IRONSMITHINTEL
MEDIUMCVSS5.4
|
Actively Exploited
|CISA KEV|CVE-2023-36584|Auth: none — unauthenticated|Reboot: required|Manual only

KB5031354: Windows Server Security Update (October 2023)

Microsoft Windows Mark of the Web (MOTW) contains a security feature bypass vulnerability resulting in a limited loss of integrity and availability of security features.

Published Oct 10, 2023 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve partial data exposure, partial data tampering, partial service disruption. Federal agencies are required to remediate by 2023-12-07 under CISA BOD 22-01.

How the attack worksNo clicks needed

This vulnerability affects Microsoft Windows. Windows Mark of the Web Security Feature Bypass Vulnerability Exploitation requires remote network access, low attack complexity, no authentication required, and user interaction required.

📧

Phishing link

→

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●Windows Administrators
●Systems Engineers
●IT Security
●Running windows 10 1507: v < 10.0.10240.20232; windows 10 1809: v < 10.0.17763.4974; windows 10 21h1: v < 10.0.19041.3570; windows 10 22h2: v < 10.0.19041.3570; windows 11 21h2: v < 10.0.22000.2538; windows 11 22h2: v < 10.0.22621.2428; windows server 2008: -, r2; windows server 2012: -, r2; windows server 2016: v < 10.0.14393.6351; windows server 2019: v < 10.0.17763.4974; windows server 2022: v < 10.0.20348.2031
Fixed inKB5031354, KB5031356, KB5031358, KB5031361, KB5031362, KB5031364, KB5031377, KB5031407, KB5031408, KB5031411, KB5031416, KB5031419, KB5031427, KB5031441, KB5031442 (applies to 33 product versions) — build 10.0.10240.20232, 10.0.14393.6351+
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2023-11-16 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2023-12-07.

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 CatalogKB5031354

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB5031354 — https://support.microsoft.com/help/5031354
    1
    KB5031356 — https://support.microsoft.com/help/5031356
    1
    KB5031358 — https://support.microsoft.com/help/5031358
    1
    KB5031361 — https://support.microsoft.com/help/5031361
    1
    KB5031362 — https://support.microsoft.com/help/5031362
    1
    KB5031364 — https://support.microsoft.com/help/5031364
    1
    KB5031377 — https://support.microsoft.com/help/5031377
    1
    KB5031407 — https://support.microsoft.com/help/5031407
    1
    KB5031408 — https://support.microsoft.com/help/5031408
    1
    KB5031411 — https://support.microsoft.com/help/5031411
    1
    KB5031416 — https://support.microsoft.com/help/5031416
    1
    KB5031419 — https://support.microsoft.com/help/5031419
    1
    KB5031427 — https://support.microsoft.com/help/5031427
    1
    KB5031441 — https://support.microsoft.com/help/5031441
    1
    KB5031442 — https://support.microsoft.com/help/5031442

Supersedes: KB5030211, KB5030213, KB5030214, KB5030216, KB5030217, KB5030219, KB5030220, KB5030265, KB5030269, KB5030271, KB5030278

Affected Products

    1
    Windows 10 Version 1607 for 32-bit Systems
    1
    Windows 10 Version 1607 for x64-based Systems
    1
    Windows 10 Version 1809 for 32-bit Systems
    1
    Windows 10 Version 1809 for ARM64-based Systems
    1
    Windows 10 Version 1809 for x64-based Systems
    1
    Windows 10 Version 21H2 for 32-bit Systems
    1
    Windows 10 Version 21H2 for ARM64-based Systems
    1
    Windows 10 Version 21H2 for x64-based Systems
    1
    Windows 10 Version 22H2 for 32-bit Systems
    1
    Windows 10 Version 22H2 for ARM64-based Systems
    1
    Windows 10 Version 22H2 for x64-based Systems
    1
    Windows 10 for 32-bit Systems
    1
    Windows 10 for x64-based Systems
    1
    Windows 11 Version 22H2 for ARM64-based Systems
    1
    Windows 11 Version 22H2 for x64-based Systems
    1
    Windows 11 version 21H2 for ARM64-based Systems
    1
    Windows 11 version 21H2 for x64-based Systems
    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
    (…13 more product versions)

Fixed Build Numbers

    1
    10.0.10240.20232
    1
    10.0.14393.6351
    1
    10.0.17763.4974
    1
    10.0.19041.3570
    1
    10.0.19045.3570
    1
    10.0.20348.2031
    1
    10.0.22000.2538
    1
    10.0.22621.2428
    1
    6.0.6003.22317
    1
    6.1.7601.26769
    1
    (…2 more builds)

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 KB5031354
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 KB5031354 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5031354
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5031356
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5031358
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5031361
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5031362
    1
    (…10 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5031354','KB5031356','KB5031358','KB5031361','KB5031362','KB5031364','KB5031377','KB5031407','KB5031408','KB5031411','KB5031416','KB5031419','KB5031427','KB5031441','KB5031442') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36584
    1
    KB article: http://support.microsoft.com/help/5031364
    1
    KB article: https://support.microsoft.com/help/5031354
    1
    KB article: https://support.microsoft.com/help/5031356
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-36584
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36584

Discovery Credit

Eli Birkan, Dan Yashnik, and Bar Lahav with Palo Alto Networks

PowerShell automationComing soon

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

References

↗ CVE-2023-36584↗ MSRC Advisory↗ NVD↗ KBKB5031354