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AUSCERT External Security Bulletin Redistribution
Cisco Wireless LAN Controller Management Interface
Authentication Bypass Vulnerability
14 April 2022
AusCERT Security Bulletin Summary
Product: Cisco Wireless LAN Controller
Publisher: Cisco Systems
Operating System: Cisco
CVE Names: CVE-2022-20695
Comment: CVSS (Max): 10.0 CVE-2022-20695 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
CVSS Source: Cisco Systems
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Cisco Wireless LAN Controller Management Interface Authentication Bypass
Advisory ID: cisco-sa-wlc-auth-bypass-JRNhV4fF
First Published: 2022 April 13 16:00 GMT
Version 1.0: Final
Cisco Bug IDs: CSCwa43249
CVE Names: CVE-2022-20695
o A vulnerability in the authentication functionality of Cisco Wireless LAN
Controller (WLC) Software could allow an unauthenticated, remote attacker
to bypass authentication controls and log in to the device through the
This vulnerability is due to the improper implementation of the password
validation algorithm. An attacker could exploit this vulnerability by
logging in to an affected device with crafted credentials. A successful
exploit could allow the attacker to bypass authentication and log in to the
device as an administrator. The attacker could obtain privileges that are
the same level as an administrative user but it depends on the crafted
Note: This vulnerability exists because of a non-default device
configuration that must be present for it to be exploitable. For details
about the vulnerable configuration, see the Vulnerable Products section of
Cisco has released software updates that address this vulnerability. There
are workarounds that address this vulnerability.
This advisory is available at the following link:
o Vulnerable Products
This vulnerability affects the following Cisco products if they are running
Cisco WLC Software Release 22.214.171.124 or Release 126.96.36.199 and have
macfilter radius compatibility configured as Other :
3504 Wireless Controller
5520 Wireless Controller
8540 Wireless Controller
Virtual Wireless Controller (vWLC)
Note: The vulnerable releases noted above are available in the Software
Center on Cisco.com. In addition, specific customers have been given the
following vulnerable escalation builds that are not in the Software Center:
188.8.131.52 to 184.108.40.206
220.127.116.11 to 18.104.22.168
Determine the Configuration
To determine whether the Cisco WLC configuration is vulnerable, issue the
show macfilter summary CLI command. If RADIUS compatibility mode is other ,
as shown in the following example, the device is considered vulnerable:
wlc > show macfilter summary
MAC Filter RADIUS Compatibility mode............. Other
MAC Filter Delimiter............................. Single-Hyphen
MAC Filter Entries............................... 0
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
Catalyst 9800 Embedded Wireless Controller for Catalyst 9300, 9400, and
9500 Series Switches
Catalyst 9800 Series Wireless Controllers
Catalyst 9800 Wireless Controller for Cloud
Embedded Wireless Controller on Catalyst Access Points
Wireless LAN Controller (WLC) AireOS products not listed in the
Vulnerable Products section
o There are workarounds that addresses this vulnerability. Choose one of the
following based on the environment:
Option 1: No Macfilters in the Environment
Customers who do not use macfilters can reset the macfilter radius
compatibility mode to the default value using the following CLI command:
wlc > config macfilter radius-compat cisco
Option 2: Macfilters in the Environment
Customers who use macfilters and who are able to change the radius server
configuration to match other possible compatibility modes can modify the
macfilter compatibility to either cisco or free using one of the following
wlc > config macfilter radius-compat cisco
wlc > config macfilter radius-compat free
For more information about the different macfilter compatibility modes, see
Cisco Wireless Controller Command Reference .
While these workarounds have been deployed and were 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
o 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:
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
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
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
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
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 Wireless LAN Controller Release First Fixed Release
8.9 and earlier Not vulnerable
22.214.171.124 and earlier Not vulnerable
126.96.36.199 and later 188.8.131.52
To download the software from the Software Center on Cisco.com, do the
1. Click Browse all .
2. Choose Wireless > Wireless LAN Controller > Standalone Controllers .
3. Choose a specific product from the right pane of the product selector.
4. Choose a hardware platform from the left pane of the software page.
The Cisco Product Security Incident Response Team (PSIRT) validates only
the affected and fixed release information that is documented in this
Exploitation and Public Announcements
o The Cisco PSIRT is not aware of any public announcements or malicious use
of the vulnerability that is described in this advisory.
o Cisco would like to thank a security researcher with Bispok for reporting
Cisco Security Vulnerability Policy
o To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy . This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
| Version | Description | Section | Status | Date |
| 1.0 | Initial public release. | - | Final | 2022-APR-13 |
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