Summary

• A vulnerability in the REST API of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to perform a command injection attack and elevate privileges to root.

  This vulnerability is due to insufficient input validation for specific API endpoints. An attacker in a man-in-the-middle position could exploit this vulnerability by intercepting and modifying specific internode communications from one ISE persona to another ISE persona. A successful exploit could allow the attacker to run arbitrary commands with root privileges on the underlying operating system. To exploit this vulnerability, the attacker would need to decrypt HTTPS traffic between two ISE personas that are located on separate nodes.

  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-ise-priv-esc-UwqPrBM3

Affected Products

• Vulnerable Products

  This vulnerability affects Cisco devices if they are running a vulnerable release of Cisco ISE in a distributed deployment.

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

  Determine the Deployment Type

  To determine whether Cisco ISE is in a distributed deployment on a device, do the following:

  • For a device running Cisco ISE Release 3.0 or later, go to the Cisco ISE GUI and click the Menu icon. (This step is not necessary for devices running a release earlier than Release 3.0.)
  • Choose Administration > System > Deployment.
  • Click Deployment from the navigation pane on the left to see all of the Cisco ISE nodes that are part of the deployment.

  If the value under Role(s) is STANDALONE, the device is in a standalone deployment and is not affected by this vulnerability. If there is any value other than STANDALONE under Role(s), the device is in a distributed deployment and is affected by this vulnerability.

  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 standalone deployments of Cisco ISE.

Details

• For information about Cisco ISE nodes and personas, see the Cisco Identity Services Engine Installation Guide.

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 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

  In the following table(s), the left column lists Cisco software releases. The right 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. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section.

  Cisco Identity Services Engine Release	First Fixed Release
  2.4	Migrate to a fixed release.
  2.6	2.6 Patch11
  2.7	2.7 Patch5
  3.0	3.0 Patch4

  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

• Cisco would like to thank Alexander Polce Leary for reporting this vulnerability.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-priv-esc-UwqPrBM3

Revision History

• Version	Description	Section	Status	Date
  1.2	Updated fixed release information.	Fixed Releases	Final	2021-OCT-11
  1.1	Updated fixed release information.	Fixed Software	Final	2021-OCT-08
  1.0	Initial public release.	-	Final	2021-OCT-06

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