IRONSMITHINTEL
HIGHCVSS7.5
|
Actively Exploited
|CISA KEV|CVE-2019-1367|Auth: none — unauthenticated|Reboot: required|Manual only

KB4517389: Windows Server Security Update (September 2019)

Microsoft Internet Explorer contains a memory corruption vulnerability in how the scripting engine handles objects in memory. Successful exploitation allows for remote code execution in the context of the current user.

Published Sep 23, 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. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2022-05-03 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Out-of-bounds Write (CWE-787) vulnerability in Microsoft Internet Explorer. A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka 'Scripting Engine Memory Corruption Vulnerability'. This CVE ID is unique from CVE-2019-1221. Exploitation requires remote network access, higher 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: 10, 11, 9
Fixed inKB4517389, KB4519338, KB4519974, KB4519976, KB4519998, KB4520002, KB4520004, KB4520005, KB4520007, KB4520008, KB4520010, KB4520011 (applies to 31 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 2021-11-03; federal agencies required to remediate by 2022-05-03.

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 CatalogKB4517389

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB4517389 — https://support.microsoft.com/help/4517389
    1
    KB4519338 — https://support.microsoft.com/help/4519338
    1
    KB4519974 — https://support.microsoft.com/help/4519974
    1
    KB4519976 — https://support.microsoft.com/help/4519976
    1
    KB4519998 — https://support.microsoft.com/help/4519998
    1
    KB4520002 — https://support.microsoft.com/help/4520002
    1
    KB4520004 — https://support.microsoft.com/help/4520004
    1
    KB4520005 — https://support.microsoft.com/help/4520005
    1
    KB4520007 — https://support.microsoft.com/help/4520007
    1
    KB4520008 — https://support.microsoft.com/help/4520008
    1
    KB4520010 — https://support.microsoft.com/help/4520010
    1
    KB4520011 — https://support.microsoft.com/help/4520011

Supersedes: KB4516026, KB4524135, KB4524147, KB4524148, KB4524149, KB4524150, KB4524151, KB4524152, KB4524153, KB4524154, KB4524156, KB4524157

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 Version 1903 for 32-bit Systems
    1
    Internet Explorer 11 on Windows 10 Version 1903 for ARM64-based Systems
    1
    Internet Explorer 11 on Windows 10 Version 1903 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
    (…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 KB4517389
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 KB4517389 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4517389
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4519338
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4519974
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4519976
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4519998
    1
    (…7 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB4517389','KB4519338','KB4519974','KB4519976','KB4519998','KB4520002','KB4520004','KB4520005','KB4520007','KB4520008','KB4520010','KB4520011') }

References

    1
    Microsoft Security Response Center: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1367
    1
    KB article: https://support.microsoft.com/help/4517389
    1
    KB article: https://support.microsoft.com/help/4519338
    1
    KB article: https://support.microsoft.com/help/4519974
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2019-1367
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-1367

Discovery Credit

Clément Lecigne of Google’s Threat Analysis Group

PowerShell automationComing soon

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

References

↗ CVE-2019-1367↗ MSRC Advisory↗ NVD↗ KBKB4517389