Is CVE-2024-21338 in the CISA KEV catalog?

Yes. CVE-2024-21338 is on the CISA Known Exploited Vulnerabilities list, added 2024-03-04, and has known ransomware campaign use.

What is the CVSS severity of CVE-2024-21338?

CVE-2024-21338 has a CVSS v3 base score of 7.8 (HIGH).

What is the EPSS score for CVE-2024-21338?

CVE-2024-21338 has an EPSS score of 51.87% (99th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2024-21338?

Install KB5034768 for Windows 10 Version 1809. Fixes are available for 11 affected products.

CVE & CISA-KEV Catalog

CVE-2024-21338

HIGHCISA KEVEPSS 99th pctl

7.8

CVSS v3

NVD

Description

Windows Kernel Elevation of Privilege Vulnerability

CWE-822Untrusted Pointer Dereference

How to fix

Remediation Available

Windows 10 Version 1809Windows

Install:KB5034768Microsoft

Windows 10 Version 21H2Windows

Install:KB5034763Microsoft

Windows 10 Version 22H2Windows

Install:KB5034763Microsoft

Windows 11 Version 22H2Windows

Install:KB5034765Microsoft

Windows 11 Version 23H2Windows

Install:KB5034765Microsoft

Windows 11 version 21H2Windows

Install:KB5034766Microsoft

Windows Server 2019Windows

Install:KB5034768Microsoft

Windows Server 2019 (Server Core installation)Windows

Install:KB5034768Microsoft

Windows Server 2022Windows

Install:KB5034770Microsoft

Windows Server 2022 (Server Core installation)Windows

Install:KB5034770Microsoft

Windows Server 2022, 23H2 Edition (Server Core installation)Windows

Install:KB5034769Microsoft

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

51.87%probability of exploitation in 30 days

99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control Vulnerability

Microsoft Windows Kernel contains an exposed IOCTL with insufficient access control vulnerability within the IOCTL (input and output control) dispatcher in appid.sys that allows a local attacker to achieve privilege escalation.

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Remediation due: 2024-03-25

Associated with ransomware campaigns

References

Patch1

msrc.microsoft.com

Exploit3

Government Resource1

cisa.gov

Related Vulnerabilities

Other CWE-822 (Untrusted Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-21768	High	7.8	65%	-	Fix
CVE-2024-35250	High	7.8	25%	KEV	Fix
CVE-2023-29360	High	8.4	22%	KEV	Fix
CVE-2023-36033	High	7.8	12%	KEV	Fix
CVE-2019-13334	High	7.8	6.8%	-	-
CVE-2018-17893	Critical	9.8	6.4%	-	-

Embed a live status badge for CVE-2024-21338

Markdown

[![CVE-2024-21338](https://tridentstack.com/cve/badge/CVE-2024-21338.svg)](https://tridentstack.com/cve/CVE-2024-21338)

HTML

<a href="https://tridentstack.com/cve/CVE-2024-21338"><img src="https://tridentstack.com/cve/badge/CVE-2024-21338.svg" alt="CVE-2024-21338"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-28.