CVE-2021-42287: Active Directory Domain Services Elevation of Privilege Vulnerability

Overview

Severity
High (CVSS 7.5)
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
Category
Elevation of Privilege
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2021-Nov
Released
2021-11-09
EPSS Score
94.01% (percentile: 99.9%)
CISA KEV
Listed — due 2022-05-02

FAQ

Where can I find more information about the improved authentication process added by the update for CVE-2021-42287? See Authentication updates.

Known Exploits (5)

  • Microsoft Active Directory Domain Services Privilege Escalation Vulnerability — added 2022-04-01T09:10:14Z
  • Microsoft Active Directory Domain Services Privilege Escalation Vulnerability — added 2021-12-13T19:01:18Z
  • Microsoft Active Directory Domain Services Privilege Escalation Vulnerability — added 2021-12-13T15:24:59Z
  • Microsoft Active Directory Domain Services Privilege Escalation Vulnerability — added 2021-12-13T10:28:12Z
  • Microsoft Active Directory Domain Services Privilege Escalation Vulnerability — added 2021-12-11T15:10:30Z

Detection & Weaponization (2 sources)

Maturity: Detection

  • Sigma rules: Suspicious Computer Account Name Change CVE-2021-42287, Potential CVE-2021-42287 Exploitation Attempt
  • GitHub PoC: 5 repositories

Affected Products (18)

Windows

  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows Server, version 2004 (Server Core installation)
  • Windows Server, version 20H2 (Server Core Installation)
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)

ESU

  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Security Updates (12)

Acknowledgments

Andrew Bartlett of Catalyst IT

Revision History

  • 2021-11-09: Information published.