CVE-2020-0665 — Active Directory Elevation of Privilege Vulnerability

Executive Summary

An elevation of privilege vulnerability exists in the way Active Directory handles information for domains in a transitively trusted forest. To exploit this vulnerability, an attacker would first need to compromise a transitively trusted Active Directory forest. An attacker who successfully exploited this vulnerability could obtain administrative rights on a computer in a domain which trusts the Active Directory forest under the attacker's control. This update addresses the vulnerability by correcting how Active Directory handles information for domains in transitively trusted forests.

Overview

8.1

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Released Feb 11 2020

Last Updated Feb 11 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.04382 — 0.90436 percentile

NVD CVSS 8.1 HIGH — differs from MSRC

CVSS Vector

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

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

None

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: 5.9

EPSS Score

0.04382

probability of exploitation in the next 30 days

0.90436 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

27 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 for 32-bit Systems	`4537776 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 for x64-based Systems	`4537776 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1607 for 32-bit Systems	`4537764 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1607 for x64-based Systems	`4537764 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1709 for 32-bit Systems	`4537789 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1709 for ARM64-based Systems	`4537789 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1709 for x64-based Systems	`4537789 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1803 for 32-bit Systems	`4537762 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1803 for ARM64-based Systems	`4537762 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1803 for x64-based Systems	`4537762 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for 32-bit Systems	`4532691 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for ARM64-based Systems	`4532691 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for x64-based Systems	`4532691 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1903 for 32-bit Systems	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1903 for ARM64-based Systems	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1903 for x64-based Systems	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for 32-bit Systems	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for ARM64-based Systems	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for x64-based Systems	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 7 for 32-bit Systems Service Pack 1 4537820 (Monthly Rollup) 4537813 (Security Only) Important Elevation of Privilege 4534310 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537813 Windows 7 for x64-based Systems Service Pack 1 4537820 (Monthly Rollup) 4537813 (Security Only) Important Elevation of Privilege 4534310 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537813 Windows 8.1 for 32-bit systems 4537821 (Monthly Rollup) 4537803 (Security Only) Important Elevation of Privilege 4534297 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows 8.1 for x64-based systems 4537821 (Monthly Rollup) 4537803 (Security Only) Important Elevation of Privilege 4534297 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows RT 8.1	`4537821 (Monthly Rollup)`	Important	Elevation of Privilege	Yes
Windows Server 2008 for 32-bit Systems Service Pack 2 4537810 (Monthly Rollup) 4537822 (Security Only) Important Elevation of Privilege 4534303 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 4537810 (Monthly Rollup) 4537822 (Security Only) Important Elevation of Privilege 4534303 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Windows Server 2008 for x64-based Systems Service Pack 2 4537810 (Monthly Rollup) 4537822 (Security Only) Important Elevation of Privilege 4534303 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 4537810 (Monthly Rollup) 4537822 (Security Only) Important Elevation of Privilege 4534303 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes None Windows Server 2008 R2 for x64-based Systems Service Pack 1 4537820 (Monthly Rollup) 4537813 (Security Only) Important Elevation of Privilege 4534310 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537813 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4537820 (Monthly Rollup) 4537813 (Security Only) Important Elevation of Privilege 4534310 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537813 Windows Server 2012 4537814 (Monthly Rollup) 4537794 (Security Only) Important Elevation of Privilege 4534283 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537814 4537794 Windows Server 2012 (Server Core installation) 4537814 (Monthly Rollup) 4537794 (Security Only) Important Elevation of Privilege 4534283 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537814 4537794 Windows Server 2012 R2 4537821 (Monthly Rollup) 4537803 (Security Only) Important Elevation of Privilege 4534297 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows Server 2012 R2 (Server Core installation) 4537821 (Monthly Rollup) 4537803 (Security Only) Important Elevation of Privilege 4534297 Base: 6.6 Temporal: 5.9 Vector: CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Yes 4537821 4537803 4537821 Windows Server 2016	`4537764 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2016 (Server Core installation)	`4537764 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019	`4532691 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019 (Server Core installation)	`4532691 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 1803 (Server Core Installation)	`4537762 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 1903 (Server Core installation)	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 1909 (Server Core installation)	`4532693 (Security Update)`	Important	Elevation of Privilege	Yes

Patches

7 patches

Article	Type	Restart
`4537776`	Security Update	Yes
`4537764`	Security Update	Yes
`4537789`	Security Update	Yes
`4537762`	Security Update	Yes
`4532691`	Security Update	Yes
`4532693`	Security Update	Yes
`4537821`	Monthly Rollup	Yes

Exploits & PoC

1 public PoC

Unverified third-party code

Public proof-of-concept repositories aggregated from PoC-in-GitHub. They are not reviewed and may be incomplete, non-functional, or malicious — inspect the code before running anything.

Repository	Stars	Published	Description
gunzf0x/CVE-2020-0665	1	2025-04-16	Proof of Concept for CVE-2020-0665, a.k.a. SID Filter Bypass.

Detection Rules

No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.

Acknowledgments

Dirk-jan Mollema ( @_dirkjan

References

MSRC Advisory MITRE NVD