# CVE-2024-21338: Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control

> An attacker can exploit a flaw in the Windows Kernel to elevate privileges, requiring a security patch from Microsoft.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C`)
- **Exploited in the wild:** Yes, since 4 Mar 2024 (CISA KEV), used in ransomware
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Feb 2024
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-jqrq-gqwg-r8r5

## What is CVE-2024-21338?

CVE-2024-21338 is a high-severity vulnerability in Microsoft Windows 10 1809, published on 13 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Windows Kernel Elevation of Privilege Vulnerability

Weakness: CWE-822 (Untrusted Pointer Dereference)

## Which versions are affected by CVE-2024-21338?

It affects 9 products.


Products: Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 21h2, Microsoft Windows 11 22h2, Microsoft Windows 11 23h2, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2.

## How do I fix CVE-2024-21338?

No fix has been published for CVE-2024-21338 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 25 Mar 2024.

## Is CVE-2024-21338 being exploited?

Yes. Attackers have exploited CVE-2024-21338 in the wild since at least 4 Mar 2024, including in ransomware campaigns.

Public exploit code:

- Local Privilege Escalation from Admin to Kernel vulnerability on Windows 10 and Windows 11 operating systems with HVCI enabled. (github_poc): https://github.com/hakaioffsec/CVE-2024-21338
- Windows AppLocker Driver (appid.sys) LPE (github_poc): https://github.com/Crowdfense/CVE-2024-21338
- https://github.com/tykawaii98/CVE-2024-21338_PoC (github_poc): https://github.com/tykawaii98/CVE-2024-21338_PoC
- https://github.com/MistyFir/CVE-2024-21338-Exploit (github_poc): https://github.com/MistyFir/CVE-2024-21338-Exploit
- Local Privilege Escalation from Admin to Kernel vulnerability on Windows 10 and Windows 11 operating systems with HVCI enabled. (github_poc): https://github.com/Zombie-Kaiser/CVE-2024-21338-x64-build-
- Fork of https://github.com/hakaioffsec/CVE-2024-21338 (github_poc): https://github.com/UMU618/CVE-2024-21338

## Other vulnerabilities in Microsoft Windows 10 1809

- [CVE-2024-29988](https://insights.sbomify.com/CVE-2024-29988/): Microsoft SmartScreen Prompt Security Feature Bypass (high 8.8, exploited in the wild)
- [CVE-2024-21412](https://insights.sbomify.com/CVE-2024-21412/): Microsoft Windows Internet Shortcut Files Security Feature Bypass (high 8.1, exploited in the wild)
- [CVE-2025-62221](https://insights.sbomify.com/CVE-2025-62221/): Microsoft Windows Use After Free (high 7.8, exploited in the wild)
- [CVE-2025-30400](https://insights.sbomify.com/CVE-2025-30400/): Microsoft Windows DWM Core Library Use-After-Free (high 7.8, exploited in the wild)
- [CVE-2023-36033](https://insights.sbomify.com/CVE-2023-36033/): Microsoft Windows Desktop Window Manager (DWM) Core Library Privilege Escalation (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-21338 and fix it if it is affected.

What it is: CVE-2024-21338 is a high-severity vulnerability in Microsoft Windows 10 1809, published on 13 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2024-21338 in the wild since at least 4 Mar 2024, including in ransomware campaigns.

Affected product: Microsoft Windows 10 1809. 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-2024-21338/ (Markdown: https://insights.sbomify.com/CVE-2024-21338/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21338
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21338
- OSV: https://osv.dev/vulnerability/CVE-2024-21338

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21338/
Summaries are generated and may contain mistakes; the official description above is the record.