IRONSMITHINTEL
HIGHCVSS7.5
|
Actively Exploited
|CISA KEV|CVE-2018-8174|Auth: none — unauthenticated|Reboot: required|Manual only

KB4103712: Windows Server Security Update (May 2018)

A remote code execution vulnerability exists in the way that the VBScript engine handles objects in memory, aka "Windows VBScript Engine Remote Code Execution"

Published May 9, 2018 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, 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 2022-08-15 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Out-of-bounds Write (CWE-787) vulnerability in Microsoft Windows. A remote code execution vulnerability exists in the way that the VBScript engine handles objects in memory, aka "Windows VBScript Engine Remote Code Execution Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers. Exploitation requires remote network access, higher attack complexity, no authentication required, and user interaction required.

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Phishing link

→

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Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●Windows Administrators
●Systems Engineers
●IT Security
●Running windows 10 1607: -; windows 10 1703: -; windows 10 1709: -; windows 10 1803: -; windows 7: -; windows 8.1: -; windows rt 8.1: -; windows server 2008: -, r2; windows server 2012: -, r2; windows server 2016: -
Fixed inKB4103712, KB4103715, KB4103716, KB4103718, KB4103721, KB4103723, KB4103725, KB4103726, KB4103727, KB4103730, KB4103731, KB4134651 (applies to 31 product versions)
Real-world incidentsWhat we've seen

Used in known ransomware campaigns. Threat-research write-up: https://blog.0patch.com/2018/05/a-single-instruction-micropatch-for.html

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 CatalogKB4103712

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB4103712 — https://support.microsoft.com/help/4103712
    1
    KB4103715 — https://support.microsoft.com/help/4103715
    1
    KB4103716 — https://support.microsoft.com/help/4103716
    1
    KB4103718 — https://support.microsoft.com/help/4103718
    1
    KB4103721 — https://support.microsoft.com/help/4103721
    1
    KB4103723 — https://support.microsoft.com/help/4103723
    1
    KB4103725 — https://support.microsoft.com/help/4103725
    1
    KB4103726 — https://support.microsoft.com/help/4103726
    1
    KB4103727 — https://support.microsoft.com/help/4103727
    1
    KB4103730 — https://support.microsoft.com/help/4103730
    1
    KB4103731 — https://support.microsoft.com/help/4103731
    1
    KB4134651 — https://support.microsoft.com/help/4134651

Supersedes: KB4018556, KB4093107, KB4093111, KB4093112, KB4093114, KB4093118, KB4093119, KB4093123

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 7 for 32-bit Systems Service Pack 1
    1
    Windows 7 for x64-based Systems Service Pack 1
    1
    Windows 8.1 for 32-bit systems
    1
    Windows 8.1 for x64-based systems
    1
    Windows RT 8.1
    1
    Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1
    1
    Windows Server 2008 R2 for x64-based Systems Service Pack 1
    1
    Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
    1
    Windows Server 2008 for 32-bit Systems Service Pack 2
    1
    Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
    1
    (…11 more product versions)

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 KB4103712
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 KB4103712 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4103712
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4103715
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4103716
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4103718
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4103721
    1
    (…7 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB4103712','KB4103715','KB4103716','KB4103718','KB4103721','KB4103723','KB4103725','KB4103726','KB4103727','KB4103730','KB4103731','KB4134651') }

References

    1
    Microsoft Security Response Center: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8174
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2018-8174
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-8174

Discovery Credit

Dan Lutas of Bitdefender, Ding Maoyin of Qihoo 360 Core Security, Anton Ivanov of Kaspersky Lab, Song Shenlei of Qihoo 360 Core Security, Anonymous working with Trend Micro's Zero Day Initiative, Simon Zuckerbraun working with Trend Micro's Zero Day Initiative, Yang Kang of Qihoo 360 Core Security, Jinquan of Qihoo 360 Core Security, Vladislav Stolyarov of Kaspersky Lab

PowerShell automationComing soon

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

References

↗ CVE-2018-8174↗ MSRC Advisory↗ NVD↗ KBKB4103712