CVE-2017-6655: Cisco Security Advisory: Cisco NX-OS Software Fibre Channel over Ethernet Denial of Service Vulnerability

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Summary

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• A vulnerability in the Fibre Channel over Ethernet (FCoE) protocol implementation in Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition when an FCoE-related process unexpectedly reloads.

  The vulnerability is due to a lack of proper FCoE frame padding validation. An attacker could exploit this vulnerability by sending a stream of crafted FCoE frames to the targeted device. An exploit could allow the attacker to cause a DoS condition, which would impact FCoE traffic passing through the device. The attacker’s server must be directly connected to the FCoE interface on the device that is running Cisco NX-OS Software to exploit this vulnerability.

  There are no workarounds that address this vulnerability.

  This advisory is available at the following link:
  https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170607-nxos

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Affected Products

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• This vulnerability affects Cisco NX-OS Software on the following Cisco devices when they are configured for FCoE:

  • Multilayer Director Switches
  • Nexus 7000 Series Switches
  • Nexus 7700 Series Switches

  For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory.

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

  Cisco has confirmed that this vulnerability does not affect the following Cisco products:

  • Nexus 1000V Series Switches
  • Nexus 2000 Series Fabric Extenders
  • Nexus 3000 Series Switches
  • Nexus 3500 Platform Switches
  • Nexus 4000 Series Switches
  • Nexus 5000 Series Switches
  • Nexus 5500 Platform Switches
  • Nexus 5600 Platform Switches
  • Nexus 6000 Series Switches
  • Nexus 9000 Series Switches in Application Centric Infrastructure (ACI) mode
  • Nexus 9000 Series Switches in NX-OS mode
  • Unified Computing System (UCS) 6100 Series Fabric Interconnects
  • UCS 6200 Series Fabric Interconnects

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Workarounds

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• There are no workarounds that address this vulnerability.

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Fixed Software

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• For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.

  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.

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Exploitation and Public Announcements

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• 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.

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Source

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• This vulnerability was found during internal security testing.

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Cisco Security Vulnerability Policy

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• To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

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URL

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Revision History

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• Version

  Description

  Section

  Status

  Date

  1.1

  Moved the Nexus 5000 platforms to the list of products that have been confirmed to be not vulnerable.

  Affected Products

  Final

  2017-June-08

  1.0

  Initial public release.

  -

  Final

  2017-June-07

  Show Less

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Legal Disclaimer

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• 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 standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.

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