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Cisco Security Advisory

Cisco FXOS, NX-OS, and UCS Manager Software Cisco Discovery Protocol Denial of Service Vulnerability

High
Advisory ID:
cisco-sa-20180620-nxos-cdp
First Published:
2018 June 20 16:00 GMT
Last Updated:
2018 July 5 21:12 GMT
Version 1.1:
Final
Workarounds:
No workarounds available
CVE-2018-0331
CWE-399
CVSS Score:
Base 7.4Click Icon to Copy Verbose Score
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
CVE-2018-0331
CWE-399

Summary

  • A vulnerability in the Cisco Discovery Protocol (formerly known as CDP) subsystem of devices running, or based on, Cisco NX-OS Software contain a vulnerability that could allow an unauthenticated, adjacent attacker to create a denial of service (DoS) condition.

    The vulnerability is due to a failure to properly validate certain fields within a Cisco Discovery Protocol message prior to processing it. An attacker with the ability to submit a Cisco Discovery Protocol message designed to trigger the issue could cause a DoS condition on an affected device while the device restarts.

    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-20180620-nxos-cdp

    This advisory is part of the June 2018 Cisco FXOS and NX-OS Software Security Advisory Collection, which includes 24 Cisco Security Advisories that describe 24 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: June 2018 Cisco FXOS and NX-OS Software Security Advisory Collection.

Affected Products

  • Vulnerable Products

    This vulnerability affects the following Cisco products if they are running a vulnerable release of Cisco FXOS Software, Cisco NX-OS Software, or Cisco UCS Manager Software:

    • Firepower 4100 Series Next-Generation Firewall
    • Firepower 9300 Security Appliance
    • MDS 9000 Series Multilayer Director Switches
    • Nexus 1000V Series Switches
    • Nexus 1100 Series Cloud Services Platforms
    • Nexus 2000 Series Switches
    • Nexus 3000 Series Switches
    • Nexus 3500 Platform Switches
    • Nexus 3600 Platform Switches
    • Nexus 5500 Platform Switches
    • Nexus 5600 Platform Switches
    • Nexus 6000 Series Switches
    • Nexus 7000 Series Switches
    • Nexus 7700 Series Switches
    • Nexus 9000 Series Switches in NX-OS mode
    • Nexus 9500 R-Series Line Cards and Fabric Modules
    • UCS 6100 Series Fabric Interconnects
    • UCS 6200 Series Fabric Interconnects
    • UCS 6300 Series Fabric Interconnects

    For information about which Cisco FXOS, NX-OS, and UCS Manager Software releases are vulnerable, see the Fixed Software section of this advisory.

    Assessing the Cisco Discovery Protocol Configuration

    To determine whether a device is configured to use Cisco Discovery Protocol, administrators can log in to the device and issue the show cdp global command in the CLI. If the device is configured to use Cisco Discovery Protocol, the output of the command will be similar to the following:

    CLI(config)# show cdp global 
Global CDP information:
  CDP enabled globally
  Refresh time is 60 seconds
  Hold time is 180 seconds
  CDPv2 advertisements is enabled
  DeviceID TLV in System-Name(Default) Format

    If use of Cisco Discovery Protocol is configured for only specific interfaces of a device, administrators can instead use the show cdp interface command in the CLI to determine which interfaces are configured to use Cisco Discovery Protocol.

    Determining the Cisco FXOS Software Release

    Administrators can check the release of Cisco FXOS Software that is running on a device by using the following commands in the device CLI or by navigating to the Overview tab in the Admin portal. The following example shows the output of the show version CLI command on a device that is running Cisco FXOS Software Release 2.2(2.14), as identified in the Package-Vers field of the command output:

    QP4120B1 # scope system
QP4120B1 /system # show version
FPRM:
Running-Vers: 4.2(2.15)
Package-Vers: 2.2(2.14)
Activate-Status: Ready

    Determining the Cisco NX-OS Software Release

    Administrators can check the release of Cisco NX-OS Software that is running on a device by using the show version command in the device CLI. The following example shows the output of this command on a device that is running Cisco NX-OS Software Release 7.3(2)D1(1):

    nxos-switch# show version
    Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Documents: http://www.cisco.com/en/US/products/ps9372/tsd_products_support_series_home.html
Copyright (c) 2002-2017, Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained in this software are
owned by other third parties and used and distributed under
license. Certain components of this software are licensed under
the GNU General Public License (GPL) version 2.0 or the GNU
Lesser General Public License (LGPL) Version 2.1. A copy of each
such license is available at
http://www.opensource.org/licenses/gpl-2.0.php and
http://www.opensource.org/licenses/lgpl-2.1.php
Software
  BIOS:      version 2.12.0
  kickstart: version 7.3(2)D1(1)
  system:    version 7.3(2)D1(1)
.
.
.

    Products Confirmed Not Vulnerable

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

    Cisco has confirmed that this vulnerability does not affect Cisco Firepower 2100 Series and Cisco Nexus 9000 Series Switches in Application Centric Infrastructure (ACI) mode.

    Cisco has not investigated whether this vulnerability affects Cisco Nexus 4000 Series Switches, Cisco Nexus 5010 Switches, or Cisco Nexus 5020 Switches because those products have reached end-of-life status. For more information, refer to the End-of-Sale and End-of-Life Announcement for the Cisco Nexus 4000 Series Switch Modules for IBM BladeCenter and the End-of-Sale and End-of-Life Announcement for the Cisco Nexus 5010 and Nexus 5020 Switches.

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:
    https://www.cisco.com/c/en/us/products/end-user-license-agreement.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 TAC:
    https://www.cisco.com/c/en/us/support/web/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

    Customers are advised to upgrade to an appropriate release as indicated in the applicable table in this section. To help ensure a complete upgrade solution, consider that this advisory is part of a collection. For a complete list of the advisories in the collection and links to them, see Cisco Event Response: June 2018 Cisco FXOS and NX-OS Software Security Advisory Collection.

    In the following tables, the left column lists releases of Cisco FXOS or NX-OS Software. The center column indicates whether a release is affected by the vulnerability described in this advisory and the first release that includes the fix for this vulnerability. The right column indicates whether a release is affected by all the vulnerabilities described in this collection of advisories and which release includes fixes for those vulnerabilities.

    Firepower 4100 Series Next-Generation Firewall: CSCve41007

    Cisco FXOS Software Release
    		First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    1.1 2.0.1.152
    		 2.0.1.159
    2.0 2.0.1.152 2.0.1.159
    2.1.1 2.1.1.86 2.1.1.86
    2.2 2.2.1.70 2.2.2.17 or 2.3.1.0
    2.2.2 2.2.2.14 2.2.2.17 or 2.3.1.0
    2.3 Not vulnerable
    		 2.3.1.58

    Firepower 9300 Security Appliance: CSCve41007

    Cisco FXOS Software Release
    		 First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    1.1
    		 2.0.1.152
    		 2.0.1.159
    2.0 2.0.1.152 2.0.1.159
    2.1.1 2.1.1.86 2.1.1.86
    2.2 2.2.1.70 2.2.2.17 or 2.3.1.0
    2.2.2 2.2.2.14 2.2.2.17 or 2.3.1.0
    2.3 Not vulnerable
    		 2.3.158

    MDS 9000 Series Multilayer Switches: CSCve40970
    Cisco NX-OS Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    5.2 6.2(21)
    		 8.1(1a) or 8.2(1)
    6.2 6.2(21) 8.1(1a) or 8.2(1)
    7.2 7.2(2)D1(3) 8.1(1a) or 8.2(1)
    7.3 7.3(2)D1(1) 8.1(1a) or 8.2(1)
    8.1 8.1(1a) 8.1(1a) or 8.2(1)
    8.2 Not vulnerable
    		 Not vulnerable

    Nexus 1000V Series Switches and Nexus 1100 Series Cloud Services Platforms: CSCve40992

    Cisco NX-OS Software Release
    		 First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 5.2
    		 Affected; migrate 5.2(1)SV3(3.15)
    5.2 5.2(1)SV3(3.15) 5.2(1)SV3(3.15)

    Nexus 3000 Series Switches: CSCve40965
    Cisco NX-OS Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 7.0(3)I4 Affected; migrate 7.0(3)I7(4)
    7.0(3)I4 7.0(3)I4(7) 7.0(3)I7(4)
    7.0(3)I5 7.0(3)I5(3b) 7.0(3)I7(4)
    7.0(3)I6 7.0(3)I6(2) 7.0(3)I7(4)
    7.0(3)I7 7.0(3)I7(1) 7.0(3)I7(4)

    Nexus 3500 Platform Switches: CSCve40953

    Cisco NX-OS Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    6.0 6.0(2)A8(5) 7.0(3)I7(4)
    7.0.3 7.0(3)I7(2) 7.0(3)I7(4)

    Nexus 2000, 5500, 5600, and 6000 Series Switches: CSCve40978

    Cisco NX-OS Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    6.0 Affected; migrate 7.3(3)N1(1)
    7.0 Affected; migrate 7.3(3)N1(1)
    7.1 7.1(5)N1(1) 7.3(3)N1(1)
    7.2 Affected; migrate 7.3(3)N1(1)8.1(2) or 8.2(1)
    7.3 7.3(3)N1(1) 7.3(3)N1(1)

    Nexus 7000 and 7700 Series Switches: CSCve40970

    Cisco NX-OS Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    6.2 6.2(20) 8.1(2) or 8.2(1)
    7.2 7.2(2)D1(3) 8.1(2) or 8.2(1)
    7.3 7.3(2)D1(1) 8.1(2) or 8.2(1)
    8.0 Affected; migrate 8.1(2) or 8.2(1)
    8.1 8.1(2) 8.1(2) or 8.2(1)
    8.2 8.2(1) 8.1(2) or 8.2(1)

    Nexus 9000 Series Switches in standalone NX-OS mode: CSCve40943
    Cisco NX-OS Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 7.0(3)I4 Affected; migrate 7.0(3)I7(4)
    7.0(3)I4 7.0(3)I4(7) 7.0(3)I7(4)
    7.0(3)I5 Affected; migrate 7.0(3)I7(4)
    7.0(3)I6 7.0(3)I6(2) 7.0(3)I7(4)
    7.0(3)I7 7.0(3)I7(1) 7.0(3)I7(4)

    Nexus 9500 R-Series Line Cards and Fabric Modules and Nexus 3600 Platform Switches: CSCve41000

    Cisco NX-OS Software Release
    		 First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    7.0 7.0(3)F3(1) 7.0(3)F3(3a)

    UCS 6100, 6200, and 6300 Fabric Interconnects: CSCvc89242
    Cisco UCS Manager Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 2.2 Affected; migrate 3.2(2b)
    2.2 2.2(8g) 3.2(2b)
    2.5 Affected; migrate 3.2(2b)
    3.0 Affected; migrate 3.2(2b)
    3.1 3.1(2f) 3.2(2b)
    3.2 Not affected 3.2(2b)

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 Cisco TAC support case.

Cisco Security Vulnerability Policy

  • 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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Revision History

  • Version Description Section Status Date
    1.1 Updated the Fixed Release information for FXOS and MDS products. Fixed Software Final 2018-July-05
    1.0 Initial public release. - Final 2018-June-20
    Show Less

Cisco Security Vulnerability Policy

  • 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.

Subscribe to Cisco Security Notifications

Related to This Advisory