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Ios XeOperating system · Cisco

CVE-2020-3486

MEDIUM · 6.5 CVSS v3.1 Published 2020-09-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
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
Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition of an affected device. These vulnerabilities are due to insufficient validation of CAPWAP packets. An attacker could exploit these vulnerabilities by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition on the affected device.

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 the CAPWAP (Control and Provisioning of Wireless Access Points) protocol processing component of Cisco IOS XE Software running on Cisco Catalyst 9800 Series Wireless Controllers. The root cause is insufficient validation of incoming CAPWAP packets, allowing an unauthenticated adjacent attacker to send malformed packets that cause the affected device to crash and reload, resulting in denial of service.

MitigationApply the vendor-supplied patch for Cisco IOS XE Software when available. Prior to patching, consider network segmentation to limit adjacent network access to CAPWAP-enabled interfaces.

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:all versions

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/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. Confirm device is a Cisco Catalyst 9800 Series Wireless Controller
    Run 'show version' and look for 'Catalyst 9800' in the hardware description or 'C9800' in the model name
    Affected if Device is NOT a Catalyst 9800 Series Wireless Controller - this vulnerability only affects that product line
  2. Verify the IOS XE software version
    Run 'show version' and check the 'IOS XE Software' or 'Version' line to identify the installed IOS XE release
    Affected if Running any version of Cisco IOS XE on an affected Catalyst 9800 controller - the advisory states all versions are affected
  3. Confirm CAPWAP protocol is enabled
    Run 'show capwap summary' or 'show wireless ap capwap status' to check if CAPWAP is active on the controller
    Affected if CAPWAP is enabled and accepting connections - the vulnerability lies in CAPWAP packet validation, so CAPWAP must be active for exploitation
  4. Check for wireless APs joined to the controller
    Run 'show ap join summary' or 'show wireless ap summary' to see if any APs are connected via CAPWAP
    Affected if Any APs are joined and communicating via CAPWAP - this indicates active CAPWAP traffic that could trigger the flaw

A user is affected if they are running Cisco IOS XE on a Catalyst 9800 Series Wireless Controller with CAPWAP enabled and wireless APs actively joined, regardless of IOS XE version since all versions are vulnerable.

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-supplied patch for Cisco IOS XE Software when available. Prior to patching, consider network segmentation to limit adjacent network access to CAPWAP-enabled interfaces.

Fix this in Ios Xe Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2020-3486 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data