IRONSMITHINTEL
HIGHCVSS8.8
|
Actively Exploited
|CISA KEV|CVE-2019-0541|Auth: none — unauthenticated|Reboot: required|Manual only

KB2553332: Windows Server Security Update (January 2019)

Microsoft MSHTML engine contains an improper input validation vulnerability that allows for remote code execution vulnerability.

Published Jan 8, 2019 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote 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 2022-05-03 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Command Injection (CWE-77) vulnerability in Microsoft MSHTML. A remote code execution vulnerability exists in the way that the MSHTML engine inproperly validates input, aka "MSHTML Engine Remote Code Execution Vulnerability." This affects Microsoft Office, Microsoft Office Word Viewer, Internet Explorer 9, Internet Explorer 11, Microsoft Excel Viewer, Internet Explorer 10, Office 365 ProPlus. Exploitation requires remote network access, low attack complexity, no authentication required, and user interaction required.

📧

Phishing link

→

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running internet explorer: 11, 9, 10; excel viewer: 2007; office: 2010, 2013, 2016, 2019; office 365 proplus: -; office word viewer: -
Fixed inKB2553332, KB2596760, KB3172522, KB4022162, KB4462112, KB4480116, KB4480961, KB4480962, KB4480963, KB4480965, KB4480966, KB4480968, KB4480970, KB4480973, KB4480975, KB4480978 (applies to 40 product versions)
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://www.exploit-db.com/exploits/46536/

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 CatalogKB2553332

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB2553332 — https://support.microsoft.com/help/2553332
    1
    KB2596760 — https://support.microsoft.com/help/2596760
    1
    KB3172522 — https://support.microsoft.com/help/3172522
    1
    KB4022162 — https://support.microsoft.com/help/4022162
    1
    KB4462112 — https://support.microsoft.com/help/4462112
    1
    KB4480116 — https://support.microsoft.com/help/4480116
    1
    KB4480961 — https://support.microsoft.com/help/4480961
    1
    KB4480962 — https://support.microsoft.com/help/4480962
    1
    KB4480963 — https://support.microsoft.com/help/4480963
    1
    KB4480965 — https://support.microsoft.com/help/4480965
    1
    KB4480966 — https://support.microsoft.com/help/4480966
    1
    KB4480968 — https://support.microsoft.com/help/4480968
    1
    KB4480970 — https://support.microsoft.com/help/4480970
    1
    KB4480973 — https://support.microsoft.com/help/4480973
    1
    KB4480975 — https://support.microsoft.com/help/4480975
    1
    KB4480978 — https://support.microsoft.com/help/4480978

Supersedes: KB4092433, KB4471318, KB4471320, KB4471321, KB4471325, KB4471330, KB4483187, KB4483228, KB4483229, KB4483232, KB4483234, KB4483235

Affected Products

    1
    Internet Explorer 10 on Windows Server 2012
    1
    Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1703 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 Version 1703 for x64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1709 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 Version 1709 for ARM64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1709 for x64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1803 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 Version 1803 for ARM64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1803 for x64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1809 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 Version 1809 for ARM64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1809 for x64-based Systems
    1
    Internet Explorer 11 on Windows 10 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 for x64-based Systems
    1
    Internet Explorer 11 on Windows 7 for 32-bit Systems Service Pack 1
    1
    Internet Explorer 11 on Windows 7 for x64-based Systems Service Pack 1
    1
    Internet Explorer 11 on Windows 8.1 for 32-bit systems
    1
    Internet Explorer 11 on Windows 8.1 for x64-based systems
    1
    (…20 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 (may or may not be required for this update)

Microsoft Update Catalog (manual download)

1
Open https://catalog.update.microsoft.com
2
Search for KB2553332
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 KB2553332 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4480116
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4480961
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4480962
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4480963
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4480965
    1
    (…14 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB2553332','KB2596760','KB3172522','KB4022162','KB4462112','KB4480116','KB4480961','KB4480962','KB4480963','KB4480965','KB4480966','KB4480968','KB4480970','KB4480973','KB4480975','KB4480978') }

References

    1
    Microsoft Security Response Center: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0541
    1
    KB article: https://support.microsoft.com/help/4480116
    1
    KB article: https://support.microsoft.com/help/4480961
    1
    KB article: https://support.microsoft.com/help/4480962
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2019-0541
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-0541

Discovery Credit

Eduardo Braun Prado working with iDefense Labs

PowerShell automationComing soon

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

References

↗ CVE-2019-0541↗ MSRC Advisory↗ NVD↗ KBKB2553332