Security News > 2022 > March > Windows zero-day flaw giving admin rights gets unofficial patch, again

A Windows local privilege escalation zero-day vulnerability that Microsoft has failed to fully address for several months now, allows users to gain administrative privileges in Windows 10, Windows 11, and Windows Server.
According to the 0patch team, which has been unofficially providing fixes for discontinued Windows versions and some vulnerabilities that Microsoft won't address, the flaw is still a zero-day.
The Windows User Profile Service Elevation of Privilege Vulnerability, tracked as CVE-2021-34484, was discovered by security researcher Abdelhamid Naceri and disclosed to Microsoft, who fixed it as part of the August 2021 Patch Tuesday.
Soon after the fix was released, Naceri noticed that Microsoft's patch was incomplete and presented a proof of concept that bypassed it on all Windows versions.
Microsoft's second fixing attempt replaced the "Profext.dll" file, leading to the removal of the unofficial fix from everyone who had applied the January 2022 Windows updates.
It should be noted that Windows 10 1803, Windows 10 1809, and Windows 10 2004 are still protected by 0patch's original patch, as those devices have reached the end of support and did not receive the Microsoft update that replaced the DLL. How to install the micro-patch.
News URL
Related news
- Week in review: Exploited Ivanti Connect Secure zero-day, Patch Tuesday forecast (source)
- Microsoft January 2025 Patch Tuesday fixes 8 zero-days, 159 flaws (source)
- Microsoft fixes actively exploited Windows Hyper-V zero-day flaws (source)
- Windows Patch Tuesday hits snag with Citrix software, workarounds published (source)
- 7-Zip fixes bug that bypasses Windows MoTW security warnings, patch now (source)
- Patch procrastination leaves 50,000 Fortinet firewalls vulnerable to zero-day (source)
- Don't want your Kubernetes Windows nodes hijacked? Patch this hole now (source)
- Microsoft February 2025 Patch Tuesday fixes 4 zero-days, 55 flaws (source)
- Patch Tuesday: Microsoft Patches Two Actively Exploited Zero-Day Flaws (source)
Related Vulnerability
DATE | CVE | VULNERABILITY TITLE | RISK |
---|---|---|---|
2021-08-12 | CVE-2021-34484 | Unspecified vulnerability in Microsoft products Windows User Profile Service Elevation of Privilege Vulnerability | 0.0 |