CVE-2021-33739: Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
CVSS: 8.4v3.1HighKEVAnalyzed
Published 08-06-2021Last modified 21-10-2025
Vulnerability summary
CVE-2021-33739 is a high (CVSS 8.4) vulnerability in Microsoft Windows. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 6.55% chance of exploitation in the next 30 days, higher than 93.7% of scored vulnerabilities.
CVSS score
8.4/10
010
High · v3.1 (CVE.org)EPSS score
6.55%
0%100%
Low · 0.00 pp in 30 daysKEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 08-06-2021PublishedVulnerability first disclosed.
- 03-11-2021Added to CISA KEVMicrosoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
- 17-11-2021CISA remediation dueApply updates per vendor instructions.
- 21-10-2025Last modifiedVulnerability information updated.
Description
Microsoft DWM Core Library Elevation of Privilege Vulnerability
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 8.4Preferred score · CVE.org (CNA)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:CSourcesAll 2 agree
- NVDNIST8.4HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Medium 4.6Preferred score · NVD (NIST)
AV:L/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
6.55%
Chance of exploitation in the next 30 days
Percentile
94%
Versus all other CVEs
30-day change
0.00 pp
From 6.55% on 20-09-2026
20-09-202620-10-2026
EPSS score6.55%
Known exploited
Compare KEV catalogs- Added
- 03-11-2021
- Federal due date
- 17-11-2021
CISA required action
Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2021-33739
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Microsoft12 products
- windows_10_1909< 10.0.18363.1621
- windows_10_2004< 10.0.19041.1052
- windows_10_20h2< 10.0.19042.1052
- windows_10_21h1< 10.0.19043.1052
- windows 10 version 1909≥ 10.0.0, < 10.0.18363.1621
1 vendor · 12 products
References
2 links- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33739X Refsource MISCPatchVendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33739Government ResourceUS Government Resource