Microsoft · Active Directory
CVE-2021-42278
Active Directory Domain Services Elevation of Privilege Vulnerability
Exploited in attacks
Used by ransomware
High 7.5 Attack chance: 73%
What it is
Active Directory Domain Services Elevation of Privilege Vulnerability
CISA: Microsoft Active Directory Domain Services contains an unspecified vulnerability that allows for privilege escalation.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: May 2, 2022
More exploited flaws from Microsoft
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Aug 18, 2022 | Domain Services Privilege Escalation | Active Directory | High 8.8 | 84% |
| Apr 11, 2022 | Domain Services Privilege Escalation | Active Directory | High 7.5 | 77% |
| Oct 13, 2026 | Command Injection | Windows | High 8.8 | 9.8% |
| Sep 25, 2026 | Code Injection | SharePoint | High 8.8 | 8.2% |
| Sep 8, 2026 | Link Following | Windows | High 7.8 | 0.4% |
| Sep 8, 2026 | Heap-Based Buffer Overflow | Windows | High 7.8 | 0.4% |
| Aug 26, 2026 | Remote Code Execution | SQL Server | High 8.8 | 57% |
| Aug 18, 2026 | Double Free | Internet Key Exchange (IKE) Service Extensions | Critical 9.8 | 77% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.