CVE-2020-1241 — Windows Kernel Security Feature Bypass Vulnerability

Executive Summary

A security feature bypass vulnerability exists when Windows Kernel fails to properly sanitize certain parameters. To exploit the vulnerability, a locally-authenticated attacker could attempt to run a specially crafted application on a targeted system. The update addresses the vulnerability by correcting how Windows Kernel handles parameter sanitization.

Overview

7.8

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

More Likely

MS Exploit Likelihood

Category Security Feature Bypass

Released Jun 9 2020

Last Updated Jun 9 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.03178 — 0.86389 percentile

NVD CVSS 7.8 HIGH — differs from MSRC

CVSS Vector

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

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

Required

SCOPE

Unchanged

CONFIDENTIALITY

Low

INTEGRITY

Low

AVAILABILITY

Low

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 4.8

EPSS Score

0.03178

probability of exploitation in the next 30 days

0.86389 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

22 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1607 for 32-bit Systems	`4561616 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1607 for x64-based Systems	`4561616 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1709 for 32-bit Systems	`4561602 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1709 for x64-based Systems	`4561602 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for 32-bit Systems	`4561621 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1803 for x64-based Systems	`4561621 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for 32-bit Systems	`4561608 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1809 for x64-based Systems	`4561608 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for 32-bit Systems	`4560960 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1903 for x64-based Systems	`4560960 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1909 for 32-bit Systems	`4560960 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 1909 for x64-based Systems	`4560960 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 2004 for 32-bit Systems	`4557957 (Security Update)`	Important	Security Feature Bypass	Yes
Windows 10 Version 2004 for x64-based Systems	`4557957 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2016	`4561616 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2016 (Server Core installation)	`4561616 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019	`4561608 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server 2019 (Server Core installation)	`4561608 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1803 (Server Core Installation)	`4561621 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1903 (Server Core installation)	`4560960 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 1909 (Server Core installation)	`4560960 (Security Update)`	Important	Security Feature Bypass	Yes
Windows Server, version 2004 (Server Core installation)	`4557957 (Security Update)`	Important	Security Feature Bypass	Yes

Patches

6 patches

Article	Type	Restart
`4561616`	Security Update	Yes
`4561602`	Security Update	Yes
`4561621`	Security Update	Yes
`4561608`	Security Update	Yes
`4560960`	Security Update	Yes
`4557957`	Security 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

Walied Assar

References

MSRC Advisory MITRE NVD