All vulnerabilities
CVE-2021-40444

Microsoft MSHTML Remote Code Execution Vulnerability

Microsoft MSHTML
Open in ThreatlineRecord JSON
CVSS
8.8High
ExploitationExploited in the wildAdded to KEV 3 Nov 2021. Known ransomware useCISA KEV
Exploit odds (EPSS)97.8%Chance of exploitation activity in the next 30 days, higher than 99.9% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in10.0.10240.19060Also 10.0.14393.4651, 10.0.17763.2183 and 9 moreCVE List
Federal deadline17 Nov 2021Remediation due date for US federal agenciesCISA KEV
CISA required actionApply updates per vendor instructions. CISA KEV

What fixes it

  • 10.0.10240.19060Windows 10 Version 1507CVE List
  • 10.0.14393.4651Windows 10 Version 1607CVE List
  • 10.0.17763.2183Windows 10 Version 1809CVE List
  • 10.0.18363.1801Windows 10 Version 1909CVE List
  • 10.0.19041.1237Windows 10 Version 2004CVE List
  • 10.0.19042.1237Windows 10 Version 20H2CVE List
Show all 25 fixed versions
  • 10.0.19043.1237Windows 10 Version 21H1CVE List
  • 6.1.7601.25712Windows 7CVE List
  • 6.1.7601.25712Windows 7 Service Pack 1CVE List
  • 6.3.9600.20120Windows 8.1CVE List
  • 6.1.7601.25712Windows Server 2008 R2 Service Pack 1CVE List
  • 6.1.7601.25712Windows Server 2008 R2 Service Pack 1 (Server Core installation)CVE List
  • 6.0.6003.21218Windows Server 2008 Service Pack 2CVE List
  • 6.0.6003.21218Windows Server 2008 Service Pack 2 (Server Core installation)CVE List
  • 6.2.9200.23462Windows Server 2012CVE List
  • 6.2.9200.23462Windows Server 2012 (Server Core installation)CVE List
  • 6.3.9600.20120Windows Server 2012 R2CVE List
  • 6.3.9600.20120Windows Server 2012 R2 (Server Core installation)CVE List
  • 10.0.14393.4651Windows Server 2016CVE List
  • 10.0.14393.4651Windows Server 2016 (Server Core installation)CVE List
  • 10.0.17763.2183Windows Server 2019CVE List
  • 10.0.17763.2183Windows Server 2019 (Server Core installation)CVE List
  • 10.0.20348.230Windows Server 2022CVE List
  • 10.0.19041.1237Windows Server version 2004CVE List
  • 10.0.19042.1237Windows Server version 20H2CVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 15 Sep 2021, 11:24 UTCPublishedCVE List
  2. 23 Sep 2021Exploit code publicMetasploit
  3. 3 Nov 2021Added to CISA KEVCISA KEV

Public exploit code and templates 1

  • Exploit moduleMicrosoft Office Word Malicious MSHTML RCE 23 Sep 2021Metasploit

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

Microsoft MSHTML contains a unspecified vulnerability that allows for remote code execution.

Text from CVE List

Affected versions 26

  • Windows 10 Version 1507affected: 10.0.10240.0 before 10.0.10240.19060CVE List
  • Windows 10 Version 1607affected: 10.0.14393.0 before 10.0.14393.4651CVE List
  • Windows 10 Version 1809affected: 10.0.17763.0 before 10.0.17763.2183CVE List
  • Windows 10 Version 1809affected: 10.0.0 before 10.0.17763.2183CVE List
  • Windows 10 Version 1909affected: 10.0.0 before 10.0.18363.1801CVE List
  • Windows 10 Version 2004affected: 10.0.0 before 10.0.19041.1237CVE List
  • Windows 10 Version 20H2affected: 10.0.0 before 10.0.19042.1237CVE List
  • Windows 10 Version 21H1affected: 10.0.0 before 10.0.19043.1237CVE List
  • Windows 7affected: 6.1.0 before 6.1.7601.25712CVE List
  • Windows 7 Service Pack 1affected: 6.1.0 before 6.1.7601.25712CVE List
  • Windows 8.1affected: 6.3.0 before 6.3.9600.20120CVE List
  • Windows Server 2008 R2 Service Pack 1affected: 6.1.7601.0 before 6.1.7601.25712CVE List
  • Windows Server 2008 R2 Service Pack 1 (Server Core installation)affected: 6.1.7601.0 before 6.1.7601.25712CVE List
  • Windows Server 2008 Service Pack 2affected: 6.0.6003.0 before 6.0.6003.21218CVE List
  • Windows Server 2008 Service Pack 2 (Server Core installation)affected: 6.0.6003.0 before 6.0.6003.21218CVE List
  • Windows Server 2012affected: 6.2.9200.0 before 6.2.9200.23462CVE List
  • Windows Server 2012 (Server Core installation)affected: 6.2.9200.0 before 6.2.9200.23462CVE List
  • Windows Server 2012 R2affected: 6.3.9600.0 before 6.3.9600.20120CVE List
  • Windows Server 2012 R2 (Server Core installation)affected: 6.3.9600.0 before 6.3.9600.20120CVE List
  • Windows Server 2016affected: 10.0.14393.0 before 10.0.14393.4651CVE List
  • Windows Server 2016 (Server Core installation)affected: 10.0.14393.0 before 10.0.14393.4651CVE List
  • Windows Server 2019affected: 10.0.17763.0 before 10.0.17763.2183CVE List
  • Windows Server 2019 (Server Core installation)affected: 10.0.17763.0 before 10.0.17763.2183CVE List
  • Windows Server 2022affected: 10.0.20348.0 before 10.0.20348.230CVE List
  • Windows Server version 2004affected: 10.0.0 before 10.0.19041.1237CVE List
  • Windows Server version 20H2affected: 10.0.0 before 10.0.19042.1237CVE List

References 4