IRONSMITHINTEL
HIGHCVSS8.1
|
Actively Exploited
|CISA KEV|CVE-2024-21412|Auth: none — unauthenticated|Reboot: required|Manual only

KB5034763: Windows Server Security Update (February 2024)

Microsoft Windows Internet Shortcut Files contains an unspecified vulnerability that allows for a security feature bypass.

Published Feb 13, 2024 · 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. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2024-03-05 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Software Vulnerability (CWE-693) (CWE-693) vulnerability in Microsoft Windows. Internet Shortcut Files 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 1809: v < 10.0.17763.5458; windows 10 21h2: v < 10.0.19044.4046; windows 10 22h2: v < 10.0.19045.4046; windows 11 21h2: v < 10.0.22000.2777; windows 11 22h2: v < 10.0.22621.3155; windows 11 23h2: v < 10.0.22631.3155; windows server 2019: v < 10.0.17763.5458; windows server 2022: v < 10.0.20348.2322; windows server 2022 23h2: v < 10.0.25398.709
Fixed inKB5034763, KB5034765, KB5034766, KB5034768, KB5034769, KB5034770 (applies to 20 product versions) — build 10.0.17763.5458, 10.0.19044.4046+
Real-world incidentsWhat we've seen

CISA confirms this CVE has been used in known ransomware campaigns. Added to the KEV catalog on 2024-02-13; federal agencies required to remediate by 2024-03-05.

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 CatalogKB5034763

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB5034763 — https://support.microsoft.com/help/5034763
    1
    KB5034765 — https://support.microsoft.com/help/5034765
    1
    KB5034766 — https://support.microsoft.com/help/5034766
    1
    KB5034768 — https://support.microsoft.com/help/5034768
    1
    KB5034769 — https://support.microsoft.com/help/5034769
    1
    KB5034770 — https://support.microsoft.com/help/5034770

Supersedes: KB5034121, KB5034122, KB5034123, KB5034127, KB5034129, KB5034130

Affected Products

    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 11 Version 22H2 for ARM64-based Systems
    1
    Windows 11 Version 22H2 for x64-based Systems
    1
    Windows 11 Version 23H2 for ARM64-based Systems
    1
    Windows 11 Version 23H2 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 2019
    1
    Windows Server 2019 (Server Core installation)
    1
    Windows Server 2022
    1
    Windows Server 2022 (Server Core installation)
    1
    Windows Server 2022, 23H2 Edition (Server Core installation)

Fixed Build Numbers

    1
    10.0.17763.5458
    1
    10.0.19044.4046
    1
    10.0.19045.4046
    1
    10.0.20348.2322
    1
    10.0.22000.2777
    1
    10.0.22621.3155
    1
    10.0.22631.3155
    1
    10.0.25398.709

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 KB5034763
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 KB5034763 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5034763
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5034765
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5034766
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5034768
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5034769
    1
    (…1 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5034763','KB5034765','KB5034766','KB5034768','KB5034769','KB5034770') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2024-21412
    1
    KB article: https://support.microsoft.com/help/5034763
    1
    KB article: https://support.microsoft.com/help/5034765
    1
    KB article: https://support.microsoft.com/help/5034766
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2024-21412
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21412

Discovery Credit

Peter Girnus (gothburz) of Trend Micro's Zero Day Initiative with Trend Micro, Dima Lenz and Vlad Stolyarov of Google's Threat Analysis Group, dwbzn with Aura Information Security

PowerShell automationComing soon

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

References

↗ CVE-2024-21412↗ MSRC Advisory↗ NVD↗ KBKB5034763