Summary

• A failure in the final QA validation step of the automated software build system for the Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) software inadvertently allowed a set of sample, dormant exploit code used internally by Cisco in validation scripts to be included in shipping software images. This includes an exploit for the Dirty CoW vulnerability (CVE-2016-5195). The purpose of this QA validation step is to make sure the Cisco product contains the required fixes for this vulnerability.
  
  The presence of the sample, dormant exploit code does not represent nor allow an exploitable vulnerability on the product, nor does it present a risk to the product itself as all of the required patches for this vulnerability have been integrated into all shipping software images.
  
  The affected software images have proactively been removed from the Cisco Software Center. Bug ID CSCvn17278 has been opened to track this issue.

  Customers that still require access to the affected software images and have a valid cisco.com account will need to open a case with the Cisco TAC and submit a request for Special File access in order to download the software images.

  Cisco has released software updates that address this issue. There are no workarounds that address this issue.

  This advisory is available at the following link:
  https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-vcsd

Affected Products

• Vulnerable Products

  This issue affects Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) image versions X8.9 through X8.11.3. Versions prior to X8.9 are not affected by this issue.

  Products Confirmed Not Vulnerable

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.

Workarounds

• There are no workarounds that address this issue.

Fixed Software

• Fixed Releases

  This issue is fixed in Cisco TelePresence Video Communication Server and Expressway release version x8.11.4.

  The software can be downloaded from the Software Center on Cisco.com by clicking Browse all and navigating to the following locations:

  Cisco TelePresence Video Communication Server and Expressway

  1. Navigate to Unified Communications > Communication Gateways > Expressway Series > Expressway > TelePresence Software- X8.11.4.

  2. From the left panel click X8.11.4 under Latest Release.

  3. Choose the correct X8.11.4 file for your deployment type.

   

  Cisco TelePresence Video Communication Server Model

  1. Navigate to Unified Communications > Communication Gateways > Video Gateways > TelePresence Video Communication Server (VCS) > TelePresenceVideo Communication Server Model > TelePresence Software- X8.11.4
  

  2. From the left panel click X8.11.4 under Latest Release.

  3. Choose the correct X8.11.4 file for your deployment type.

   

Exploitation and Public Announcements

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

Source

• This issue was found during internal security testing.

URL

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-vcsd

Revision History

• Version	Description	Section	Status	Date
  1.2	Added Fixed Software release information	Fixed Software	Final	2018-November-20
  1.1	Added information about Special File access.	Summary	Final	2018-November-08
  1.0	Initial public release.	—	Final	2018-November-07

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