Cisco Security Advisory
Cisco IOS XE Software for Wireless LAN Controllers CAPWAP Join Denial of Service Vulnerability
A vulnerability in the access point (AP) joining process of the Control and Provisioning of Wireless Access Points (CAPWAP) protocol of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to a logic error that occurs when certain conditions are met during the AP joining process. An attacker could exploit this vulnerability by adding an AP that is under their control to the network. The attacker then must ensure that the AP successfully joins an affected wireless controller under certain conditions. Additionally, the attacker would need the ability to restart a valid AP that was previously connected to the controller. A successful exploit could allow the attacker to cause the affected device to restart unexpectedly, resulting in a DoS condition.
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:
This advisory is part of the March 2023 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2023 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
At the time of publication, this vulnerability affected the following Cisco products if they were running a vulnerable release of Cisco IOS XE Software for WLCs using the default configuration:
- Catalyst 9800 Embedded Wireless Controllers for Catalyst 9300, 9400, and 9500 Series Switches
- Catalyst 9800 Series Wireless Controllers
- Catalyst 9800-CL Wireless Controllers for Cloud
- Embedded Wireless Controllers on Catalyst Access Points
For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory.
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 Cisco products:
- IOS Software
- IOS XR Software
- Meraki products
- NX-OS Software
- WLC AireOS Software
There are no workarounds that address this vulnerability.
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.
Cisco IOS and IOS XE Software
To help customers determine their exposure to vulnerabilities in Cisco IOS and IOS XE Software, Cisco provides the Cisco Software Checker. This tool identifies any Cisco security advisories that impact a specific software release and the earliest release that fixes the vulnerabilities that are described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities that are described in all the advisories that the Software Checker identifies (“Combined First Fixed”).
To use the tool, go to the Cisco Software Checker page and follow the instructions. Alternatively, use the following form to determine whether a release is affected by any Cisco Security Advisory. To use the form, follow these steps:
- Choose which advisories the tool will search-only this advisory, only advisories with a Critical or High Security Impact Rating (SIR), or all advisories.
- Enter a release number-for example, 15.9(3)M2 or 17.3.3.
- Click Check.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
This vulnerability was found during internal security testing.
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 2023-MAR-22
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