IRONSMITHINTEL
HIGHCVSS8.4
|
Actively Exploited
|CISA KEV|CVE-2023-29360|Auth: none — unauthenticated|Reboot: required|Manual only

KB5027215: Windows Server Security Update (June 2023)

Microsoft Streaming Service contains an untrusted pointer dereference vulnerability that allows for privilege escalation, enabling a local attacker to gain SYSTEM privileges.

Published Jun 14, 2023 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A local attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2024-03-21 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Software Vulnerability (CWE-822) (CWE-822) vulnerability in Microsoft Streaming Service. Exploitation requires local access, low attack complexity, no authentication required, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running windows 10 1607: v < 10.0.14393.5989; windows 10 1809: v < 10.0.17763.4499; windows 10 21h2: v < 10.0.19044.3086; windows 10 22h2: v < 10.0.19045.3086; windows 11 21h2: v < 10.0.22000.2057; windows 11 22h2: v < 10.0.22621.1848; windows server 2016: v < 10.0.14393.5989; windows server 2019: v < 10.0.17763.4499; windows server 2022: v < 10.0.20348.1784
Fixed inKB5027215, KB5027219, KB5027222, KB5027223, KB5027225, KB5027231, KB5027319 (applies to 21 product versions) — build 10.0.14393.5989, 10.0.17763.4499+
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2024-02-29 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2024-03-21.

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 CatalogKB5027215

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB5027215 — https://support.microsoft.com/help/5027215
    1
    KB5027219 — https://support.microsoft.com/help/5027219
    1
    KB5027222 — https://support.microsoft.com/help/5027222
    1
    KB5027223 — https://support.microsoft.com/help/5027223
    1
    KB5027225 — https://support.microsoft.com/help/5027225
    1
    KB5027231 — https://support.microsoft.com/help/5027231
    1
    KB5027319 — https://support.microsoft.com/help/5027319

Supersedes: KB5026361, KB5026362, KB5026363, KB5026368, KB5026370, KB5026372

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 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 2016
    1
    Windows Server 2016 (Server Core installation)
    1
    Windows Server 2019
    1
    Windows Server 2019 (Server Core installation)
    1
    Windows Server 2022
    1
    (…1 more product versions)

Fixed Build Numbers

    1
    10.0.14393.5989
    1
    10.0.17763.4499
    1
    10.0.19044.3086
    1
    10.0.19045.3086
    1
    10.0.20348.1784
    1
    10.0.20348.1787
    1
    10.0.22000.2057
    1
    10.0.22621.1848

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 KB5027215
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 KB5027215 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5027215
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5027219
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5027222
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5027223
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5027225
    1
    (…2 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5027215','KB5027219','KB5027222','KB5027223','KB5027225','KB5027231','KB5027319') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-29360
    1
    KB article: https://support.microsoft.com/help/5027215
    1
    KB article: https://support.microsoft.com/help/5027219
    1
    KB article: https://support.microsoft.com/help/5027222
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2023-29360
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-29360

Discovery Credit

Thomas Imbert (@masthoon) from Synacktiv (@Synacktiv) Working with Trend Micro Zero Day Initiative

PowerShell automationComing soon

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

References

↗ CVE-2023-29360↗ MSRC Advisory↗ NVD↗ KBKB5027215