IRONSMITHINTEL
HIGHCVSS7.8
|
Actively Exploited
|CISA KEV|CVE-2020-0638|Auth: low — authenticated user|Reboot: required|Manual only

KB4528760: Windows Server Security Update (January 2020)

Microsoft Update Notification Manager contains an unspecified vulnerability that allows for privilege escalation.

Published Jan 14, 2020 · 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. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2022-06-13 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Software Vulnerability (CWE-59) (CWE-59) vulnerability in Microsoft Update Notification Manager. An elevation of privilege vulnerability exists in the way the Update Notification Manager handles files.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Update Notification Manager 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:

●IT Security
●Running windows 10 1709: -; windows 10 1803: -; windows 10 1809: -; windows 10 1903: -; windows 10 1909: -; windows server 1803: -; windows server 1903: -; windows server 1909: -; windows server 2019: -
Fixed inKB4528760, KB4534273, KB4534276, KB4534293 (applies to 20 product versions)
Real-world incidentsWhat we've seen

CISA confirms this CVE has been used in known ransomware campaigns. Added to the KEV catalog on 2022-05-23; 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 CatalogKB4528760

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB4528760 — https://support.microsoft.com/help/4528760
    1
    KB4534273 — https://support.microsoft.com/help/4534273
    1
    KB4534276 — https://support.microsoft.com/help/4534276
    1
    KB4534293 — https://support.microsoft.com/help/4534293

Supersedes: KB4530684, KB4530714, KB4530715, KB4530717

Affected Products

    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 Version 1909 for 32-bit Systems
    1
    Windows 10 Version 1909 for ARM64-based Systems
    1
    Windows 10 Version 1909 for x64-based Systems
    1
    Windows Server 2019
    1
    Windows Server 2019 (Server Core installation)
    1
    Windows Server, version 1803 (Server Core Installation)
    1
    Windows Server, version 1903 (Server Core installation)
    1
    Windows Server, version 1909 (Server Core installation)

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 KB4528760
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 KB4528760 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4528760
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4534273
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4534276
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4534293

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB4528760','KB4534273','KB4534276','KB4534293') }

References

    1
    Microsoft Security Response Center: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0638
    1
    KB article: https://support.microsoft.com/help/4534273
    1
    KB article: https://support.microsoft.com/help/4534276
    1
    KB article: https://support.microsoft.com/help/4534293
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2020-0638
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0638

Discovery Credit

Zhiniang Peng (@edwardzpeng) of Qihoo 360 Core Security and Jiadong Lu

PowerShell automationComing soon

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

References

↗ CVE-2020-0638↗ MSRC Advisory↗ NVD↗ KBKB4528760