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High 7.5Known exploited (CISA KEV)Published Nov 10, 2021
CVE-2021-42278Active Directory Domain Services Elevation of Privilege Vulnerability
Updated under an hour ago ()
Does this affect you?
It affects Microsoft Windows Server 2008 R2 Service Pack 1 and 13 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Apr 11, 2022; federal agencies had to remediate by May 2, 2022, and it is known to be used in ransomware. Treat that date as your deadline.
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Active Directory Domain Services Elevation of Privilege Vulnerability
- CVSS
- 7.5 HIGH (v3.1, CNA)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
- Weakness (CWE)
- Not given
- Known exploited
- Added to CISA KEV Apr 11, 2022; federal remediation due May 2, 2022; known ransomware useApply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 73.30% (percentile 99)
- Assigned by
- microsoft
- NVD analysis
- Analyzed
- Record last updated
- Aug 19, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Microsoft Windows Server 2008 R2 Service Pack 1 microsoft:windows_server_2008_r2_service_pack_1 (from the name) | from 6.1.7601.0 before 6.1.7601.25769 | CNA record |
Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation) microsoft:windows_server_2008_r2_service_pack_1_server_core_installation (from the name) | from 6.1.7601.0 before 6.1.7601.25769 | CNA record |
Microsoft Windows Server 2008 Service Pack 2 microsoft:windows_server_2008_service_pack_2 (from the name) | from 6.0.6003.0 before 6.0.6003.21282 | CNA record |
Microsoft Windows Server 2008 Service Pack 2 (Server Core installation) microsoft:windows_server_2008_service_pack_2_server_core_installation (from the name) | from 6.0.6003.0 before 6.0.6003.21282 | CNA record |
Microsoft Windows Server 2012 microsoft:windows_server_2012 (from the name) | from 6.2.9200.0 before 6.2.9200.23517 | CNA record |
Microsoft Windows Server 2012 R2 microsoft:windows_server_2012_r2 (from the name) | from 6.3.9600.0 before 6.3.9600.20174 | CNA record |
Microsoft Windows Server 2016 microsoft:windows_server_2016 (from the name) | from 10.0.14393.0 before 10.0.14393.4770 | CNA record |
Microsoft Windows Server 2019 microsoft:windows_server_2019 (from the name) | from 10.0.17763.0 before 10.0.17763.2300 | CNA record |
Microsoft Windows Server 2022 microsoft:windows_server_2022 (from the name) | from 10.0.20348.0 before 10.0.20348.350 | CNA record |
Microsoft Windows Server version 2004 microsoft:windows_server_version_2004 (from the name) | from 10.0.0 before 10.0.19041.1348 | CNA record |
Microsoft Windows Server version 20H2 microsoft:windows_server_version_20h2 (from the name) | from 10.0.0 before 10.0.19042.1348 | CNA record |
microsoft windows_server_2004 microsoft:windows_server_2004 | before 10.0.19041.1348 | NVD |
microsoft windows_server_2008 microsoft:windows_server_2008 | all versions; r2 | NVD |
microsoft windows_server_2012 microsoft:windows_server_2012 | all versions; r2 | NVD |
microsoft windows_server_2016 microsoft:windows_server_2016 | before 10.0.14393.4770 | NVD |
microsoft windows_server_2019 microsoft:windows_server_2019 | before 10.0.17763.2300 | NVD |
microsoft windows_server_2022 microsoft:windows_server_2022 | before 10.0.20348.350 | NVD |
microsoft windows_server_20h2 microsoft:windows_server_20h2 | before 10.0.19042.1348 | NVD |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42278vendor-advisory, patch
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42278patch, vendor-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42278us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.