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Windows 10Operating system · Microsoft

CVE-2018-8343

HIGH · 7.8 CVSS v3.0 Published 2018-08-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
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
An elevation of privilege vulnerability exists in the Network Driver Interface Specification (NDIS) when ndis.sys fails to check the length of a buffer prior to copying memory to it, aka "Windows NDIS Elevation of Privilege Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8342.

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

Elevation of privilege vulnerability in Windows NDIS (Network Driver Interface Specification) where ndis.sys fails to validate buffer length before copying memory, allowing a local attacker to escalate privileges to kernel level.

MitigationApply Microsoft security updates for CVE-2018-8343 via Windows Update or enterprise patch management systems. Prioritize domain controllers and systems with direct network exposure.

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
Windows 10Operating system
Affected:all versions= 1607= 1703= 1709= 1803
Windows 7Operating system
Affected:all versions
Windows 8.1Operating system
Affected:all versions
Windows Rt 8.1Operating system
Affected:all versions
Windows Server 2008Operating system
Affected:all versions= r2
Windows Server 2012Operating system
Affected:all versions= r2
Windows Server 2016Operating system
Affected:all versions= 1709= 1803

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

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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. Check Windows version and build number
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to get the exact Windows version and build. For Windows 10, also run 'winver' to see the build (e.g., 1607, 1703, 1709, 1803).
    Affected if The system runs Windows 10 (any version including 1607, 1703, 1709, 1803), Windows 7, Windows 8.1, Windows RT 8.1, Windows Server 2008 (any including R2), Windows Server 2012 (any including R2), or Windows Server 2016 (any including 1709, 1803).
  2. Verify if August 2018 security update is installed
    Open Control Panel > Programs > View installed updates, or run 'wmic qfe list' command to list installed hotfixes. Look for KB4343887 (Windows 10 version 1803), KB4343886 (Windows 10 version 1709), KB4343885 (Windows 10 version 1703), KB4343884 (Windows 10 version 1607), or KB4346877 (Windows 10 version 1803). For other Windows versions, look for August 2018 Security Updates.
    Affected if The corresponding August 2018 security update for your Windows version is NOT installed.
  3. Check ndis.sys file version
    Navigate to C:\Windows\System32\drivers\ndis.sys, right-click > Properties > Details tab, or run 'powershell (Get-Item C:\Windows\System32\drivers\ndis.sys).VersionInfo' to see the file version.
    Affected if The ndis.sys version is older than the patched version for your Windows build (the patched versions include fixes for the buffer validation vulnerability).
  4. Confirm system is running NDIS driver
    Run 'sc query ndis' or check Device Manager > Network adapters to verify network drivers are loaded. The vulnerability affects ndis.sys specifically.
    Affected if The system has network adapters and NDIS driver (ndis.sys) is loaded and running.

A system is affected if it runs any of the listed Windows versions (Windows 7, 8.1, 10, Server 2008/2012/2016) and does not have the August 2018 security update installed for its specific version.

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 Microsoft security updates for CVE-2018-8343 via Windows Update or enterprise patch management systems. Prioritize domain controllers and systems with direct network exposure.

Fix this in Windows 10 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,780
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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-2018-8343 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