How severe is CVE-2021-33739?

CVE-2021-33739 has a CVSS 3.1 base score of 8.4 (HIGH). EPSS estimates a 6.6% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-33739: Microsoft DWM Core Library Elevation of Privilege

CISA Known Exploited Vulnerabilities

Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2021-11-17

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-33739

Description

Microsoft DWM Core Library Elevation of Privilege Vulnerability

Severity

CVSS 3.1 · CNA8.4 HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
Microsoft	Windows 10 Version 1909	10.0.0 to <10.0.18363.1621
Microsoft	Windows 10 Version 21H1	10.0.0 to <10.0.19043.1052
Microsoft	Windows 10 Version 2004	10.0.0 to <10.0.19041.1052
Microsoft	Windows Server version 2004	10.0.0 to <10.0.19041.1052
Microsoft	Windows 10 Version 20H2	10.0.0 to <10.0.19042.1052
Microsoft	Windows Server version 20H2	10.0.0 to <10.0.19042.1052

References

1 Links

Other references

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33739

Record Details

Published

2021-06-08

Last updated

2025-10-21

Assigner (CNA)

microsoft

Credited to

More from Microsoft

CVE-2019-07089.8

Microsoft Remote Desktop Services Remote Code Execution Vulnerability

CVE-2021-344739.1

Microsoft Exchange Server Remote Code Execution Vulnerability

CVE-2025-537709.8

Microsoft SharePoint Server Remote Code Execution Vulnerability

CVE-2021-268559.1

Microsoft Exchange Server Remote Code Execution Vulnerability

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.