OnlyFm252
Windows AppContainer

CVE-2021-40476 — Windows AppContainer Elevation Of Privilege Vulnerability

Important CVSS 7.5 EPSS 0.02274 2021-10 archive

Executive Summary

None

Overview

7.5
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Elevation of Privilege
Released Oct 12 2021
Last Updated Oct 12 2021
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.02274 — 0.80806 percentile
NVD CVSS 7.5 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
High
PRIVILEGES REQUIRED
Low
USER INTERACTION
Required
SCOPE
Changed
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.7

EPSS Score

0.02274
probability of exploitation in the next 30 days
0.80806 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

29 affected products
Product KB Article Severity Impact Restart Required
Windows 10 for 32-bit Systems 5006675 (Security Update) Important Elevation of Privilege Yes
Windows 10 for x64-based Systems 5006675 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1607 for 32-bit Systems 5006669 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1607 for x64-based Systems 5006669 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for 32-bit Systems 5006672 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for ARM64-based Systems 5006672 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1809 for x64-based Systems 5006672 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1909 for 32-bit Systems 5006667 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1909 for ARM64-based Systems 5006667 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 1909 for x64-based Systems 5006667 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 2004 for 32-bit Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 2004 for ARM64-based Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 2004 for x64-based Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 20H2 for 32-bit Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 20H2 for ARM64-based Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H1 for 32-bit Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H1 for ARM64-based Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 10 Version 21H1 for x64-based Systems 5006670 (Security Update) Important Elevation of Privilege Yes
Windows 11 version 21H2 for ARM64-based Systems 5006674 (Security Update) Important Elevation of Privilege Yes
Windows 11 version 21H2 for x64-based Systems 5006674 (Security Update) Important Elevation of Privilege Yes
Windows 8.1 for 32-bit systems 5006714 (Monthly Rollup) 5006729 (Security Only) Important Elevation of Privilege 5005613 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C 6.3.9600.20144 Yes 5006714 5006729 Windows 8.1 for x64-based systems 5006714 (Monthly Rollup) 5006729 (Security Only) Important Elevation of Privilege 5005613 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C 6.3.9600.20144 Yes 5006714 5006729 Windows RT 8.1 5006714 (Monthly Rollup) Important Elevation of Privilege Yes
Windows Server 2012 5006739 (Monthly Rollup) 5006732 (Security Only) Important Elevation of Privilege 5005623 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C 6.2.9200.23490 Yes 5006739 5006732 Windows Server 2012 (Server Core installation) 5006739 (Monthly Rollup) 5006732 (Security Only) Important Elevation of Privilege 5005623 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C 6.2.9200.23490 Yes 5006739 5006732 Windows Server 2012 R2 5006714 (Monthly Rollup) 5006729 (Security Only) Important Elevation of Privilege 5005613 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C 6.3.9600.20144 Yes 5006714 5006729 Windows Server 2012 R2 (Server Core installation) 5006714 (Monthly Rollup) 5006729 (Security Only) Important Elevation of Privilege 5005613 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C 6.3.9600.20144 Yes 5006714 5006729 Windows Server 2016 5006669 (Security Update) Important Elevation of Privilege Yes
Windows Server 2016 (Server Core installation) 5006669 (Security Update) Important Elevation of Privilege Yes
Windows Server 2019 5006672 (Security Update) Important Elevation of Privilege Yes
Windows Server 2019 (Server Core installation) 5006672 (Security Update) Important Elevation of Privilege Yes
Windows Server 2022 5006699 (Security Update) Important Elevation of Privilege Yes
Windows Server 2022 (Server Core installation) 5006699 (Security Update) Important Elevation of Privilege Yes
Windows Server, version 2004 (Server Core installation) 5006670 (Security Update) Important Elevation of Privilege Yes
Windows Server, version 20H2 (Server Core Installation) 5006670 (Security Update) Important Elevation of Privilege Yes

Patches

8 patches
Article Type Restart
5006675 Security Update Yes
5006669 Security Update Yes
5006672 Security Update Yes
5006667 Security Update Yes
5006670 Security Update Yes
5006674 Security Update Yes
5006714 Monthly Rollup Yes
5006699 Security Update Yes

Known Exploits

Acknowledgments

Google Project Zero

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