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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2023.1728 Cisco IOS XE Software for Wireless LAN Controllers CAPWAP Join Denial of Service Vulnerability 23 March 2023 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco IOS XE Software for Wireless LAN Controllers Publisher: Cisco Systems Operating System: Cisco Resolution: Patch/Upgrade CVE Names: CVE-2023-20100 Original Bulletin: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c9800-apjoin-dos-nXRHkt5 Comment: CVSS (Max): 6.8 CVE-2023-20100 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H) CVSS Source: Cisco Systems Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco IOS XE Software for Wireless LAN Controllers CAPWAP Join Denial of Service Vulnerability Priority: Medium Advisory ID: cisco-sa-c9800-apjoin-dos-nXRHkt5 First Published: 2023 March 22 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCwc17898 CVE Names: CVE-2023-20100 Summary o 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: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c9800-apjoin-dos-nXRHkt5 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 . Affected Products o Vulnerable Products 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 Workarounds o There are no workarounds that address this vulnerability. Fixed Software o 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: 1. Choose which advisories the tool will search-only this advisory, only advisories with a Critical or High Security Impact Rating (SIR) , or all advisories. 2. Enter a release number-for example, 15.9(3)M2 or 17.3.3. 3. Click Check . Exploitation and Public Announcements o 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. Source o This vulnerability was found during internal security testing. 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. Subscribe to Cisco Security Notifications o Subscribe Related to This Advisory o Cisco Event Response: March 2023 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication URL o https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c9800-apjoin-dos-nXRHkt5 Revision History o +----------+---------------------------+----------+--------+--------------+ | Version | Description | Section | Status | Date | +----------+---------------------------+----------+--------+--------------+ | 1.0 | Initial public release. | - | Final | 2023-MAR-22 | +----------+---------------------------+----------+--------+--------------+ Legal Disclaimer o 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. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: https://auscert.org.au/gpg-key/ iQIVAwUBZBu63skNZI30y1K9AQhgtg//RHuSFM+6Bae7RuFukBDxVIojO0gL/x/N U2hgMKqZl7qEel34VIPh8/hZHsr5CiLYmRIASgp/ShMNF3eF2RJj9JiVP6tD/rrT JTYA+yfdVHk8bbZoagYy27ZSm91v7/x24ybVlXvbJ16GjYL1A5t72C73WM3VoGvv uZcrT/5+erhuKwD/wnZ6wsVfPF+L03py+YpQcBMbmasdUcp0tiIF0mJ8uhuqdh1p ndgJ4Qj238MVzFBbO1dlfdBbF8m/fjrPBZPAFE614eH4DavIoT1fAkcpV29rcw1a GIhsLWu1t/8bNvWDQh3ePlOSUw8Gt5ZDvLVEcKMmClaE1fIf/mZiGAgkzfddaf2F YR0Bueqiweae31K5WoyEBsXx0yRgk/0iHvgAyzZLcdoojBkNzgTe3C8+Krgay/4M i11qnB4DYZe3IApgigvQdritAVDRpdG67B4bwC204is3XPhkRrKmwRPccZRcRynq oIMVdmMNz+KH310M4NO6Hzo7MJN8qeXJtpxWssSu/2jTFP6qDk9LuFQXnxJiZOwA Gvt6wVj2HII44ODnLsYN38W6sn75WoC7gjQmxCXVFZSviQGDFAFYVut9gvYDuaFj 85XmtwKwaCwK7e7QYzidbkPEHbA6riSuS3TkQsE3ophST0NYXJGl8GZdNVo1Vz2s es+TfoFo9tI= =cxOQ -----END PGP SIGNATURE-----