IRONSMITHINTEL
HIGHCVSS7.8
|
Actively Exploited
|CISA KEV|CVE-2018-8405|Auth: low — authenticated user|Reboot: required|Manual only

KB4343885: Windows Server Security Update (August 2018)

An elevation of privilege vulnerability exists when the DirectX Graphics Kernel (DXGKRNL) driver improperly handles objects in memory.

Published Aug 15, 2018 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A local attacker, with a low-privilege account, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2022-04-18 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Software Vulnerability (CWE-404) (CWE-404) vulnerability in Microsoft DirectX Graphics Kernel (DXGKRNL). An elevation of privilege vulnerability exists when the DirectX Graphics Kernel (DXGKRNL) driver improperly handles objects in memory, aka "DirectX Graphics Kernel Elevation of Privilege Vulnerability." This affects Windows Server 2012 R2, Windows RT 8.1, Windows Server 2016, Windows 8.1, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8400, CVE-2018-8401, CVE-2018-8406. Exploitation requires local access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running windows 10 1507: -; windows 10 1607: -; windows 10 1703: -; windows 10 1709: -; windows 10 1803: -; windows 8.1: -; windows rt 8.1: -; windows server 1709: -; windows server 1803: -; windows server 2012: r2; windows server 2016: -
Fixed inKB4343885, KB4343887, KB4343888, KB4343892, KB4343897, KB4343898, KB4343909 (applies to 19 product versions)
Real-world incidentsWhat we've seen

CISA confirms this CVE has been used in known ransomware campaigns. Added to the KEV catalog on 2022-03-28; federal agencies required to remediate by 2022-04-18.

How to patch

Manual download

For air-gapped servers or out-of-band deployment. Microsoft Update Catalog returns every OS-version variant of this update.

↗ Microsoft Update CatalogKB4343885

Manual remediation steps

Apply the Microsoft Security Update

Microsoft has released an official security update that fixes this vulnerability.

Required KB Updates

    1
    KB4343885 — https://support.microsoft.com/help/4343885
    1
    KB4343887 — https://support.microsoft.com/help/4343887
    1
    KB4343888 — https://support.microsoft.com/help/4343888
    1
    KB4343892 — https://support.microsoft.com/help/4343892
    1
    KB4343897 — https://support.microsoft.com/help/4343897
    1
    KB4343898 — https://support.microsoft.com/help/4343898
    1
    KB4343909 — https://support.microsoft.com/help/4343909

Supersedes: KB4338814, KB4338815, KB4338819, KB4338825, KB4338826, KB4338829

Affected Products

    1
    Windows 10 Version 1607 for 32-bit Systems
    1
    Windows 10 Version 1607 for x64-based Systems
    1
    Windows 10 Version 1703 for 32-bit Systems
    1
    Windows 10 Version 1703 for x64-based Systems
    1
    Windows 10 Version 1709 for 32-bit Systems
    1
    Windows 10 Version 1709 for x64-based Systems
    1
    Windows 10 Version 1803 for 32-bit Systems
    1
    Windows 10 Version 1803 for x64-based Systems
    1
    Windows 10 for 32-bit Systems
    1
    Windows 10 for x64-based Systems
    1
    Windows 8.1 for 32-bit systems
    1
    Windows 8.1 for x64-based systems
    1
    Windows RT 8.1
    1
    Windows Server 2012 R2
    1
    Windows Server 2012 R2 (Server Core installation)
    1
    Windows Server 2016
    1
    Windows Server 2016 (Server Core installation)
    1
    Windows Server, version 1709 (Server Core Installation)
    1
    Windows Server, version 1803 (Server Core Installation)

Installation Methods

Windows Update (recommended)

1
Settings → Windows Update → Check for updates
2
The security update is offered if your system is in scope
3
Restart when prompted — a reboot IS required to complete the install

Microsoft Update Catalog (manual download)

1
Open https://catalog.update.microsoft.com
2
Search for KB4343885
3
Download the package matching your OS architecture and Windows build
4
Run the .msu installer with administrator privileges
5
Restart when prompted

WSUS / SCCM / Intune

Approve KB4343885 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4343885
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4343887
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4343888
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4343892
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4343897
    1
    (…2 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB4343885','KB4343887','KB4343888','KB4343892','KB4343897','KB4343898','KB4343909') }

References

    1
    Microsoft Security Response Center: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8405
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2018-8405
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-8405

Discovery Credit

Communications Security Establishment, CSE, ChenNan and RanchoIce of Tencent ZhanluLab working with Trend Micro's Zero Day Initiative

PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2018-8405↗ MSRC Advisory↗ NVD↗ KBKB4343885