the TelePresence MCU 4500 platform as that platform has reached the end-of-software maintenance milestone on July 9, 2016:
  End-of-Sale and End-of-Life Announcement for the Cisco TelePresence MCU 4500 Series
  

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

• This vulnerability was found during the resolution of a support case.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170125-telepresence

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	—	Final	2017-January-25

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