CVE-2021-40449

Win32k Elevation of Privilege Vulnerability

Score

CVSS 3.1 7.8 High

Status

Analyzed - secure@microsoft.com

Published

2021-10-13

Last modified

2025-10-21

Known exploited (CISA KEV)

since 2021-11-17, action due 2021-12-01: Apply updates per vendor instructions.

Weaknesses

CWE-416

Affected products

• Windows 10 1507 (Microsoft)
• Windows 10 1607 (Microsoft)
• Windows 10 1809 (Microsoft)
• Windows 10 1909 (Microsoft)
• Windows 10 2004 (Microsoft)
• Windows 10 20H2 (Microsoft)
• Windows 10 20h2 (Microsoft)
• Windows 10 21H1 (Microsoft)
• Windows 10 21h1 (Microsoft)
• Windows 11 (Microsoft)
• Windows 11 21H2 (Microsoft)
• Windows 11 21h2 (Microsoft)
• Windows 7 (Microsoft)
• Windows 8.1 (Microsoft)
• Windows Rt 8.1 (Microsoft)
• Windows Server 2004 (Microsoft)
• Windows Server 2008 (Microsoft)
• Windows Server 2008 R2 (Microsoft)
• Windows Server 2008 Sp2 (Microsoft)
• Windows Server 2012 (Microsoft)
• Windows Server 2012 R2 (Microsoft)
• Windows Server 2016 (Microsoft)
• Windows Server 2019 (Microsoft)
• Windows Server 2022 (Microsoft)
• Windows Server 20H2 (Microsoft)
• Windows Server 20h2 (Microsoft)

References

• http://packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-After-Free-Local-Privilege-Escalation.html
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40449