Headline
CVE-2022-20945: Cisco Security Advisory: Cisco Catalyst 9100 Series Access Points Association Request Denial of Service Vulnerability
A vulnerability in the 802.11 association frame validation of Cisco Catalyst 9100 Series Access Points (APs) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation of certain parameters within association request frames received by the AP. An attacker could exploit this vulnerability by sending a crafted 802.11 association request to a nearby device. An exploit could allow the attacker to unexpectedly reload the device, resulting in a DoS condition.
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
The process to upgrade an AP requires administrators to upgrade the wireless controller to which the AP is registered. Customers are advised to upgrade to an appropriate fixed software release as indicated in the following table(s):
Cisco Catalyst 9800 Wireless Controller Software Release
First Fixed Release
Earlier than 17.6
Not vulnerable.
17.6
17.6.4
17.7
Migrate to a fixed release.
17.8
Migrate to a fixed release.
17.9
Not vulnerable.
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.