Cisco Security Advisory
Cisco Wireless LAN Controller Management Interface Authentication Bypass Vulnerability
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:X/RL:X/RC:X
-
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 management interface
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 credentials.
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 this advisory.
Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wlc-auth-bypass-JRNhV4fF
-
Vulnerable Products
This vulnerability affects the following Cisco products if they are running Cisco WLC Software Release 8.10.151.0 or Release 8.10.162.0 and have macfilter radius compatibility configured as Other:
- 3504 Wireless Controller
- 5520 Wireless Controller
- 8540 Wireless Controller
- Mobility Express
- 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:
- 8.10.151.4 to 8.10.151.10
- 8.10.162.1 to 8.10.162.14
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............................... 0Products 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 Cisco products:
- 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
-
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 CLI commands:
wlc > config macfilter radius-compat cisco
wlc > config macfilter radius-compat freeFor 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 such environment.
-
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
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 8.10.142.0 and earlier Not vulnerable 8.10.151.0 and later 8.10.171.0 To download the software from the Software Center on Cisco.com, do the following:
- Click Browse all.
- Choose Wireless > Wireless LAN Controller > Standalone Controllers.
- Choose a specific product from the right pane of the product selector.
- 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 advisory.
-
The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
-
Cisco would like to thank a security researcher with Bispok for reporting this vulnerability.
-
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
-
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.