CVE-2021-42278 — Active Directory Domain Services Elevation of Privilege Vulnerability

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 Nov 9 2021

Last Updated Nov 9 2021

Publicly Disclosed No

CISA KEV Listed (added 2022-04-11)

Known Exploits None Known

EPSS Score 0.70207 — 0.99323 percentile

NVD CVSS 7.5 HIGH — matches MSRC

CVSS Vector

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

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.5

EPSS Score

0.70207

probability of exploitation in the next 30 days

0.99323 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

8 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows Server 2008 for 32-bit Systems Service Pack 2 5007263 (Monthly Rollup) 5007246 (Security Only) Important Elevation of Privilege 5006736 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21282 Yes 5007263 5007246 Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 5007263 (Monthly Rollup) 5007246 (Security Only) Important Elevation of Privilege 5006736 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21282 Yes 5007263 5007246 Windows Server 2008 for x64-based Systems Service Pack 2 5007263 (Monthly Rollup) 5007246 (Security Only) Important Elevation of Privilege 5006736 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21282 Yes 5007263 5007246 Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 5007263 (Monthly Rollup) 5007246 (Security Only) Important Elevation of Privilege 5006736 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.0.6003.21282 Yes 5007263 5007246 Windows Server 2008 R2 for x64-based Systems Service Pack 1 5007236 (Monthly Rollup) 5007233 (Security Only) Important Elevation of Privilege 5006743 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.25769 Yes 5007236 5007233 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 5007236 (Monthly Rollup) 5007233 (Security Only) Important Elevation of Privilege 5006743 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.1.7601.25769 Yes 5007236 5007233 Windows Server 2012 5007260 (Monthly Rollup) 5007245 (Security Only) Important Elevation of Privilege 5006739 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.2.9200.23517 Yes 5007260 5007245 Windows Server 2012 (Server Core installation) 5007260 (Monthly Rollup) 5007245 (Security Only) Important Elevation of Privilege 5006739 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.2.9200.23517 Yes 5007260 5007245 Windows Server 2012 R2 5007247 (Monthly Rollup) 5007255 (Security Only) Important Elevation of Privilege 5006714 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.3.9600.20174 Yes 5007247 5007255 Windows Server 2012 R2 (Server Core installation) 5007247 (Monthly Rollup) 5007255 (Security Only) Important Elevation of Privilege 5006714 Base: 7.5 Temporal: 6.5 Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C 6.3.9600.20174 Yes 5007247 5007255 Windows Server 2016	`5007192 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2016 (Server Core installation)	`5007192 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019	`5007206 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019 (Server Core installation)	`5007206 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022	`5007205 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022 (Server Core installation)	`5007205 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 2004 (Server Core installation)	`5007186 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server, version 20H2 (Server Core Installation)	`5007186 (Security Update)`	Important	Elevation of Privilege	Yes

Patches

4 patches

Article	Type	Restart
`5007192`	Security Update	Yes
`5007206`	Security Update	Yes
`5007205`	Security Update	Yes
`5007186`	Security Update	Yes

Exploits & PoC

6 public PoCs

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
safebuffer/sam-the-admin	1067	2021-12-11	Exploiting CVE-2021-42278 and CVE-2021-42287 to impersonate DA from standard domain user
Ridter/noPac	1021	2021-12-13	Exploiting CVE-2021-42278 and CVE-2021-42287 to impersonate DA from standard domain user
ly4k/Pachine	277	2021-12-13	Python implementation for CVE-2021-42278 (Active Directory Privilege Escalation)
waterrr/noPac	6	2021-12-13	Exploiting CVE-2021-42278 and CVE-2021-42287
cybersecurityworks553/noPac-detection	2	2021-12-27	Detection script for CVE-2021-42278 and CVE-2021-42287
xLTJ/noPac	0	2026-07-07	Go implementation of NoPac, exploiting CVE-2021-42278 and CVE-2021-42287

Detection Rules

Detection available

Community detection & vulnerability-scanning rules aggregated from Sigma and Nuclei templates. Validate and tune to your environment before deploying.

Sigma rules 2

Win Susp Computer Name Containing Samtheadmin critical Potential CVE-2021-42278 Exploitation Attempt medium

Acknowledgments

Andrew Bartlett of Catalyst IT

References

MSRC Advisory MITRE NVD