Headline
CVE-2021-40119: Cisco Security Advisory: Cisco Policy Suite Static SSH Keys Vulnerability
A vulnerability in the key-based SSH authentication mechanism of Cisco Policy Suite could allow an unauthenticated, remote attacker to log in to an affected system as the root user. This vulnerability is due to the re-use of static SSH keys across installations. An attacker could exploit this vulnerability by extracting a key from a system under their control. A successful exploit could allow the attacker to log in to an affected system as the root user.
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.htmlAdditionally, 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 take appropriate actions as indicated in the following table:
Cisco Policy Suite Software Release
Vulnerability status
Remediation action
Earlier than 20.2.0
Vulnerable
Upgrade to 21.1.0.
20.2.0
Vulnerable
Contact TAC to get a patch installed.
21.1.0
Vulnerable
Change the default SSH keys.
21.2.0 and later
Not vulnerable
See footnote 1
1. Releases 21.2.0 and later will automatically create new SSH keys during installation but not during an upgrade. If a device is upgraded from 21.1.0, the keys should still be changed by using the following procedure.
Change the Default SSH Keys
To generate new SSH keys and propagate them to all the machines in the deployment, follow these steps:
Step 1
To generate new keys, execute the following command on installer VM (Cluster Manager):
/var/qps/install/current/scripts/bin/support/manage_sshkey.sh --create
Step 2
Update keys on CPS VMs and installer VM (Cluster Manager):
/var/qps/install/current/scripts/bin/support/manage_sshkey.sh --update
This procedure is documented in CPS Migration and Upgrade Guide, Release 21.1.0.
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.