dbcve.org
Ios XeOperating system · Cisco

CVE-2022-20682

HIGH · 8.6 CVSS v3.1 Published 2022-04-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of 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 inadequate input validation of incoming CAPWAP packets encapsulating multicast DNS (mDNS) queries. An attacker could exploit this vulnerability by connecting to a wireless network and sending a crafted mDNS query, which would flow through and be processed by the wireless controller. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This vulnerability exists in Cisco IOS XE Wireless Controller Software for Catalyst 9000 Family due to insufficient input validation of CAPWAP protocol packets that encapsulate multicast DNS (mDNS) queries. An unauthenticated attacker on the wireless network can send a crafted mDNS query that triggers improper handling, causing the affected device to crash and reload, resulting in denial of service.

MitigationApply the vendor-provided Cisco security patch for this vulnerability. Until patched, consider network segmentation to limit wireless network access and monitor for unusual patterns of mDNS traffic.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Ios XeOperating system
Affected:= 3.15.1xbs= 3.15.2xbs= 16.11.1= 16.11.1a= 16.11.1b= 16.11.1c= 16.11.1s= 16.11.2= 16.12.1= 16.12.1a= 16.12.1c= 16.12.1s

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the device and software version
    Execute 'show version' on the device CLI and locate the IOS XE version string (e.g., 16.11.1s, 16.12.1)
    Affected if The displayed version matches one of the affected versions: 3.15.1xbs, 3.15.2xbs, 16.11.1, 16.11.1a, 16.11.1b, 16.11.1c, 16.11.1s, 16.11.2, 16.12.1, 16.12.1a, 16.12.1c, or 16.12.1s
  2. Confirm the device is running Wireless Controller software
    Execute 'show controllers | include Wireless' or check 'show inventory' for Catalyst 9000 family wireless controller modules
    Affected if The device is a Cisco Catalyst 9000 series running IOS XE with Wireless Controller functionality enabled
  3. Verify mDNS gateway feature is configured
    Execute 'show mdns gateway' or 'show running-config | include mdns' to check if mDNS service is enabled on the wireless controller
    Affected if mDNS gateway is enabled, as the vulnerability is triggered through specially crafted CAPWAP-encapsulated mDNS queries

A device is affected if it runs Cisco IOS XE Wireless Controller on Catalyst 9000 family with a version matching the affected 16.x or 3.15.x ranges and has mDNS functionality enabled, allowing an unauthenticated wireless attacker to crash the device via crafted mDNS queries.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-provided Cisco security patch for this vulnerability. Until patched, consider network segmentation to limit wireless network access and monitor for unusual patterns of mDNS traffic.

Fix this in Ios Xe Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-20682 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data