IRONSMITHINTEL
HIGHCVSS7.8
|
Actively Exploited
|CISA KEV|CVE-2019-0880|Auth: low — authenticated user|Reboot: required|Manual only

KB4507435: Windows Server Security Update (July 2019)

A local elevation of privilege vulnerability exists in how splwow64.exe handles certain calls. An attacker who successfully exploited the vulnerability could elevate privileges on an affected system from low-integrity to medium-integrity.

Published Jul 15, 2019 · 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 2022-06-13 under CISA BOD 22-01.

How the attack worksNo clicks needed

This vulnerability affects Microsoft Windows. A local elevation of privilege vulnerability exists in how splwow64.exe handles certain calls, aka 'Microsoft splwow64 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: -; windows 10 1607: -; windows 10 1703: -; windows 10 1709: -; windows 10 1803: -; windows 10 1809: -; windows 10 1903: -; windows 8.1: -; windows rt 8.1: -; windows server 1903: -; windows server 2012: -, r2; windows server 2016: -; windows server 2019: -
Fixed inKB4507435, KB4507448, KB4507450, KB4507453, KB4507455, KB4507457, KB4507458, KB4507460, KB4507462, KB4507464, KB4507469 (applies to 31 product versions)
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2022-05-23 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2022-06-13.

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 CatalogKB4507435

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB4507435 — https://support.microsoft.com/help/4507435
    1
    KB4507448 — https://support.microsoft.com/help/4507448
    1
    KB4507450 — https://support.microsoft.com/help/4507450
    1
    KB4507453 — https://support.microsoft.com/help/4507453
    1
    KB4507455 — https://support.microsoft.com/help/4507455
    1
    KB4507457 — https://support.microsoft.com/help/4507457
    1
    KB4507458 — https://support.microsoft.com/help/4507458
    1
    KB4507460 — https://support.microsoft.com/help/4507460
    1
    KB4507462 — https://support.microsoft.com/help/4507462
    1
    KB4507464 — https://support.microsoft.com/help/4507464
    1
    KB4507469 — https://support.microsoft.com/help/4507469

Supersedes: KB4503267, KB4503276, KB4503279, KB4503284, KB4503285, KB4503286, KB4503291, KB4503293, KB4503327

Affected Products

    1
    Windows 10 Version 1607 for 32-bit Systems
    1
    Windows 10 Version 1607 for x64-based Systems
    1
    Windows 10 Version 1703 for 32-bit Systems
    1
    Windows 10 Version 1703 for x64-based Systems
    1
    Windows 10 Version 1709 for 32-bit Systems
    1
    Windows 10 Version 1709 for ARM64-based Systems
    1
    Windows 10 Version 1709 for x64-based Systems
    1
    Windows 10 Version 1803 for 32-bit Systems
    1
    Windows 10 Version 1803 for ARM64-based Systems
    1
    Windows 10 Version 1803 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 1903 for 32-bit Systems
    1
    Windows 10 Version 1903 for ARM64-based Systems
    1
    Windows 10 Version 1903 for x64-based Systems
    1
    Windows 10 for 32-bit Systems
    1
    Windows 10 for x64-based Systems
    1
    Windows 8.1 for 32-bit systems
    1
    Windows 8.1 for x64-based systems
    1
    (…11 more product versions)

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 KB4507435
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 KB4507435 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4507435
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4507448
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4507450
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4507453
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4507455
    1
    (…6 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB4507435','KB4507448','KB4507450','KB4507453','KB4507455','KB4507457','KB4507458','KB4507460','KB4507462','KB4507464','KB4507469') }

References

    1
    Microsoft Security Response Center: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0880
    1
    KB article: https://support.microsoft.com/help/4507435
    1
    KB article: https://support.microsoft.com/help/4507448
    1
    KB article: https://support.microsoft.com/help/4507450
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2019-0880
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-0880

Discovery Credit

Gene Yoo of Resecurity, Inc.

PowerShell automationComing soon

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

References

↗ CVE-2019-0880↗ MSRC Advisory↗ NVD↗ KBKB4507435