IRONSMITHINTEL
HIGHCVSS7.8
|
Actively Exploited
|CISA KEV|CVE-2023-36802|Auth: low — authenticated user|Reboot: required|Manual only

KB5030211: Windows Server Security Update (September 2023)

Microsoft Streaming Service Proxy contains an unspecified vulnerability that allows for privilege escalation.

Published Sep 12, 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 2023-10-03 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Use After Free (CWE-416) vulnerability in Microsoft Streaming Service Proxy. 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:

●IT Security
●Running windows 10 1809: v < 10.0.17763.4851; windows 10 21h2: v < 10.0.19044.3448; windows 10 22h2: v < 10.0.19045.3448; windows 11 21h2: v < 10.0.22000.2416; windows 11 22h2: v < 10.0.22621.2275; windows server 2019: v < 10.0.17763.4851; windows server 2022: v < 10.0.20348.1970
Fixed inKB5030211, KB5030214, KB5030216, KB5030217, KB5030219, KB5030325 (applies to 17 product versions) — build 10.0.17763.4851, 10.0.19044.3448+
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2023-09-12 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2023-10-03.

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 CatalogKB5030211

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB5030211 — https://support.microsoft.com/help/5030211
    1
    KB5030214 — https://support.microsoft.com/help/5030214
    1
    KB5030216 — https://support.microsoft.com/help/5030216
    1
    KB5030217 — https://support.microsoft.com/help/5030217
    1
    KB5030219 — https://support.microsoft.com/help/5030219
    1
    KB5030325 — https://support.microsoft.com/help/5030325

Supersedes: KB5029244, KB5029247, KB5029250, KB5029253, KB5029263

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 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)

Fixed Build Numbers

    1
    10.0.17763.4851
    1
    10.0.19044.3448
    1
    10.0.19045.3448
    1
    10.0.20348.1964
    1
    10.0.20348.1970
    1
    10.0.22000.2416
    1
    10.0.22621.2283

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 KB5030211
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 KB5030211 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5030211
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5030214
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5030216
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5030217
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5030219
    1
    (…1 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5030211','KB5030214','KB5030216','KB5030217','KB5030219','KB5030325') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36802
    1
    KB article: https://support.microsoft.com/help/5030211
    1
    KB article: https://support.microsoft.com/help/5030214
    1
    KB article: https://support.microsoft.com/help/5030216
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-36802
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36802

Discovery Credit

Microsoft Security Response Center, Microsoft Threat Intelligence, Guanghui Xia(@ze0r) with Hebei HuaCe, Valentina Palmiotti with IBM X-Force, Quan Jin(@jq0904) & ze0r with DBAPPSecurity WeBin Lab

PowerShell automationComing soon

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

References

↗ CVE-2023-36802↗ MSRC Advisory↗ NVD↗ KBKB5030211