Cisco Security Advisory

Cisco TelePresence Video Communication Server SIP Denial of Service Vulnerability

Advisory ID: cisco-sa-20140122-vcs

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20140122-vcs

Revision 1.0

For Public Release 2014 January 22 16:00  UTC (GMT)


Summary

Cisco TelePresence Video Communication Server (VCS) contains a vulnerability that could allow an unauthenticated, remote attacker to trigger the failure of several critical processes which may cause active call to be dropped and prevent users from making new calls until the affected system is reloaded.

Cisco has released free software updates that address this vulnerability. Workarounds that mitigate this vulnerability are not available. This advisory is available at the following link:
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20140122-vcs

Affected Products

Vulnerable Products

This vulnerability affects Cisco TelePresence VCS Control, Cisco TelePresence VCS Expressway, and Cisco TelePresence VCS Starter Pack Expressway running Cisco TelePresence VCS Software prior to X8.1.
Cisco TelePresence VCS hardware and virtual appliances are both affected by this vulnerability.

Products Confirmed Not Vulnerable

No other Cisco products are currently known to be affected by this vulnerability.

Details

Cisco TelePresence VCS extends the benefits of face-to-face video collaboration across networks and organizations by supporting any-to-any video and telepresence communications.

A vulnerability in the Session Initiation Protocol (SIP) module of Cisco TelePresence Video Communication Server (VCS) could allow an unauthenticated, remote attacker to trigger the failure of several critical processes, which may cause the termination of active calls. New calls will also not be established until the affected system is restored.

The vulnerability is due to improper handling of crafted Session Description Protocol (SDP) messages. An attacker could exploit this vulnerability by sending a crafted SDP message to the affected system. An exploit could allow the attacker to trigger the failure of several critical processes, which may cause the affected system to not function properly; active calls will be terminated and new calls will not be possible until the affected system is restored. A reload is needed to restore correct functionality.

This vulnerability can be triggered by SDP messages sent via UDP or TCP. Deployment using Transport Layer Security (TLS) will also be affected.
The default port for UDP and TCP deployments is UDP port 5060 and TCP port 5060. The default port for TLS deployment is TCP port 5061.

This vulnerability is documented in Cisco bug ID CSCue97632 (registered customers only) and has been assigned Common Vulnerability and Exposures (CVE) ID CVE-2014-0662.

Vulnerability Scoring Details

Cisco has scored the vulnerability in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this security advisory is in accordance with CVSS version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability severity and helps organizations determine the urgency and priority of a response.

Cisco has provided a base and temporal score. Customers can also compute environmental scores that help determine the impact of the vulnerability in their own networks.

Cisco has provided additional information regarding CVSS at the following link:

http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to compute the environmental impact for individual networks at the following link:

http://intellishield.cisco.com/security/alertmanager/cvss



CSCue97632 - Cisco TelePresence Video Communication Server SDP Denial of Service Vulnerability

Calculate the environmental score of CSCue97632

CVSS Base Score - 7.1

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Medium

None

None

None

Complete

CVSS Temporal Score - 5.9

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed


Impact

Successful exploitation of the vulnerability may cause the failure of several internal critical processes and the affected system will not be able to function properly; active calls will be terminated and new calls will not be possible until the affected system is restored. A reload is needed to restore correct functionality.

Software Versions and Fixes

When considering software upgrades, customers are advised to consult the Cisco Security Advisories, Responses, and Notices archive at http://www.cisco.com/go/psirt and review subsequent advisories to determine exposure and a complete upgrade solution.

In all cases, customers should ensure that the devices to be upgraded 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.

This vulnerability is resolved in Cisco TelePresence VCS Software X8.1 and later.

Workarounds

There are no workarounds that mitigate this vulnerability.

Additional mitigations that can be deployed on Cisco devices within the network are available in the Cisco Applied Intelligence companion document for this Advisory: http://tools.cisco.com/security/center/viewAMBAlert.x?alertId=32409

Obtaining Fixed Software

Cisco has released free software updates that address the vulnerability described in this advisory. Prior to deploying software, customers are advised to consult their maintenance providers or check the software for feature set compatibility and known issues that are specific to their environments.

Customers may only install and expect support for feature sets they have purchased. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html.

Customers with Service Contracts

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, upgrades should be obtained through the Software Navigator on Cisco.com at http://www.cisco.com/cisco/software/navigator.html.

Customers Using Third-Party Support Organizations

Customers with Cisco products that 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 organization for assistance with the appropriate course of action.

The effectiveness of any workaround or fix depends on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Because of the variety of affected products and releases, customers should consult their service providers or support organizations to ensure that any applied workaround or fix is the most appropriate in the intended network before it is deployed.

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 Technical Assistance Center (TAC):

  • +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 the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade. Customers without service contracts should request free upgrades through the TAC.

Refer to Cisco Worldwide Contacts at http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, instructions, and e-mail addresses for support in various languages.

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.

This vulnerability was found during internal testing.

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 Security Intelligence Operations at the following link:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20140122-vcs

Additionally, a text version of this advisory is clear signed with the Cisco PSIRT PGP key and circulated among the following e-mail addresses:

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

Future updates of this advisory, if any, will reside on Cisco.com but may not be announced on mailing lists. Users can monitor this advisory's URL for any updates.


Revision History

Revision 1.0 2014-January-22 Initial public release

Cisco Security Procedures

Complete information about reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco is available on Cisco.com at http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html. This web page includes instructions for press inquiries regarding Cisco Security Advisories. All Cisco Security Advisories are available at http://www.cisco.com/go/psirt.


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