All vulnerabilities
CVE-2021-36955

Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability

Microsoft WindowsOperating systems
Open in ThreatlineRecord JSON
CVSS
7.8High
ExploitationExploited in the wildAdded to KEV 3 Nov 2021. Known ransomware useCISA KEV
Exploit odds (EPSS)4.07%Chance of exploitation activity in the next 30 days, higher than 90% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in10.0.10240.19060Also 10.0.14393.4651, 10.0.17763.2183 and 9 moreCVE List
Federal deadline17 Nov 2021Remediation due date for US federal agenciesCISA KEV
CISA required actionApply updates per vendor instructions. CISA KEV

What fixes it

  • 10.0.10240.19060Windows 10 Version 1507CVE List
  • 10.0.14393.4651Windows 10 Version 1607CVE List
  • 10.0.17763.2183Windows 10 Version 1809CVE List
  • 10.0.18363.1801Windows 10 Version 1909CVE List
  • 10.0.19041.1237Windows 10 Version 2004CVE List
  • 10.0.19042.1237Windows 10 Version 20H2CVE List
Show all 25 fixed versions
  • 10.0.19043.1237Windows 10 Version 21H1CVE List
  • 6.1.7601.25712Windows 7CVE List
  • 6.1.7601.25712Windows 7 Service Pack 1CVE List
  • 6.3.9600.20120Windows 8.1CVE List
  • 6.1.7601.25712Windows Server 2008 R2 Service Pack 1CVE List
  • 6.1.7601.25712Windows Server 2008 R2 Service Pack 1 (Server Core installation)CVE List
  • 6.0.6003.21218Windows Server 2008 Service Pack 2CVE List
  • 6.0.6003.21218Windows Server 2008 Service Pack 2 (Server Core installation)CVE List
  • 6.2.9200.23462Windows Server 2012CVE List
  • 6.2.9200.23462Windows Server 2012 (Server Core installation)CVE List
  • 6.3.9600.20120Windows Server 2012 R2CVE List
  • 6.3.9600.20120Windows Server 2012 R2 (Server Core installation)CVE List
  • 10.0.14393.4651Windows Server 2016CVE List
  • 10.0.14393.4651Windows Server 2016 (Server Core installation)CVE List
  • 10.0.17763.2183Windows Server 2019CVE List
  • 10.0.17763.2183Windows Server 2019 (Server Core installation)CVE List
  • 10.0.20348.230Windows Server 2022CVE List
  • 10.0.19041.1237Windows Server version 2004CVE List
  • 10.0.19042.1237Windows Server version 20H2CVE 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. 15 Sep 2021, 11:23 UTCPublishedCVE List
  2. 3 Nov 2021Added to CISA KEVCISA KEV

Description

Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.

Text from CVE List

Affected versions 26

  • Windows 10 Version 1507affected: 10.0.10240.0 before 10.0.10240.19060CVE List
  • Windows 10 Version 1607affected: 10.0.14393.0 before 10.0.14393.4651CVE List
  • Windows 10 Version 1809affected: 10.0.17763.0 before 10.0.17763.2183CVE List
  • Windows 10 Version 1809affected: 10.0.0 before 10.0.17763.2183CVE List
  • Windows 10 Version 1909affected: 10.0.0 before 10.0.18363.1801CVE List
  • Windows 10 Version 2004affected: 10.0.0 before 10.0.19041.1237CVE List
  • Windows 10 Version 20H2affected: 10.0.0 before 10.0.19042.1237CVE List
  • Windows 10 Version 21H1affected: 10.0.0 before 10.0.19043.1237CVE List
  • Windows 7affected: 6.1.0 before 6.1.7601.25712CVE List
  • Windows 7 Service Pack 1affected: 6.1.0 before 6.1.7601.25712CVE List
  • Windows 8.1affected: 6.3.0 before 6.3.9600.20120CVE List
  • Windows Server 2008 R2 Service Pack 1affected: 6.1.7601.0 before 6.1.7601.25712CVE List
  • Windows Server 2008 R2 Service Pack 1 (Server Core installation)affected: 6.1.7601.0 before 6.1.7601.25712CVE List
  • Windows Server 2008 Service Pack 2affected: 6.0.6003.0 before 6.0.6003.21218CVE List
  • Windows Server 2008 Service Pack 2 (Server Core installation)affected: 6.0.6003.0 before 6.0.6003.21218CVE List
  • Windows Server 2012affected: 6.2.9200.0 before 6.2.9200.23462CVE List
  • Windows Server 2012 (Server Core installation)affected: 6.2.9200.0 before 6.2.9200.23462CVE List
  • Windows Server 2012 R2affected: 6.3.9600.0 before 6.3.9600.20120CVE List
  • Windows Server 2012 R2 (Server Core installation)affected: 6.3.9600.0 before 6.3.9600.20120CVE List
  • Windows Server 2016affected: 10.0.14393.0 before 10.0.14393.4651CVE List
  • Windows Server 2016 (Server Core installation)affected: 10.0.14393.0 before 10.0.14393.4651CVE List
  • Windows Server 2019affected: 10.0.17763.0 before 10.0.17763.2183CVE List
  • Windows Server 2019 (Server Core installation)affected: 10.0.17763.0 before 10.0.17763.2183CVE List
  • Windows Server 2022affected: 10.0.20348.0 before 10.0.20348.230CVE List
  • Windows Server version 2004affected: 10.0.0 before 10.0.19041.1237CVE List
  • Windows Server version 20H2affected: 10.0.0 before 10.0.19042.1237CVE List

References 4