dbcve.org
Wireless Lan Controller SoftwareOperating system · Cisco

CVE-2018-0420

MEDIUM · 6.5 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 →
71/100
Remediation priority · Elevated
Remotely reachable 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 web-based interface of Cisco Wireless LAN Controller Software could allow an authenticated, remote attacker to view sensitive information. The issue is due to improper sanitization of user-supplied input in HTTP request parameters that describe filenames and pathnames. An attacker could exploit this vulnerability by using directory traversal techniques to submit a path to a desired file location. A successful exploit could allow the attacker to view system files on the targeted device, which may contain sensitive information.

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 directory traversal vulnerability in Cisco Wireless LAN Controller Software's web-based interface allows authenticated remote attackers to access arbitrary system files by manipulating HTTP request parameters containing file paths. The vulnerability stems from improper input sanitization, enabling path traversal sequences like ../ to escape the intended web root directory.

MitigationApply the vendor-supplied patch for CVE-2018-0420. If patching is immediately unavailable, restrict web interface access to trusted IPs only and audit for any unauthorized access. Implement input validation filters on the web server to reject path traversal sequences in filename/path parameters.

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

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 Wireless LAN Controller
    Run 'show version' on the device CLI or check SNMP sysDescr. Look for 'Cisco Wireless LAN Controller' in the device identification.
    Affected if The device is not a Cisco Wireless LAN Controller, then it is not affected by this specific CVE.
  2. Check installed software version
    Execute 'show version' in the controller CLI and locate the software version string. Verify if it equals exactly 8.2(151.0).
    Affected if The version is 8.2(151.0) exactly - this is the only affected version for this CVE.
  3. Verify web interface is enabled
    Check if the web-based management interface is active by reviewing 'show run' output for 'http server' or 'secure-webui' commands, or attempt to access the HTTP/HTTPS management port (typically ports 80 or 443) from a permitted network.
    Affected if The web interface is disabled or inaccessible, the path traversal vulnerability cannot be exploited remotely.
  4. Confirm web interface authentication status
    Review user accounts configured on the controller via 'show run' | include 'username' or check local authentication server settings. Verify whether valid credentials exist for the web interface.
    Affected if The web interface requires authentication, and an attacker needs valid credentials to exploit this directory traversal flaw.

You are affected only if the device is a Cisco Wireless LAN Controller running exactly version 8.2(151.0) with the web-based management interface enabled and accessible using valid credentials.

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 CVE-2018-0420. If patching is immediately unavailable, restrict web interface access to trusted IPs only and audit for any unauthorized access. Implement input validation filters on the web server to reject path traversal sequences in filename/path parameters.

Fix this in Wireless Lan Controller Software Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2018-0420 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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