CVE-2021-42287
HighExploitedPublic exploitActive Directory Domain Services Elevation of Privilege Vulnerability
Published Nov 9, 2021 · Updated Aug 19, 2026
Key Facts
Patch immediately- CVE-2021-42287 is a high-severity vulnerability (CVSS 8.8 v3.1) affecting Windows Server 2004 (Microsoft), windows server 2008 R2 (Microsoft), Windows Server 2008 (Microsoft) and 17 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Apr 11, 2022 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 77% probability of exploitation in the next 30 days.
- Fixed versions are available, including Windows Server 2004 10.0.19041.1348, windows server 2008 R2 6.1.7601.25769, Windows Server 2008 Sp2 6.0.6003.21282.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
8.8
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
77%
Higher than 99.5% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-42287 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Active Directory Domain Services Elevation of Privilege Vulnerability
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Apr 11, 2022 | May 2, 2022 | Known |
| Industry KEV feed | Apr 11, 2022 | May 2, 2022 | Known |
| CIRCL KEV | Apr 11, 2022 | May 2, 2022 | Known |
| ENISA EUVD | Apr 11, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
40 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows Server 2004Microsoft | 10.0.19041.1348 | 10.0.19041.1348 |
| windows server 2008 R2Microsoft | 6.1.7601.25769 | 6.1.7601.25769 |
| Windows Server 2008Microsoft | r2-sp1 | n/a |
| Windows Server 2008 Sp2Microsoft | 6.0.6003.21282 | 6.0.6003.21282 |
| Windows Server 2012Microsoft | 6.2.9200.23517, r2, >= 6.2.9200.0 | 6.2.9200.23517 |
Patched Releases
Windows Server 2004
10.0.19041.1348
windows server 2008 R2
6.1.7601.25769
Windows Server 2008 Sp2
6.0.6003.21282
Windows Server 2012
6.2.9200.23517
windows server 2012 R2
6.3.9600.20174
Windows Server 2016
10.0.14393.4770
Windows Server 2019
10.0.17763.2300
Windows Server 2022
10.0.20348.350
windows server 20H2
10.0.19042.1348, 10.0.19041.1348
Windows Server 2008 R2 Service Pack 1
6.1.7601.25769
Windows Server 2008 R2 Service Pack 1 (Server Core installation)
6.1.7601.25769
Windows Server 2008 Service Pack 2
6.0.6003.21282
Windows Server 2008 Service Pack 2 (Server Core installation)
6.0.6003.21282
Windows Server 2012 (Server Core installation)
6.2.9200.23517
Windows Server 2012 R2 (Server Core installation)
6.3.9600.20174
Windows Server 2016 (Server Core installation)
10.0.14393.4770
Windows Server 2019 (Server Core installation)
10.0.17763.2300
Windows Server version 2004
10.0.19041.1348
Windows Server version 20H2
10.0.19041.1348
Timeline
Publicly disclosed
Nov 9, 2021
Added to CISA KEV
Apr 11, 2022
Added to Industry KEV feed
Apr 11, 2022
Added to CIRCL KEV
Apr 11, 2022
Added to ENISA EUVD
Apr 11, 2022
Last updated
Aug 19, 2026
References
- patchhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42287
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Active Directory Domain Services Elevation of Privilege Vulnerability
Affected: Windows Server 2004 (Microsoft) versions 10.0.19041.1348; windows server 2008 R2 (Microsoft) versions 6.1.7601.25769; Windows Server 2008 (Microsoft) versions r2-sp1, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Apr 11, 2022 and is known to be used in ransomware campaigns.
Yes. It was added on Apr 11, 2022 with a federal remediation due date of May 2, 2022.
Public exploit code is available.
Fixed versions are available, including Windows Server 2004 10.0.19041.1348, windows server 2008 R2 6.1.7601.25769, Windows Server 2008 Sp2 6.0.6003.21282.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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