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Wireless Lan Controller SoftwareOperating system · Cisco

CVE-2018-0235

HIGH · 7.4 CVSS v3.1 Published 2018-05-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
79/100
Remediation priority · High
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 802.11 frame validation functionality of the Cisco Wireless LAN Controller (WLC) could allow an unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of certain 802.11 management information element frames that an affected device receives from wireless clients. An attacker could exploit this vulnerability by sending a malformed 802.11 management frame to an affected device. A successful exploit could allow the attacker to cause the affected device to reload unexpectedly, resulting in a DoS condition. This vulnerability affects only Cisco Wireless LAN Controllers that are running Cisco Mobility Express Release 8.5.103.0. Cisco Bug IDs: CSCvg07024.

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

A vulnerability in the 802.11 frame validation functionality of Cisco Wireless LAN Controllers running Mobility Express Release 8.5.103.0 allows an unauthenticated, adjacent attacker to send malformed 802.11 management information element frames. Due to incomplete input validation, this causes the affected device to unexpectedly reload, resulting in a denial of service condition.

MitigationApply the vendor patch for Cisco Bug ID CSCvg07024 by upgrading to a patched Cisco Mobility Express release. If immediate patching is not feasible, implement network access controls to restrict adjacent attacker proximity to the wireless controller.

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:= 8.6\(1.106\)= 8.6\(1.114\)

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
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/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 Cisco WLC software version
    Run 'show version' or 'show run-config' on the Wireless LAN Controller CLI to display the installed software version and build number
    Affected if The displayed version matches 8.6.1.106 or 8.6.1.114 exactly, or falls within an unpatched range based on these releases
  2. Confirm Mobility Express deployment
    Run 'show mobility' or 'show inventory' on the WLC CLI to verify the controller is running Cisco Mobility Express (ME) image
    Affected if The controller is confirmed to be running a Mobility Express image
  3. Verify 802.11 wireless functionality is enabled
    Run 'show wireless summary' or 'show interface summary' on the WLC CLI to confirm that at least one WLAN or the wireless management interface is active
    Affected if 802.11 management frame processing is enabled (wireless interfaces are up)
  4. Check controller uptime for unexpected reloads
    Run 'show system uptime' or review syslog/console logs for evidence of unexpected reloads, particularly if reloads occur without admin intervention
    Affected if The controller has experienced unexplained reloads, which could indicate exploitation of this vulnerability

The environment is affected only if the Cisco Wireless LAN Controller is running Mobility Express software version exactly 8.6.1.106 or 8.6.1.114, with wireless functionality enabled, and experiencing unexpected reloads from adjacent malicious 802.11 frames.

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 patch for Cisco Bug ID CSCvg07024 by upgrading to a patched Cisco Mobility Express release. If immediate patching is not feasible, implement network access controls to restrict adjacent attacker proximity to the wireless controller.

Fix this in Wireless Lan Controller Software Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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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-2018-0235 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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