Summary

• A vulnerability in the Common Industrial Protocol (CIP) feature of Cisco IOS Software could allow an unauthenticated, remote attacker to create a denial of service (DoS) condition.
  
  The vulnerability is due to a failure to properly process an unusual, but valid, set of requests to an affected device. An attacker could exploit this vulnerability by submitting a CIP message request designed to trigger the vulnerability to an affected device. An exploit could cause the switch to stop processing traffic, requiring a restart of the device to regain functionality.
  
  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
  
  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160928-cip
  
  This advisory is part of the September 28, 2016, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 10 Cisco Security Advisories that describe 11 vulnerabilities. All the vulnerabilities have a Security Impact Rating of “High.” For a complete list of the advisories and links to them, see Cisco Event Response: September 2016 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
  

Affected Products

• The CIP feature is commonly available on Cisco Industrial Ethernet Switch products and used for industrial automation applications. The protocol was previously known as the Control and Information Protocol.

  Vulnerable Products

  This vulnerability affects Cisco devices running affected Cisco IOS Software releases only when affected devices are configured to process CIP messages. The CIP feature is disabled by default.
  
  For information about which Cisco IOS Software releases are vulnerable, see the Fixed Software section of this advisory.
  
  To determine whether the CIP feature is enabled, use the show running-config | include cip enable command and verify that it returns output. The following example shows a device running Cisco IOS Software with CIP processing enabled:
  

  router#show running-config | include cip enable
  cip enable

  
  This vulnerability can be exploited only with IPv4 packets destined to UDP port 2222 or 44818 on an affected device. TCP packets, packets transiting an affected device, or IPv6 packets cannot be used to trigger this vulnerability.
  
  

  Determining the Cisco IOS Software Release

  To determine which Cisco IOS Software release is running on a device, administrators can log in to the device, use the show version command in the command-line interface (CLI), and then refer to the system banner that appears. If the device is running Cisco IOS Software, the system banner displays text similar to Cisco Internetwork Operating System Software or Cisco IOS Software. The banner also displays the installed image name in parentheses, followed by the Cisco IOS Software release number and release name. Some Cisco devices do not support the show version command or may provide different output.

  The following example identifies a Cisco product that is running Cisco IOS Software Release 15.5(2)T1 with an installed image name of C2951-UNIVERSALK9-M:

  Router> show version 
  Cisco IOS Software, C2951 Software (C2951-UNIVERSALK9-M), Version 15.5(2)T1, RELEASE SOFTWARE (fc1)
  Technical Support: http://www.cisco.com/techsupport
  Copyright (c) 1986-2015 by Cisco Systems, Inc.
  Compiled Mon 22-Jun-15 09:32 by prod_rel_team
  .
  .
  .

  For information about the naming and numbering conventions for Cisco IOS Software releases, see White Paper: Cisco IOS and NX-OS Software Reference Guide.

  Products Confirmed Not Vulnerable

  No other Cisco products are currently known to be affected by this vulnerability.
  
  Cisco has confirmed that this vulnerability does not affect Cisco IOS XE Software, Cisco IOS XR Software, or Cisco NX-OS Software.

Workarounds

• There are no workarounds that address this vulnerability.

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 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.

  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):
  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.

  Cisco IOS Software

  To help customers determine their exposure to vulnerabilities in Cisco IOS Software, Cisco provides a tool, the Cisco IOS Software Checker, that identifies any Cisco Security Advisories that impact a specific Cisco IOS Software release and the earliest release that fixes the vulnerabilities described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified (“Combined First Fixed”).

  Customers can use this tool to perform the following tasks:

  • Initiate a search by choosing one or more releases from a drop-down menu or uploading a file from a local system for the tool to parse
  • Enter the output of the show version command for the tool to parse
  • Create a custom search by including all previously published Cisco Security Advisories, a specific advisory, or all advisories in the most recent bundled publication

  To determine whether a release is affected by any published Cisco Security Advisory, use the Cisco IOS Software Checker on Cisco.com or enter a Cisco IOS Software release—for example, 15.1(4)M2—in the following field:

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 reported to Cisco by a Cisco partner.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160928-cip

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	—	Final	2016-September-28

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