# CVE-2021-42278: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability

Source: https://junglewise.ai/threats/cve-2021-42278-microsoft-active-directory-domain-services-privilege-escalation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-04-11. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2021-42278 · Severity: critical · CVSS 7.5 · Exploited in the wild · Published 2022-04-11

Microsoft Active Directory Domain Services contains an elevation of privilege vulnerability. An authenticated attacker can exploit this flaw to escalate privileges within a domain environment. This vulnerability has been observed being exploited in the wild.

Technologies: [Microsoft Active Directory](https://junglewise.ai/threats/technologies/active-directory). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2021-42278 exploited in the wild?** Yes. CVE-2021-42278 is known to be exploited in the wild, first recorded on 11 April 2022. Treat it as urgent.

**How severe is CVE-2021-42278?** Critical severity, with a CVSS score of 7.5, published 11 April 2022.

**Which products and versions are affected?** Microsoft Windows Server 2008 SP2, R2 SP1; Microsoft Windows Server 2012 R2; Microsoft Windows Server 2016 up to (excluding) 10.0.14393.4770; Microsoft Windows Server 2019 up to (excluding) 10.0.17763.2300; and 3 more.

**Is there a fix for CVE-2021-42278?** A patch was published on 2022-05-02: Due date for remediation per CISA BOD 22-01 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2021-42278 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2021-42278?** Check whether you run Microsoft Active Directory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Microsoft Windows Server 2008 SP2, R2 SP1
- Microsoft Windows Server 2012 R2
- Microsoft Windows Server 2016 up to (excluding) 10.0.14393.4770
- Microsoft Windows Server 2019 up to (excluding) 10.0.17763.2300
- Microsoft Windows Server 2022 up to (excluding) 10.0.20348.350
- Microsoft Windows Server 2004 up to (excluding) 10.0.19041.1348
- Microsoft Windows Server 20H2 up to (excluding) 10.0.19042.1348

## Timeline

- 2021-11-09: disclosed: NVD Published Date
- 2022-04-11: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2022-05-02: patched: Due date for remediation per CISA BOD 22-01

## Related threats

- [Microsoft Windows Active Directory infinite loop denial of service](https://junglewise.ai/threats/cve-2026-54119-microsoft-windows-active-directory-infinite-loop-denial-of)
- [Microsoft Active Directory Domain Services Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2022-26923-microsoft-active-directory-domain-services-privilege-escalation)
- [Microsoft Active Directory Domain Services Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2021-42287-microsoft-active-directory-domain-services-privilege-escalation)