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Windows 10 1809 Windows 10 1809 Security update
Patch Tuesday Zero-day

KB5034768

KB5034768: Cumulative update for Windows 10, version 1809, February 2024. Exploited kernel, SmartScreen and shortcut flaws addressed

In short

The update addresses 38 vulnerabilities, including three exploited flaws in the Windows kernel, SmartScreen and internet shortcut files, plus one critical flaw in Windows PGM.

Does it affect you? Applies to: Devices running Windows 10 Enterprise LTSC 2019, version 1809.

Build
17763.5458
Security
38 fixed · 1 critical · 3 exploited

Microsoft publishes separate notes for this KB for Windows Server.

What changes

Improvements 5 changes

Windows nesting limit

  • The Windows nesting limit can now be set as low as 35 instead of 50.1
    The registry value is HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\USERNestedWindowLimit. The page cautions against changing it unless a kernel stack overflow and recursion in DestroyWindow() cause stop errors.

UEFI Secure Boot

  • UEFI Secure Boot systems can opt to add a renewed signing certificate.2
    Adds a renewed signing certificate to the Secure Boot DB variable; the change is optional.

Windows Kernel Vulnerable Driver Blocklist

  • The vulnerable driver blocklist gets its quarterly update, adding drivers at risk of being used in BYOVD attacks.3
    Updates DriverSiPolicy.p7b with quarterly changes to the Windows Kernel Vulnerable Driver Blocklist.

Active Directory Users & Computers

  • The snap-in uses a stronger certificate mapping by default.4
    Changes the default mapping to X509IssuerSerialNumber instead of the weak x509IssuerSubject mapping.

Servicing stack

  • The component that installs Windows updates receives quality improvements to help devices receive and install updates reliably.5
    Includes the Windows 10 servicing stack update, version 17763.5441.

Fixes 4 changes

Device metadata

For: devices downloading metadata over HTTPS

  • Downloads of device metadata over HTTPS are more secure.6
    Addresses an issue affecting downloads from Windows Metadata and Internet Services (WMIS) over HTTPS.

Windows LAPS

  • You can sign in to a Windows LAPS-managed local account when the Require Smart Card for Interactive Logon policy is set.7
    Addresses the sign-in issue for a local account managed by Windows LAPS under the “Require Smart Card for Interactive Logon” policy.

Windows Management Instrumentation (WMI)

  • The WMI caching issue that changes the time zone to the wrong value is addressed.8
    Addresses a caching issue that causes CurrentTimeZone to change to the wrong value.

Local Security Authority Subsystem Service (LSASS)

For: devices accessing an Active Directory database

  • The issue that might cause LSASS to stop working while accessing the Active Directory database is addressed.9
    Addresses an issue that might cause LSASS to stop working when accessing the Active Directory database.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2024-02-13
Type
Cumulative update
VersionBuildChannel
1809 17763.5458 General availability

Security

38 vulnerabilities fixed
3 exploited 1 critical 36 important 1 moderate
VulnerabilitySeverityCVSS
CVE-2024-21412 Exploited
Internet Shortcut Files Security Feature Bypass Vulnerability
 Important 8.1
CVE-2024-21338 Exploited
Windows Kernel Elevation of Privilege Vulnerability
 Important 7.8
CVE-2024-21351 Exploited
Windows SmartScreen Security Feature Bypass Vulnerability
 Moderate 7.6
CVE-2024-21357
Windows Pragmatic General Multicast (PGM) Remote Code Execution Vulnerability
 Critical 8.1

The table lists the 4 exploited, publicly disclosed or critical vulnerabilities. See all 38 vulnerabilities →

Sources

Updated
Cited passages from Microsoft's official notes (9)
  1. 1. This update addresses an issue that affects the Windows nesting limit. You can now set it to a low of 35 instead of 50. support.microsoft.com
  2. 2. This update affects Unified Extensible Firmware Interface (UEFI) Secure Boot systems. It adds a renewed signing certificate to the Secure Boot DB variable. You can now opt for this change. support.microsoft.com
  3. 3. This update includes quarterly changes to the Windows Kernel Vulnerable Driver Blocklist file, DriverSiPolicy.p7b. It adds to the list of drivers that are at risk for Bring Your Own Vulnerable Driver (BYOVD) attacks. support.microsoft.com
  4. 4. This update changes a setting in Active Directory Users & Computers. By default, the snap-in now uses a strong certificate mapping of X509IssuerSerialNumber. It does not use the weak mapping of x509IssuerSubject. support.microsoft.com
  5. 5. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  6. 6. This update addresses an issue that affects the download of device metadata. Downloads from the Windows Metadata and Internet Services (WMIS) over HTTPS are now more secure. support.microsoft.com
  7. 7. This update addresses an issue that affects a local account. You cannot sign in to an account that Windows LAPS manages. This occurs if you set the "Require Smart Card for Interactive Logon" policy. support.microsoft.com
  8. 8. This update addresses an issue that affects Windows Management Instrumentation (WMI). A caching issue occurs. The issue causes CurrentTimeZone to change to the wrong value. support.microsoft.com
  9. 9. This update addresses an issue that affects the Local Security Authority Subsystem Service (LSASS). It might stop working. This occurs when you access the Active Directory database. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 9 quoted passages · compared with Microsoft's page on Nov 8, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: not passed

A second AI read the text against the sources: correctness 5/5, clarity 4/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake