Vulnerability CVE-2021-34484: Complete Guide

This guide provides a clear overview of vulnerability cve-2021-34484, including the main concepts, practical steps, and common questions. Use it to understand the topic, compare the available options, and make a more informed decision.

This vulnerability scores 7.8 in the CVSS v3. So far, there is no sign of this vulnerability being exploited by attackers, but there are still many potential risks.

In August 2021, Microsoft released an official patch for this vulnerability shortly after it was discovered. After that, this bug was marked as fixed, but in fact, Microsoft's patch only fixed part of the problem, the vulnerability still existed.

A few months ago, 0patch discovered this vulnerability in the Windows User Profile Service. So 0patch took action and self-released the patch profext.dll.

By January 2022, Microsoft fixed this bug and replaced the "profext.dll" file, which caused the unofficial fix to be removed from everyone who applied the January Windows updates. 2022. In fact, Microsoft's patches did not fix the error, even breaking the previous unofficial patch of 0patch.

0patch continues to have to update its patch to be compatible with the latest Microsoft Tuesday Update and provide it for free to all registered users.

Affected and updated versions of Windows include:

• Windows 10 v21H1 (32 & 64 bit) updated with the March 2022 Update
• Windows 10 v20H2 (32 & 64 bit) updated with March 2022 Update
• Windows 10 v1909 (32 & 64 bit) updated with the March 2022 Update
• Windows Server 2019 64 bit updated with March 2022 Update

Microsoft said that it is aware of this case and will take appropriate steps to protect the safety of users.

Conclusion

Understanding Vulnerability CVE-2021-34484 makes it easier to compare options, avoid common mistakes, and apply the information in this guide more effectively. Review the relevant requirements before making changes or choosing a solution.