CVE-2021-40444 : Exploit Details and Defense Strategies

A remote code execution vulnerability in MSHTML affecting Microsoft Windows has been identified. This CVE record provides details on the affected products, the exploitation mechanism, impact, and mitigation steps.

Understanding CVE-2021-40444

Microsoft is investigating reports of a remote code execution vulnerability in MSHTML that affects Microsoft Windows. This CVE record sheds light on the intricacies of the vulnerability.

What is CVE-2021-40444?

Microsoft is aware of targeted attacks using specially-crafted Microsoft Office documents to exploit this vulnerability. The attacker could use a malicious ActiveX control in a Microsoft Office document to host the browser rendering engine.

The Impact of CVE-2021-40444

Users with fewer system rights are less impacted than those with administrative rights.
Microsoft Defender Antivirus and Microsoft Defender for Endpoint offer protection.
Security updates have been released by Microsoft.

Technical Details of CVE-2021-40444

This section delves into the specifics of the vulnerability, including the description, affected systems, versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability allows remote code execution in MSHTML on Windows systems.

Affected Systems and Versions

Windows 10, Versions 1809, 1909, 21H1, 2004, 20H2, 1507, and 1607
Windows Server 2019, 2019 Server Core, 2022
Windows 7, 7 Service Pack 1, 8.1, Server 2008, 2008 Service Pack 2, 2012, 2012 R2

Exploitation Mechanism

Attacker must convince user to open malicious Microsoft Office document with crafted ActiveX control.

Mitigation and Prevention

Learn about the steps to mitigate the vulnerability and prevent exploitation.

Immediate Steps to Take

Keep antimalware products up to date.
Utilize automatic updates or deploy detection build 1.349.22.0 or higher for enterprise customers.

Long-Term Security Practices

Regularly update systems with the latest security patches.
Educate users on safe browsing habits and avoiding suspicious documents.
Implement security best practices.

Patching and Updates

Microsoft has released security updates for CVE-2021-40444.