Cisco NX-OS Software CLI Arbitrary Command Execution Vulnerability

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Updated:June 20, 2018
Document ID:1529512500762611

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Cisco Security Advisory

Cisco NX-OS Software CLI Arbitrary Command Execution Vulnerability

High
Advisory ID:
cisco-sa-20180620-nx-os-cli-execution
First Published:
2018 June 20 16:00 GMT
Last Updated: 
2020 August 26 20:48 GMT
Version 1.2:
Final
Workarounds:
No workarounds available
CVE-2018-0306
CWE-20
CVSS Score:
Base 7.8Click Icon to Copy Verbose Score
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:X/RL:X/RC:X
CVE-2018-0306
CWE-20

Summary

  • A vulnerability in the CLI parser of Cisco NX-OS Software could allow an authenticated, local attacker to perform a command-injection attack on an affected device.

    The vulnerability is due to insufficient input validation of command arguments. An attacker could exploit this vulnerability by injecting malicious command arguments into a vulnerable CLI command. A successful exploit could allow the attacker to execute arbitrary commands with root privileges on the affected device.

    Note: This vulnerability requires that any feature license is uploaded to the device. The vulnerability does not require that the license be used.

    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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180620-nx-os-cli-execution

    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 products if they are running a vulnerable version of Cisco NX-OS Software:

    • MDS 9000 Series Multilayer Switches
    • Nexus 1000V Series Switches
    • Nexus 1100 Series Cloud Services Platforms
    • Nexus 2000 Series Fabric Extenders
    • 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 standalone NX-OS mode
    • Nexus 9500 R-Series Line Cards and Fabric Modules

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

    This vulnerability requires that any feature license is uploaded to the device. The vulnerability does not require that the license be used.

    Administrators can use the show license usage command to see if a license is installed, as in the following example:

    switch# show license usage
Feature           Ins     Lic    Status   Expiry   Date  Comments 
                              Count
-----------------------------------------------------------------
MPLS_PKG          Yes      -     Unused   never             -
STORAGE-ENT       Yes      -     Unused   never             -
VDC_LICENSES      Yes      12    In use   never             -
FCOE-N77-F324FQ   No        0    Unused                     -
FCOE-N77-F348XP   No        0    Unused                     -
FCOE-N7K-F248XP   No        0    Unused                     -
    .
        .
        .
        ------------------------------------------------------------------

    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 the following Cisco products:

    • Firepower 2100 Series
    • Firepower 4100 Series Next-Generation Firewall
    • Firepower 9300 Security Appliance
    • Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode
    • UCS 6100 Series Fabric Interconnects
    • UCS 6200 Series Fabric Interconnects
    • UCS 6300 Series Fabric Interconnects

    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.

    MDS 9000 Series Multilayer Switches: CSCve51693

    Cisco NX-OS Software First Fixed Release for This Vulnerability
    		 First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    5.2 6.2(25) 8.1(1a) or 8.2(1)
    6.2 6.2(25) 8.1(1a) or 8.2(1)
    7.3 8.1(1a) 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: CSCve91663

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


    Nexus 3000 Series Switches: CSCve51693

    Cisco NX-OS Software First Fixed Release for This Vulnerability
    		 First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 7.0(3)I4 7.0(3)I4(8) 7.0(3)I7(4)
    7.0(3)I4 7.0(3)I4(8) 7.0(3)I7(4)
    7.0(3)I5 7.0(3)I7(2) 7.0(3)I7(4)
    7.0(3)I6 7.0(3)I7(2) 7.0(3)I7(4)
    7.0(3)I7 7.0(3)I7(2) 7.0(3)I7(4)


    Nexus 3500 Platform Switches: CSCve91634

    Cisco NX-OS Software First Fixed Release for This Vulnerability
    		 First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    6.0 6.0(2)A8(7) 7.0(3)I7(4)
    7.0.3 Not vulnerable 7.0(3)I7(4)


    Nexus 2000, 5500, 5600, and 6000 Series Switches: CSCve91659

    Cisco NX-OS Software   First Fixed Release for This Vulnerability
    		 First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    6.0 7.1(5)N1(1b) 7.3(3)N1(1)
    7.0 7.1(5)N1(1b) 7.3(3)N1(1)
    7.1 7.1(5)N1(1b) 7.3(3)N1(1)
    7.2 7.3(3)N1(1) 7.3(3)N1(1)
    7.3 7.3(3)N1(1) 7.3(3)N1(1)


    Nexus 7000 and 7700 Series Switches: CSCve51693

    Cisco NX-OS Software 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 7.3(2)D1(1A) 8.1(2) or 8.2(1)
    7.3 7.3(2)D1(1A) 8.1(2) or 8.2(1)
    8.0 8.1(2) 8.1(2) or 8.2(1)
    8.1 8.1(2) 8.1(2) or 8.2(1)
    8.2 Not vulnerable Not vulnerable


    Nexus 9000 Series Switches in Standalone NX-OS Mode: CSCve51693

    Cisco NX-OS Software First Fixed Release for This Vulnerability
    		 First Fixed Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 7.0(3)I4 7.0(3)I4(8) 7.0(3)I7(4)
    7.0(3)I4 7.0(3)I4(8) 7.0(3)I7(4)
    7.0(3)I5 7.0(3)I7(2) 7.0(3)I7(4)
    7.0(3)I6 7.0(3)I7(2) 7.0(3)I7(4)
    7.0(3)I7 7.0(3)I7(2) 7.0(3)I7(4)


    Nexus 9500 R-Series Line Cards and Fabric Modules and Nexus 3600 Platform Switches: CSCve51693

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

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 internal security testing.

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
    1.2 Added additional First Fixed Release versions to the Fixed Releases tables. Fixed Software Final 2020-AUG-26
    1.1 Updated Fixed Releases for the MDS platform. Fixed Software Final 2018-JUL-05
    1.0 Initial public release. — Final 2018-JUN-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