IRONSMITHINTEL
HIGHCVSS8.8
|
Actively Exploited
|CISA KEV|CVE-2023-21674|Auth: low — authenticated user|Reboot: required|Manual only

KB5022282: Windows Server Security Update (January 2023)

Microsoft Windows Advanced Local Procedure Call (ALPC) contains an unspecified vulnerability that allows for privilege escalation.

Published Jan 10, 2023 · 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. Federal agencies are required to remediate by 2023-01-31 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Use After Free (CWE-416) vulnerability in Microsoft Windows. Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability 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:

●Windows Administrators
●Systems Engineers
●IT Security
●Running windows 10 1507: v < 10.0.10240.19685; windows 10 1607: v < 10.0.14393.5648; windows 10 1809: v < 10.0.17763.3887; windows 10 20h2: v < 10.0.19042.2486; windows 10 21h2: v < 10.0.19044.2486; windows 10 22h2: v < 10.0.19045.2486; windows 11 21h2: v < 10.0.22000.1455; windows 11 22h2: v < 10.0.22621.1105; windows rt 8.1: -; windows server 2012: r2; windows server 2016: v < 10.0.14393.5648; windows server 2019: v < 10.0.17763.3887; windows server 2022: v < 10.0.20348.1487
Fixed inKB5022282, KB5022286, KB5022287, KB5022289, KB5022291, KB5022297, KB5022303, KB5022346, KB5022352 (applies to 30 product versions) — build 10.0.10240.19685, 10.0.14393.5648+
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2023-01-10 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2023-01-31.

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 CatalogKB5022282

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB5022282 — https://support.microsoft.com/help/5022282
    1
    KB5022286 — https://support.microsoft.com/help/5022286
    1
    KB5022287 — https://support.microsoft.com/help/5022287
    1
    KB5022289 — https://support.microsoft.com/help/5022289
    1
    KB5022291 — https://support.microsoft.com/help/5022291
    1
    KB5022297 — https://support.microsoft.com/help/5022297
    1
    KB5022303 — https://support.microsoft.com/help/5022303
    1
    KB5022346 — https://support.microsoft.com/help/5022346
    1
    KB5022352 — https://support.microsoft.com/help/5022352

Supersedes: KB5021233, KB5021234, KB5021235, KB5021237, KB5021243, KB5021249, KB5021255, KB5021294

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 20H2 for 32-bit Systems
    1
    Windows 10 Version 20H2 for ARM64-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 8.1 for 32-bit systems
    1
    (…10 more product versions)

Fixed Build Numbers

    1
    10.0.10240.19685
    1
    10.0.14393.5648
    1
    10.0.17763.3887
    1
    10.0.19042.2486
    1
    10.0.19044.2486
    1
    10.0.19045.2486
    1
    10.0.20348.1487
    1
    10.0.22000.1455
    1
    10.0.22621.1105
    1
    6.3.9600.20778

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 KB5022282
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 KB5022282 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022282
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022286
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022287
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022289
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5022291
    1
    (…4 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5022282','KB5022286','KB5022287','KB5022289','KB5022291','KB5022297','KB5022303','KB5022346','KB5022352') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2023-21674
    1
    KB article: https://support.microsoft.com/help/5022282
    1
    KB article: https://support.microsoft.com/help/5022286
    1
    KB article: https://support.microsoft.com/help/5022303
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-21674
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-21674

Discovery Credit

Jan Vojtěšek, Milánek, and Przemek Gmerek with Avast

PowerShell automationComing soon

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

References

↗ CVE-2023-21674↗ MSRC Advisory↗ NVD↗ KBKB5022282