CVE-2021-40456 Explained : Impact and Mitigation

Windows AD FS Security Feature Bypass Vulnerability was published on October 12, 2021, by Microsoft.

Understanding CVE-2021-40456

This section provides an in-depth look at the Windows AD FS Security Feature Bypass Vulnerability.

What is CVE-2021-40456?

CVE-2021-40456 is a security feature bypass vulnerability affecting various versions of Windows Server.

The Impact of CVE-2021-40456

The impact of this vulnerability is classified as 'Security Feature Bypass' with a CVSS base severity of MEDIUM and a base score of 5.3.

Technical Details of CVE-2021-40456

This section delves into the technical aspects of the CVE-2021-40456 vulnerability.

Vulnerability Description

The vulnerability allows attackers to bypass security features in Windows AD FS.

Affected Systems and Versions

The following systems and versions are affected:

Windows Server 2019
Version: 10.0.17763.2237
Windows Server 2019 (Server Core installation)
Version: 10.0.17763.2237
Windows Server 2022
Version: 10.0.20348.288
Windows Server version 2004
Version: 10.0.19041.1288
Windows Server version 20H2
Version: 10.0.19042.1288

Exploitation Mechanism

Attackers can exploit this vulnerability to bypass security features in the affected Windows Server versions.

Mitigation and Prevention

This section outlines the steps to mitigate and prevent the CVE-2021-40456 vulnerability.

Immediate Steps to Take

Apply the necessary security updates provided by Microsoft.
Monitor system logs for any suspicious activities.
Implement strong access controls.

Long-Term Security Practices

Regularly update and patch systems to ensure security.
Conduct security assessments and penetration testing.
Educate users and administrators about security best practices.

Patching and Updates

Ensure that affected systems are updated with the latest security patches from Microsoft.