dbcve.org
Wireless Lan Controller SoftwareOperating system · Cisco

CVE-2018-0443

HIGH · 7.5 CVSS v3.1 Published 2018-10-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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 component of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper input validation on fields within CAPWAP Discovery Request packets by the affected device. An attacker could exploit this vulnerability by sending malicious CAPWAP Discovery Request packets to the Cisco WLC Software. A successful exploit could allow the attacker to cause the Cisco WLC Software to disconnect associated access points (APs). While the APs disconnect and reconnect, service will be unavailable for a brief period of time, 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

The vulnerability exists in the CAPWAP (Control and Provisioning of Wireless Access Points) protocol component of Cisco Wireless LAN Controller Software. It stems from improper input validation on fields within CAPWAP Discovery Request packets. An unauthenticated remote attacker can send malicious CAPWAP Discovery Request packets to the WLC, triggering a DoS condition that disconnects associated access points.

MitigationApply the Cisco software update/patch for CVE-2018-0443 to the Wireless LAN Controller. In the interim, consider network segmentation or ACLs to restrict CAPWAP traffic to trusted management 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
Wireless Lan Controller SoftwareOperating system
Affected:= 8.2\(151.0\)

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
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/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 the device is a Cisco Wireless LAN Controller
    Check the device model via 'show inventory' or the physical label. This vulnerability affects only Cisco WLC platforms, not other network devices.
    Affected if The device is not a Cisco Wireless LAN Controller (models like 5508, 5520, 8540, etc.)
  2. Identify the installed Cisco WLC software version
    Run 'show version' on the WLC CLI or check via the web interface under Monitor > Controller > General. Look for the software version number.
    Affected if The installed version is exactly 8.2(151.0)
  3. Verify CAPWAP protocol is active on the controller
    Run 'show capwap summary' or 'show ap summary' to confirm CAPWAP is enabled and access points are connected. CAPWAP (UDP 5246/5247) is required for this vulnerability to be exploitable.
    Affected if CAPWAP is disabled and no APs are connected (unlikely on a functional WLC)
  4. Check if the WLC management interface is exposed to untrusted networks
    Review the WLC management interface configuration via 'show interface summary' and check ACLs or firewall rules that may limit CAPWAP access. The vulnerability is exploitable via the management IP receiving CAPWAP Discovery Requests.
    Affected if The WLC management IP is reachable from untrusted/networked segments without ACL filtering on UDP 5246/5247

You are affected if the device is a Cisco Wireless LAN Controller running exactly version 8.2(151.0) and its management interface with CAPWAP (UDP 5246/5247) is accessible to network attackers.

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 Cisco software update/patch for CVE-2018-0443 to the Wireless LAN Controller. In the interim, consider network segmentation or ACLs to restrict CAPWAP traffic to trusted management interfaces.

Fix this in Wireless Lan Controller Software Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,720
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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-2018-0443 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
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  • Version or environment caveats, and links to real fixes
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