SARA / Free Tools / CVE / CVE-2021-40444

CVE-2021-40444 — Microsoft MSHTML Remote Code Execution Vulnerability

<p>Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. Microsoft is aware of targeted attacks that attempt to exploit this vulnerability by using specially-crafted Microsoft Office documents.</p> <p&

CVSS
8.8 HIGH
EPSS
94.33% (top 0.00%)
CWE
—
Published
2021-09-15T11:24:26.000Z
Last modified
2026-03-11T03:55:26.291Z
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:C
CISA KEV — Actively Exploited
Added to KEV
2021-11-03
BOD 22-01 due
2021-11-17
Ransomware use
Known
View KEV detail
CVE-2021-40444 on CISA KEV →

01What is this vulnerability?

<p>Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. Microsoft is aware of targeted attacks that attempt to exploit this vulnerability by using specially-crafted Microsoft Office documents.</p> <p>An attacker could craft a malicious ActiveX control to be used by a Microsoft Office document that hosts the browser rendering engine…

02Affected products

VendorProductVersions
MicrosoftWindows 10 Version 180910.0.0
MicrosoftWindows Server 201910.0.0
MicrosoftWindows Server 2019 (Server Core installation)10.0.0
MicrosoftWindows 10 Version 190910.0.0
MicrosoftWindows 10 Version 21H110.0.0
MicrosoftWindows Server 202210.0.0
MicrosoftWindows 10 Version 200410.0.0
MicrosoftWindows Server version 200410.0.0
MicrosoftWindows 10 Version 20H210.0.0
MicrosoftWindows Server version 20H210.0.0
MicrosoftWindows 10 Version 150710.0.0
MicrosoftWindows 10 Version 160710.0.0
MicrosoftWindows Server 201610.0.0
MicrosoftWindows Server 2016 (Server Core installation)10.0.0
MicrosoftWindows 76.1.0, 6.1.0, 6.1.0
MicrosoftWindows 7 Service Pack 16.1.0, 6.1.0, 6.1.0
MicrosoftWindows 8.16.3.0, 6.3.0
MicrosoftWindows Server 2008 Service Pack 26.0.0, 6.0.0
MicrosoftWindows Server 2008 Service Pack 2 (Server Core installation)6.0.0, 6.0.0
MicrosoftWindows Server 2008 Service Pack 26.0.0, 6.0.0
MicrosoftWindows Server 2008 R2 Service Pack 16.1.0, 6.1.0
MicrosoftWindows Server 2008 R2 Service Pack 1 (Server Core installation)6.0.0, 6.0.0
MicrosoftWindows Server 20126.2.0, 6.2.0
MicrosoftWindows Server 2012 (Server Core installation)6.2.0, 6.2.0
MicrosoftWindows Server 2012 R26.3.0, 6.3.0
MicrosoftWindows Server 2012 R2 (Server Core installation)6.3.0, 6.3.0

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2021-11-03. Ransomware use: Known.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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