Summary

• A vulnerability in the Common Execution Environment (CEE) ConfD CLI of Cisco Ultra Cloud Core - Subscriber Microservices Infrastructure (SMI) software could allow an authenticated, local attacker to escalate privileges on an affected device.

  This vulnerability is due to insufficient access control in the affected CLI. An attacker could exploit this vulnerability by authenticating as a CEE ConfD CLI user and executing a specific CLI command. A successful exploit could allow an attacker to access privileged containers with root privileges.

  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-uccsmi-prvesc-BQHGe4cm

Affected Products

• Vulnerable Products

  This vulnerability affects Cisco Ultra Cloud Core SMI.

  For information about which Cisco 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.

Workarounds

• There are no workarounds that address this vulnerability. However, administrators may reduce the scope of this vulnerability by preventing nonadministrative users from executing CEE ConfD CLI commands. Using administrative credentials, enter the following commands:

  config
  nacm cmd-exec-default deny
  nacm rule-list admin
  group [ admin ]
  cmdrule cmd-any-access
   action permit
  exit
  exit
  commit

  While this mitigation has been deployed and was proven successful in a test environment, customers should determine the applicability and effectiveness in their own environment and under their own use conditions. Customers should be aware that any workaround or mitigation that is implemented may negatively impact the functionality or performance of their network based on intrinsic customer deployment scenarios and limitations. Customers should not deploy any workarounds or mitigations before first evaluating the applicability to their own environment and any impact to such environment.

Fixed Software

• Cisco has released free software updates that address the vulnerability described in this advisory. Customers with service contracts that entitle them to regular software updates should obtain security fixes through their usual update channels.

  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.

  The Cisco Support and Downloads page on Cisco.com provides information about licensing and downloads. This page can also display customer device support coverage for customers who use the My Devices tool.

  When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories 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 fixed software release as indicated in the following table(s):

  Cisco Ultra Cloud Core SMI Release	First Fixed Release
  2020.02.2	2020.02.2.47
  2020.02.6	Migrate to a fixed release.
  2020.02.7	2020.02.7.07

  The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.

Exploitation and Public Announcements

• The Cisco 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 by Andrew Kim of the Cisco Advanced Security Initiatives Group (ASIG).

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-uccsmi-prvesc-BQHGe4cm

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2022-MAR-02

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