All vulnerabilities
CVE-2021-40449

Microsoft Windows Win32k Privilege Escalation Vulnerability

Microsoft WindowsOperating systems
Open in ThreatlineRecord JSON
CVSS
7.8High
ExploitationExploited in the wildAdded to KEV 17 Nov 2021. Known ransomware useCISA KEV
Exploit odds (EPSS)81.9%Chance of exploitation activity in the next 30 days, higher than 99% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in10.0.17763.2237Also 10.0.18363.1854, 10.0.19041.1288 and 9 moreCVE List
Federal deadline1 Dec 2021Remediation due date for US federal agenciesCISA KEV
CISA required actionApply updates per vendor instructions. CISA KEV

What fixes it

  • 10.0.17763.2237Windows 10 Version 1809CVE List
  • 10.0.17763.2237Windows Server 2019CVE List
  • 10.0.17763.2237Windows Server 2019 (Server Core installation)CVE List
  • 10.0.18363.1854Windows 10 Version 1909CVE List
  • 10.0.19041.1288Windows 10 Version 21H1CVE List
  • 10.0.20348.288Windows Server 2022CVE List
Show all 27 fixed versions
  • 10.0.19041.1288Windows 10 Version 2004CVE List
  • 10.0.19041.1288Windows Server version 2004CVE List
  • 10.0.19041.1288Windows 10 Version 20H2CVE List
  • 10.0.19042.1288Windows Server version 20H2CVE List
  • 10.0.22000.258Windows 11 version 21H2CVE List
  • 10.0.10240.19086Windows 10 Version 1507CVE List
  • 10.0.14393.4704Windows 10 Version 1607CVE List
  • 10.0.14393.4704Windows Server 2016CVE List
  • 10.0.14393.4704Windows Server 2016 (Server Core installation)CVE List
  • 6.1.7601.25740Windows 7CVE List
  • 6.1.7601.25740Windows 7 Service Pack 1CVE List
  • 6.3.9600.20144Windows 8.1CVE List
  • 6.0.6003.21251Windows Server 2008 Service Pack 2CVE List
  • 6.0.6003.21251Windows Server 2008 Service Pack 2 (Server Core installation)CVE List
  • 6.0.6003.21251Windows Server 2008 Service Pack 2CVE List
  • 6.1.7601.25740Windows Server 2008 R2 Service Pack 1CVE List
  • 6.1.7601.25740Windows Server 2008 R2 Service Pack 1 (Server Core installation)CVE List
  • 6.2.9200.23490Windows Server 2012CVE List
  • 6.2.9200.23490Windows Server 2012 (Server Core installation)CVE List
  • 6.3.9600.20144Windows Server 2012 R2CVE List
  • 6.3.9600.20144Windows Server 2012 R2 (Server Core installation)CVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 12 Oct 2021Exploit code publicMetasploit
  2. 13 Oct 2021, 00:26 UTCPublishedCVE List
  3. 17 Nov 2021Added to CISA KEVCISA KEV

Public exploit code and templates 1

  • Exploit moduleWin32k NtGdiResetDC Use After Free Local Privilege Elevation 12 Oct 2021Metasploit

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

Unspecified vulnerability allows for an authenticated user to escalate privileges.

Text from CVE List

Affected versions 27

  • Windows 10 Version 1809affected: 10.0.0 before 10.0.17763.2237CVE List
  • Windows Server 2019affected: 10.0.0 before 10.0.17763.2237CVE List
  • Windows Server 2019 (Server Core installation)affected: 10.0.0 before 10.0.17763.2237CVE List
  • Windows 10 Version 1909affected: 10.0.0 before 10.0.18363.1854CVE List
  • Windows 10 Version 21H1affected: 10.0.0 before 10.0.19041.1288CVE List
  • Windows Server 2022affected: 10.0.0 before 10.0.20348.288CVE List
  • Windows 10 Version 2004affected: 10.0.0 before 10.0.19041.1288CVE List
  • Windows Server version 2004affected: 10.0.0 before 10.0.19041.1288CVE List
  • Windows 10 Version 20H2affected: 10.0.0 before 10.0.19041.1288CVE List
  • Windows Server version 20H2affected: 10.0.0 before 10.0.19042.1288CVE List
  • Windows 11 version 21H2affected: 10.0.0 before 10.0.22000.258CVE List
  • Windows 10 Version 1507affected: 10.0.0 before 10.0.10240.19086CVE List
  • Windows 10 Version 1607affected: 10.0.0 before 10.0.14393.4704CVE List
  • Windows Server 2016affected: 10.0.0 before 10.0.14393.4704CVE List
  • Windows Server 2016 (Server Core installation)affected: 10.0.0 before 10.0.14393.4704CVE List
  • Windows 7affected: 6.1.0 before 6.1.7601.25740CVE List
  • Windows 7 Service Pack 1affected: 6.1.0 before 6.1.7601.25740CVE List
  • Windows 8.1affected: 6.3.0 before 6.3.9600.20144CVE List
  • Windows Server 2008 Service Pack 2affected: 6.0.0 before 6.0.6003.21251CVE List
  • Windows Server 2008 Service Pack 2 (Server Core installation)affected: 6.0.0 before 6.0.6003.21251CVE List
  • Windows Server 2008 Service Pack 2affected: 6.0.0 before 6.0.6003.21251CVE List
  • Windows Server 2008 R2 Service Pack 1affected: 6.1.0 before 6.1.7601.25740CVE List
  • Windows Server 2008 R2 Service Pack 1 (Server Core installation)affected: 6.0.0 before 6.1.7601.25740CVE List
  • Windows Server 2012affected: 6.2.0 before 6.2.9200.23490CVE List
  • Windows Server 2012 (Server Core installation)affected: 6.2.0 before 6.2.9200.23490CVE List
  • Windows Server 2012 R2affected: 6.3.0 before 6.3.9600.20144CVE List
  • Windows Server 2012 R2 (Server Core installation)affected: 6.3.0 before 6.3.9600.20144CVE List

References 3