Summary

• A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, local attacker with administrator credentials to execute arbitrary commands on the underlying Linux operating system of an attached line card with the privilege level of root.

  The vulnerability is due to insufficient validation of arguments passed to a specific CLI command on the affected device. An attacker could exploit this vulnerability by including malicious input as the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system of an attached line card with elevated privileges. An attacker would need valid administrator credentials to exploit this vulnerability.

  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-20190515-nxos-linecardinj-1769

Affected Products

• Vulnerable Products

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

  • Nexus 3000 Series Switches
  • Nexus 3500 Platform Switches
  • Nexus 3600 Platform Switches
  • Nexus 9000 Series Switches in standalone NX-OS mode
  • Nexus 9500 R-Series Switching Platform

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

  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
  • Firepower 9300 Security Appliances
  • MDS 9000 Series Multilayer Switches
  • Nexus 1000V Switch for Microsoft Hyper-V
  • Nexus 1000V Switch for VMware vSphere
  • Nexus 5500 Platform Switches
  • Nexus 5600 Platform Switches
  • Nexus 6000 Series Switches
  • Nexus 7000 Series Switches
  • Nexus 7700 Series Switches
  • Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode
  • UCS 6200 Series Fabric Interconnects
  • UCS 6300 Series Fabric Interconnects
  • UCS 6400 Series Fabric Interconnects

Details

• Cisco has disclosed several similar CLI command injection vulnerabilities. They differ primarily in affected products and software versions. This table shows the affected products for each vulnerability by Cisco bug ID and CVE ID.

  Security Advisory	FP 4100/ 9300	MDS 9K/ N7K/ N77001	N1000V MS/VM	N3K/N3500/ N9K-NXOS	N3600/ N9500R	N5500K/ N5600/ N6K	UCS 6200/ UCS 6300 UCS 64002
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1735)	N/A	CSCvj63728	CSCvk52969 CSCvk52985	CSCvj63877 CSCvk52971	CSCvk52988	CSCvk52972	CSCvk52975
  Cisco NX-OS Software Line Card Command Injection Vulnerability (CVE-2019-1769)	N/A	N/A	N/A	CSCvh20032	CSCvj00299	N/A	N/A
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1770)	N/A	CSCvh758671	CSCvi92240 CSCvk36294	CSCvh75958 CSCvi92242	CSCvi92239	CSCvi92243	N/A
  Cisco NX-OS Software Command Injection Vulnerabilities (CVE-2019-1774, CVE-2019-1775)	N/A	CSCvh75895 CSCvh75909	N/A	CSCvh75968 CSCvh75976 CSCvi99197 CSCvi92258	CSCvi99195 CSCvi92256	CSCvi99198 CSCvi92260	N/A
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1776)	N/A	CSCvh20081	N/A	CSCvh20076 CSCvi96431	CSCvi96429	CSCvi96432	CSCvi964332
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1778)	N/A	N/A	N/A	CSCvh75996	CSCvj03877	N/A	N/A
  Cisco FXOS and NX-OS Software Command Injection Vulnerability (CVE-2019-1779)	CSCvj00418	CSCve51688	N/A	CSCvh76126	CSCvj00412	CSCvj00416	N/A
  Cisco FXOS and NX-OS Software Command Injection Vulnerability (CVE-2019-1780)	CSCvi92332	CSCvi01440	N/A	CSCvi01431 CSCvi92328	CSCvi92326	CSCvi92329	N/A
  Cisco FXOS and NX-OS Software Command Injection Vulnerabilities (CVE-2019-1781, CVE-2019-1782)	CSCvi96527 CSCvi92130	CSCvi01448 CSCvh20389	N/A	CSCvi01445 CSCvh20027 CSCvi96524 CSCvi92126	CSCvi96522 CSCvi91985	CSCvi96525 CSCvi92128	CSCvi965262 CSCvi921292
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1783)	N/A	CSCvi422811	N/A	N/A	N/A	CSCvj03966	N/A
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1784)	N/A	CSCvi422921	N/A	N/A	N/A	CSCvj12273	CSCvj122742
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1790)	N/A	CSCvh20112	N/A	CSCvh20096	CSCvi96504	CSCvi96509	CSCvi965102
  Cisco NX-OS Software Command Injection Vulnerability (CVE-2019-1791)	N/A	CSCvj63667	N/A	CSCvj63270 CSCvk50873	CSCvk50889	CSCvk50876	N/A
  Cisco FXOS and NX-OS Software Command Injection Vulnerability (CVE-2019-1795)	CSCvh66259	CSCvh20359	CSCvh66257 CSCvk30761	CSCvh20029 CSCvh66219	CSCvh66202	CSCvh66214	CSCvh662432

  1. CSCvh75867, CSCvi42281, and CSCvi42292 apply to only Nexus 7000 Series and Nexus 7700 Series Switches. The MDS 9000 Series Multilayer Switches are not affected by these vulnerabilities.
  2. CSCvk52975 applies to UCS 6200, 6300, and 6400. For all other UCS defects, only UCS 6200 and 6300 are affected (and UCS 6400 is not affected).
  

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

  No upgrade action is necessary for customers who have already applied a recommended release to address the March 2019 Cisco FXOS and NX-OS Software bundle. See Cisco Event Response: March 2019 Cisco FXOS and NX-OS Software Security Advisory Bundled Publication for a list of advisories in the bundle.

  Customers who have not applied a recommended release to address the March 2019 bundle are advised to upgrade to an appropriate release as indicated in the applicable table in this section. In the following tables, the left column lists Cisco NX-OS Software releases. The right column indicates the first release that includes the fix for this vulnerability.

  Nexus 3000 Series Switches, Nexus 3500 Platform Switches, and Nexus 9000 Series Switches in Standalone NX-OS Mode: CSCvh20032

  Cisco NX-OS Software Release	First Fixed Release for This Vulnerability
  Prior to 7.0(3)I4	7.0(3)I4(8)
  7.0(3)I4	7.0(3)I4(8)
  7.0(3)I7	7.0(3)I7(4)
  9.2(1)	Not vulnerable

  Nexus 3600 Platform Switches and Nexus 9500 R-Series Switching Platform: CSCvj00299

  Cisco NX-OS Software Release	First Fixed Release for This Vulnerability
  7.0(3)	7.0(3)F3(5)
  9.2	Not vulnerable

  
  

  Additional Resources

  For help determining the best Cisco NX-OS Software release for a Cisco Nexus Switch, administrators can refer to the following Recommended Releases documents. If a security advisory recommends a later release, Cisco recommends following the advisory guidance.

  Cisco MDS Series Switches
  Cisco Nexus 1000V for VMware Switch
  Cisco Nexus 3000 Series and 3500 Series Switches
  Cisco Nexus 5000 Series Switches
  Cisco Nexus 5500 Platform Switches
  Cisco Nexus 6000 Series Switches
  Cisco Nexus 7000 Series Switches
  Cisco Nexus 9000 Series Switches
  Cisco Nexus 9000 Series ACI-Mode Switches

  For help determining the best Cisco NX-OS Software release for Cisco UCS, refer to the Recommended Releases documents in the release notes for the device.

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.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-linecardinj-1769

Revision History

• Version	Description	Section	Status	Date
  1.1	Updated the Fixed Release table for the Nexus 3000, 3500, and 9000.	Fixed Software	Final	2019-May-28
  1.0	Initial public release.	—	Final	2019-May-15

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