CVE-2020-1346 — Windows Modules Installer Elevation of Privilege Vulnerability

Executive Summary

An elevation of privilege vulnerability exists when the Windows Modules Installer improperly handles file operations. An attacker who successfully exploited this vulnerability could gain elevated privileges. To exploit the vulnerability, an attacker would first need code execution on a victim system. An attacker could then run a specially crafted application. The security update addresses the vulnerability by ensuring the Windows Modules Installer properly handles file operations.

Overview

7.8

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Released Jul 14 2020

Last Updated Jul 14 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.00738 — 0.49678 percentile

NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

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

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 7.0

EPSS Score

0.00738

probability of exploitation in the next 30 days

0.49678 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

44 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 for 32-bit Systems	`4565911 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 for x64-based Systems	`4565911 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1607 for 32-bit Systems	`4565912 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1607 for x64-based Systems	`4565912 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1709 for 32-bit Systems	`4565553 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1709 for ARM64-based Systems	`4565553 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1709 for x64-based Systems	`4565553 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1803 for 32-bit Systems	`4565552 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1803 for ARM64-based Systems	`4565552 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1803 for x64-based Systems	`4565552 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for 32-bit Systems	`4558997 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for ARM64-based Systems	`4558997 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for x64-based Systems	`4558997 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1903 for 32-bit Systems	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1903 for ARM64-based Systems	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1903 for x64-based Systems	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for 32-bit Systems	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for ARM64-based Systems	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for x64-based Systems	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 2004 for 32-bit Systems	`4566785 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 2004 for ARM64-based Systems	`4566785 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 2004 for x64-based Systems	`4566785 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 7 for 32-bit Systems Service Pack 1	`4565354 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 7 for x64-based Systems Service Pack 1	`4565354 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 8.1 for 32-bit systems	`4566425 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows 8.1 for x64-based systems	`4566425 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows RT 8.1	`4566425 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2008 for 32-bit Systems Service Pack 2	`4565353 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)	`4565353 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2008 for x64-based Systems Service Pack 2	`4565353 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)	`4565353 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2008 R2 for x64-based Systems Service Pack 1	`4565354 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)	`4565354 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2012	`4566426 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2012 (Server Core installation)	`4566426 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2012 R2	`4566425 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2012 R2 (Server Core installation)	`4566425 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2016	`4565912 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2016 (Server Core installation)	`4565912 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019	`4558997 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019 (Server Core installation)	`4558997 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 1903 (Server Core installation)	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 1909 (Server Core installation)	`4565554 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 2004 (Server Core installation)	`4566785 (Servicing Stack Update)`	Important	Elevation of Privilege	Yes

Patches

11 patches

Article	Type	Restart
`4565911`	Servicing Stack Update	Yes
`4565912`	Servicing Stack Update	Yes
`4565553`	Servicing Stack Update	Yes
`4565552`	Servicing Stack Update	Yes
`4558997`	Servicing Stack Update	Yes
`4565554`	Servicing Stack Update	Yes
`4566785`	Servicing Stack Update	Yes
`4565354`	Servicing Stack Update	Yes
`4566425`	Servicing Stack Update	Yes
`4565353`	Servicing Stack Update	Yes
`4566426`	Servicing Stack Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Zhiniang Peng (@edwardzpeng) and Fangming Gu (@afang5472), Linshuang Li

References

MSRC Advisory MITRE NVD