CVE-2021-40444

Microsoft MSHTML Remote Code Execution Vulnerability

CVE-2021-40444 is fixed in 42 products on 1 platform, first by KB5005563, released July 13, 2021. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, with known ransomware use. Patch Radar priority: Patch now.

Patch nowCISA KEVKnown ransomware usePublicly disclosed
CVSS
8.8
Important
Exploitation
Exploited
Reported by the vendor
CISA KEV
Nov 3, 2021
Federal due date Nov 17, 2021. Known ransomware use
EPSS
0.9784
99th percentile

<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. The attacker would then have to convince the user to open the malicious document. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.</p> <p>Microsoft Defender Antivirus and Microsoft Defender for Endpoint both provide detection and protections for the known vulnerability. Customers should keep antimalware products up to date. Customers who utilize automatic updates do not need to take additional action. Enterprise customers who manage updates should select the detection build 1.349.22.0 or newer and deploy it across their environments. Microsoft Defender for Endpoint alerts will be displayed as: “Suspicious Cpl File Execution”.</p> <p>Upon completion of this investigation, Microsoft will take the appropriate action to help protect our customers. This may include providing a security update through our monthly release process or providing an out-of-cycle security update, depending on customer needs.</p> <p>Please see the <strong>Mitigations</strong> and <strong>Workaround</strong> sections for important information about steps you can take to protect your system from this vulnerability.</p> <p><strong>UPDATE</strong> September 14, 2021: Microsoft has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. Please see the FAQ for important information about which updates are applicable to your system.</p>

Where it's fixed

ProductFixed inFixReleased
Microsoft
Windows 10 Version 1607 for 32-bit Systems 14393.4651 KB5005573 Sep 14, 2021
Windows 10 Version 1607 for x64-based Systems 14393.4651 KB5005573 Sep 14, 2021
Windows 10 Version 1809 for 32-bit Systems 17763.2183 KB5005568 Sep 14, 2021
Windows 10 Version 1809 for ARM64-based Systems 17763.2183 KB5005568 Sep 14, 2021
Windows 10 Version 1809 for x64-based Systems 17763.2183 KB5005568 Sep 14, 2021
Windows 10 Version 1909 for 32-bit Systems 18363.1801 KB5005566 Sep 14, 2021
Windows 10 Version 1909 for ARM64-based Systems 18363.1801 KB5005566 Sep 14, 2021
Windows 10 Version 1909 for x64-based Systems 18363.1801 KB5005566 Sep 14, 2021
Windows 10 Version 2004 for 32-bit Systems KB5005565 Sep 14, 2021
Windows 10 Version 2004 for ARM64-based Systems KB5005565 Sep 14, 2021
Windows 10 Version 2004 for x64-based Systems KB5005565 Sep 14, 2021
Windows 10 Version 20H2 for 32-bit Systems KB5005565 Sep 14, 2021
Windows 10 Version 20H2 for ARM64-based Systems KB5005565 Sep 14, 2021
Windows 10 Version 20H2 for x64-based Systems KB5005565 Sep 14, 2021
Windows 10 Version 21H1 for 32-bit Systems KB5005565 Sep 14, 2021
Windows 10 Version 21H1 for ARM64-based Systems KB5005565 Sep 14, 2021
Windows 10 Version 21H1 for x64-based Systems KB5005565 Sep 14, 2021
Windows 10 for 32-bit Systems 10240.19060 KB5005569 Sep 14, 2021
Windows 10 for x64-based Systems 10240.19060 KB5005569 Sep 14, 2021
Windows 7 for 32-bit Systems Service Pack 1 KB5019958 Nov 8, 2022
Windows 7 for 32-bit Systems Service Pack 1 KB5005633 Sep 14, 2021
Windows 7 for 32-bit Systems Service Pack 1 KB5005563 Jul 13, 2021
Windows 7 for x64-based Systems Service Pack 1 KB5019958 Nov 8, 2022
Windows 7 for x64-based Systems Service Pack 1 KB5005633 Sep 14, 2021
Windows 7 for x64-based Systems Service Pack 1 KB5005563 Jul 13, 2021
Windows 8.1 for 32-bit systems KB5005627 Sep 14, 2021
Windows 8.1 for 32-bit systems KB5005613 Sep 14, 2021
Windows 8.1 for 32-bit systems KB5005563 Jul 13, 2021
Windows 8.1 for x64-based systems KB5005627 Sep 14, 2021
Windows 8.1 for x64-based systems KB5005613 Sep 14, 2021
Windows 8.1 for x64-based systems KB5005563 Jul 13, 2021
Windows RT 8.1 KB5005613 Sep 14, 2021
Windows Server 2008 R2 for x64-based Systems Service Pack 1 KB5005633 Sep 14, 2021
Windows Server 2008 R2 for x64-based Systems Service Pack 1 KB5005563 Jul 13, 2021
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) KB5005633 Sep 14, 2021
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) KB5005563 Jul 13, 2021
Windows Server 2008 for 32-bit Systems Service Pack 2 KB5005606 Sep 14, 2021
Windows Server 2008 for 32-bit Systems Service Pack 2 KB5005563 Jul 13, 2021
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) KB5005606 Sep 14, 2021
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) KB5005563 Jul 13, 2021
Windows Server 2008 for x64-based Systems Service Pack 2 KB5005606 Sep 14, 2021
Windows Server 2008 for x64-based Systems Service Pack 2 KB5005563 Jul 13, 2021
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) KB5005606 Sep 14, 2021
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) KB5005563 Jul 13, 2021
Windows Server 2012 KB5005623 Sep 14, 2021
Windows Server 2012 KB5005563 Jul 13, 2021
Windows Server 2012 (Server Core installation) KB5005623 Sep 14, 2021
Windows Server 2012 (Server Core installation) KB5005563 Jul 13, 2021
Windows Server 2012 R2 KB5005613 Sep 14, 2021
Windows Server 2012 R2 KB5005563 Jul 13, 2021
Windows Server 2012 R2 (Server Core installation) KB5005613 Sep 14, 2021
Windows Server 2012 R2 (Server Core installation) KB5005563 Jul 13, 2021
Windows Server 2016 14393.4651 KB5005573 Sep 14, 2021
Windows Server 2016 (Server Core installation) 14393.4651 KB5005573 Sep 14, 2021
Windows Server 2019 17763.2183 KB5005568 Sep 14, 2021
Windows Server 2019 (Server Core installation) 17763.2183 KB5005568 Sep 14, 2021
Windows Server 2022 20348.230 KB5005575 Sep 14, 2021
Windows Server 2022 (Server Core installation) 20348.230 KB5005575 Sep 14, 2021
Windows Server, version 2004 (Server Core installation) KB5005565 Sep 14, 2021
Windows Server, version 20H2 (Server Core Installation) KB5005565 Sep 14, 2021

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