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             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

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        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

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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.

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