CVE-2020-16910 — Windows Security Feature Bypass Vulnerability

Executive Summary

A security feature bypass vulnerability exists when Microsoft Windows fails to handle file creation permissions, which could allow an attacker to create files in a protected Unified Extensible Firmware Interface (UEFI) location. To exploit this vulnerability, an attacker could run a specially crafted application to bypass Unified Extensible Firmware Interface (UEFI) variable security in Windows. The security update addresses the vulnerability by correcting security feature behavior to enforce permissions.

Overview

6.2

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Security Feature Bypass

Released Oct 13 2020

Last Updated Oct 13 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.02581 — 0.83197 percentile

CVSS Vector

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

Temporal Score: 5.6

EPSS Score

0.02581

probability of exploitation in the next 30 days

0.83197 percentile - updated 2026-06-20

View on FIRST.org

Affected Products

29 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 for 32-bit Systems	`4580327 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 for x64-based Systems	`4580327 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1607 for 32-bit Systems	`4580346 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1607 for x64-based Systems	`4580346 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1709 for 32-bit Systems	`4580328 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1709 for ARM64-based Systems	`4580328 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1709 for x64-based Systems	`4580328 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for 32-bit Systems	`4580330 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for ARM64-based Systems	`4580330 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for x64-based Systems	`4580330 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for 32-bit Systems	`4577668 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for ARM64-based Systems	`4577668 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for x64-based Systems	`4577668 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for 32-bit Systems	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for ARM64-based Systems	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for x64-based Systems	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1909 for 32-bit Systems	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1909 for ARM64-based Systems	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1909 for x64-based Systems	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 2004 for 32-bit Systems	`4579311 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 2004 for ARM64-based Systems	`4579311 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 2004 for x64-based Systems	`4579311 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2016	`4580346 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2016 (Server Core installation)	`4580346 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019	`4577668 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019 (Server Core installation)	`4577668 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1903 (Server Core installation)	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1909 (Server Core installation)	`4577671 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 2004 (Server Core installation)	`4579311 (Security Update)`	Important	Security Feature Bypass	Yes

Patches

7 patches

Article	Type	Restart
`4580327`	Security Update	Yes
`4580346`	Security Update	Yes
`4580328`	Security Update	Yes
`4580330`	Security Update	Yes
`4577668`	Security Update	Yes
`4577671`	Security Update	Yes
`4579311`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Jonas Lykkegård

References

MSRC Advisory MITRE NVD