CASCACascade Atlas

Evidence dossier

CVE-2021-33739

Microsoft DWM Core Library Elevation of Privilege Vulnerability

Exploited in the wild (CISA KEV since Nov 3, 2021). microsoft reports CVSS 3.1 8.4. EPSS estimates 6.6% exploit likelihood as of Aug 27, 2026.

70.0–75.1Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

Microsoft DWM Core Library Elevation of Privilege Vulnerability

State
PUBLISHED
Published
Jun 8, 2021
Updated
Oct 21, 2025
Evidence coverage
92%

Evidence chronology

What was known when

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  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    microsoft

    Record text: Microsoft DWM Core Library Elevation of Privilege Vulnerability

    Inspect raw assertion
    Field
    container
    Value
    Microsoft DWM Core Library Elevation of Privilege Vulnerability
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 6.56% probability · 93.3th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.065550000000; percentile 0.933040000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Nov 3, 2021 · first observed Jul 19, 2026

Exploit likelihood6.55%

FIRST EPSS · score date Aug 27, 2026 · 93.3th percentile · first observed Aug 27, 2026

SeverityCVSS 8.4

microsoft · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
microsoftOriginal assertion
Record text

Microsoft DWM Core Library Elevation of Privilege Vulnerability

Inspect raw assertion
Field
container
Value
Microsoft DWM Core Library Elevation of Privilege Vulnerability
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

6.56% probability · 93.3th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.065550000000; percentile 0.933040000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
6Underlying assertions
6Canonical products
6Target assertions
0Constraint assertions

Grouped from 1 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

12 scope groups

microsoft · source assertedMicrosoftWindows 10 Version 1909Direct source scope
Affected: 10.0.0 to before 10.0.18363.1621 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.18363.1621", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 10 Version 2004Direct source scope
Affected: 10.0.0 to before 10.0.19041.1052 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19041.1052", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 10 Version 20H2Direct source scope
Affected: 10.0.0 to before 10.0.19042.1052 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19042.1052", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 10 Version 21H1Direct source scope
Affected: 10.0.0 to before 10.0.19043.1052 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19043.1052", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows Server version 2004Direct source scope
Affected: 10.0.0 to before 10.0.19041.1052 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19041.1052", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows Server version 20H2Direct source scope
Affected: 10.0.0 to before 10.0.19042.1052 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19042.1052", "versionType": "custom"}]
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_1909Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.18363.1621)Canonical identity product-ef5324dcc791e4e872d6c2be0aefa1d7687ca82c3b4ac5d1f72c76cce8395218Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 10.0.18363.1621
    Match ID
    25bdc753-1696-4a75-ac79-e482662bd743
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_2004Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19041.1052)Canonical identity product-9b245936275be71b526838fc72ea633d195b35bdd9dfc31bb6df51e7700edeccLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    through excluding 10.0.19041.1052
    Match ID
    4110ddef-afeb-469c-8ff1-9208d5ad254a
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_20h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19042.1052)Canonical identity product-55e90faed8848f3d316cf702d119e83086b6dc5a963d9947a7df1c589f50346dLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    through excluding 10.0.19042.1052
    Match ID
    a81d1961-6d36-4bbb-96c2-15d5480637ce
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_21h1Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19043.1052)Canonical identity product-e0c6c3f5c5e95b5b83fbbf719a7de2471749e1ca250bebf19bc7898a937a00edLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    through excluding 10.0.19043.1052
    Match ID
    579557c6-7d3c-4d9d-b8df-e3193c01715c
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2004Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19041.1052)Canonical identity product-571f6df0fa50d71be9551414060ed8bfcdb500437871cf9595b7fa6b034cecbdLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    through excluding 10.0.19041.1052
    Match ID
    854be587-9888-4365-abba-ac951dc7bcb4
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_20h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19042.1052)Canonical identity product-457c0c3b89fb1cf896e8491223eac8b0cb1ea61ce3174f915e4fe1032759d5a2Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    through excluding 10.0.19042.1052
    Match ID
    b963e9ab-d1f7-45d1-8b7e-675732475401

Affected-product evidence

Accepted scope and product mapping

6 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-457c0c3b89fb1cf896e8491223eac8b0cb1ea61ce3174f915e4fe1032759d5a2

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
987506c0-a187-4e05-a87b-985346b934e4
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-55e90faed8848f3d316cf702d119e83086b6dc5a963d9947a7df1c589f50346d

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
0372d7ac-49f1-457a-bd33-b8d6b8437177
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-571f6df0fa50d71be9551414060ed8bfcdb500437871cf9595b7fa6b034cecbd

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
9eb1d17b-8edf-44ba-87ea-73728cee10ac
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-9b245936275be71b526838fc72ea633d195b35bdd9dfc31bb6df51e7700edecc

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
73e4d0e0-82f5-4149-9ae6-ee220b5dbf79
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-e0c6c3f5c5e95b5b83fbbf719a7de2471749e1ca250bebf19bc7898a937a00ed

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
d6dec74f-9d41-47cd-a0ac-3e3141c83e0f
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-ef5324dcc791e4e872d6c2be0aefa1d7687ca82c3b4ac5d1f72c76cce8395218

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
dc0271e7-3371-4498-9011-3b1490fd8cb8
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
6
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
046614c2-704a-4763-b51c-c769f43b701a1d5bf6b8-fdf0-4b5f-8492-d1834f10923468ab30f8-ec1f-4134-af24-b89f764111b1a5f9f408-1bb2-4d81-85d3-f96a139c02c3eeb247b7-fd42-41e8-b826-a3403f1a170cf4dcb6e7-a36d-4eee-88d1-b6bac584bceb

Assessments

CVSS by origin

4.6
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8
NVDCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.4
secure@microsoft.comCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.4
microsoftCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

Direct CVE/CNA normalized decisions

8.4Priority eligible

microsoft

CVSS 3.1 · Primary · Original assertion · rank 1

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
Validation
Valid match
Recomputed
8.4
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.