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

> Attackers can elevate privileges in Active Directory Domain Services on Windows Server, requiring immediate patching by system administrators.

- **Severity:** High 7.5 (`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`)
- **Exploited in the wild:** Yes, since 11 Apr 2022 (CISA KEV), used in ransomware
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Nov 2021
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-chp6-c7f5-h9w9

## What is CVE-2021-42278?

CVE-2021-42278 is a high-severity vulnerability in Microsoft Windows Server 2008, published on 10 Nov 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Active Directory Domain Services Elevation of Privilege Vulnerability

## Which versions are affected by CVE-2021-42278?

It affects 7 products.


Products: Microsoft Windows Server 2004, Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 20h2.

## How do I fix CVE-2021-42278?

No fix has been published for CVE-2021-42278 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 2 May 2022.

## Is CVE-2021-42278 being exploited?

Yes. Attackers have exploited CVE-2021-42278 in the wild since at least 11 Apr 2022, including in ransomware campaigns.

Public exploit code:

- Exploiting CVE-2021-42278 and CVE-2021-42287 to impersonate DA from standard domain user  (github_poc): https://github.com/safebuffer/sam-the-admin
- Exploiting CVE-2021-42278 and CVE-2021-42287 to impersonate DA from standard domain user  (github_poc): https://github.com/Ridter/noPac
- Python implementation for CVE-2021-42278 (Active Directory Privilege Escalation) (github_poc): https://github.com/ly4k/Pachine
- Exploiting CVE-2021-42278 and CVE-2021-42287 (github_poc): https://github.com/waterrr/noPac
- Detection script for CVE-2021-42278 and CVE-2021-42287 (github_poc): https://github.com/cybersecurityworks553/noPac-detection
- Go implementation of NoPac, exploiting CVE-2021-42278 and CVE-2021-42287 (github_poc): https://github.com/xLTJ/noPac

## Other vulnerabilities in Microsoft Windows Server 2008

- [CVE-2021-42287](https://insights.sbomify.com/CVE-2021-42287/): Microsoft Active Directory Domain Services Privilege Escalation (high 7.5, exploited in the wild)
- [CVE-2021-36942](https://insights.sbomify.com/CVE-2021-36942/): Microsoft Windows Local Security Authority (LSA) Spoofing (high 7.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42278 and fix it if it is affected.

What it is: CVE-2021-42278 is a high-severity vulnerability in Microsoft Windows Server 2008, published on 10 Nov 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2021-42278 in the wild since at least 11 Apr 2022, including in ransomware campaigns.

Affected product: Microsoft Windows Server 2008. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-42278/ (Markdown: https://insights.sbomify.com/CVE-2021-42278/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42278
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42278
- OSV: https://osv.dev/vulnerability/CVE-2021-42278

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42278/
Summaries are generated and may contain mistakes; the official description above is the record.