Operating System:

[Cisco]

Published:

29 September 2022

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2022.4844
  Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family
              CAPWAP Mobility Denial of Service Vulnerability
                             29 September 2022

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Catalyst 9800-CL Wireless Controllers for Cloud
                   Catalyst 9300,9400 Embedded Wireless Controller
                   9500 Series Switches
                   Catalyst 9800 Series Wireless Controllers
Publisher:         Cisco Systems
Operating System:  Cisco
Resolution:        Patch/Upgrade
CVE Names:         CVE-2022-20856  

Original Bulletin: 
   https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c9800-mob-dos-342YAc6J

Comment: CVSS (Max):  8.6 CVE-2022-20856 (CVSS:3.1/AV:N/AC:L/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:L/PR:N/UI:N/S:C/C:N/I:N/A:H

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Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family CAPWAP
Mobility Denial of Service Vulnerability

Priority:        High
Advisory ID:     cisco-sa-c9800-mob-dos-342YAc6J
First Published: 2022 September 28 16:00 GMT
Version 1.0:     Final
Workarounds:     No workarounds available
Cisco Bug IDs:   CSCwa92678
CVE Names:       CVE-2022-20856
CWEs:            CWE-664

Summary

  o A vulnerability in the processing of Control and Provisioning of Wireless
    Access Points (CAPWAP) Mobility messages in Cisco IOS XE Wireless
    Controller Software for the Catalyst 9000 Family 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 and improper management of
    resources related to the handling of CAPWAP Mobility messages. An attacker
    could exploit this vulnerability by sending crafted CAPWAP Mobility packets
    to an affected device. A successful exploit could allow the attacker to
    exhaust resources on the affected device. This would cause the device to
    reload, 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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c9800-mob-dos-342YAc6J

    This advisory is part of the September 2022 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: September
    2022 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled
    Publication.

Affected Products

  o Vulnerable Products

    This vulnerability affects the following Cisco products if they are running
    a vulnerable release of Cisco IOS XE Software and are part of a Mobility
    group (disabled by default):

       Catalyst 9800-CL Wireless Controllers for Cloud
       Catalyst 9800 Embedded Wireless Controller for Catalyst 9300, 9400, and
        9500 Series Switches
       Catalyst 9800 Series Wireless Controllers

    For information about which Cisco software releases are vulnerable, see the
    Fixed Software section of this advisory.

    Determine the Device Configuration

    A device is affected by this vulnerability if it is part of a Mobility
    group. To determine whether a device is part of a Mobility group, use the
    command show wireless mobility summary . At the end of the output generated
    by this command, the Mobility peers are listed under Controllers configured
    in the Mobility Domain , including the current controller. If the only
    entry is the current device, then it is not part of a Mobility group and is
    not affected. If there are devices listed other than the current device,
    then it is part of a Mobility group and is affected.

    The example output below (layout changed for readability purposes) shows
    two devices: the device where the command was issued and its Mobility peer.
    Therefore, the example device is part of a Mobility group and is affected.

        WLC#show wireless mobility summary
        Mobility Summary


        Wireless Management VLAN: 999
        Wireless Management IP Address: 9.9.9.9
        Wireless Management IPv6 Address:
        Mobility Control Message DSCP Value: 48
        Mobility High Cipher : False
        Mobility DTLS Supported Ciphers: TLS_ECDHE_RSA_AES128_GCM_SHA256, TLS_RSA_AES256_GCM_SHA384, TLS_RSA_AES128_CBC_SHA
        Mobility Keepalive Interval/Count: 10/3
        Mobility Group Name: default
        Mobility Multicast Ipv4 address: 0.0.0.0
        Mobility Multicast Ipv6 address: ::
        Mobility MAC Address: 001e.ffff.ffff
        Mobility Domain Identifier: 0x34ac


        Controllers configured in the Mobility Domain:

        IP       Public   MAC Address    Group   Multicast Multicast Status PMTU
                 Ip                      Name    IPv4      IPv6
        9.9.9.9  N/A      001e.ffff.ffff default 0.0.0.0   ::        N/A    N/A
        9.9.9.10 9.9.9.10 001e.ffff.fffe default 0.0.0.0   ::        Up     1385


    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:

       Embedded Wireless Controller on Catalyst Access Points
       IOS Software
       IOS XR Software
       Meraki products
       NX-OS Software
       Wireless LAN Controller (WLC) AireOS Software

Indicators of Compromise

  o The Cisco Security Indicators of Compromise Reference Guide lists commonly
    observed IoCs, which can help identify devices that may have been impacted
    by the vulnerability disclosed in this Cisco security advisory.

    Exploitation of this vulnerability could cause a crash of the mobilityd 
    process on an affected device. When a device has experienced a crash of the
    mobilityd process, the following messages may be seen in the crash log
    bundle:

        Feb 15 19:15:43.331: %ID_MANAGER-3-INVALID_ID: Chassis 1 R0/0: mobilityd: bad id in id_get (Out of IDs!) (id: 0x00000000)

Workarounds

  o There are no workarounds that address this vulnerability.

Fixed Software

  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:
    https://www.cisco.com/c/en/us/products/end-user-license-agreement.html

    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
    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.

    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 the resolution of a Cisco TAC support
    case.

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.

Related to This Advisory

  o Cisco Event Response: September 2022 Semiannual Cisco IOS and IOS XE
    Software Security Advisory Bundled Publication

URL

  o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-c9800-mob-dos-342YAc6J

Revision History

  o +----------+---------------------------+----------+--------+--------------+
    | Version  |        Description        | Section  | Status |     Date     |
    +----------+---------------------------+----------+--------+--------------+
    | 1.0      | Initial public release.   | -        | Final  | 2022-SEP-28  |
    +----------+---------------------------+----------+--------+--------------+

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