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

What it is

Windows Kernel Elevation of Privilege Vulnerability

Exploitation evidence

First exploit evidence seen: 2024-03-04 (earliest date across the sources below).

Exploited in the wild

• CISA KEV: listed since 2024-03-04. Source

Public exploit code

Exploit-DB

• EDB-51946: Microsoft Windows 10.0.17763.5458 - Kernel Privilege Escalation (2024-04-02)
• EDB-52275: Microsoft Windows 11 - Kernel Privilege Escalation (2025-04-22)

GitHub proof-of-concept repositories

9 public repositories from 9 accounts, first seen 2024-04-13. Most starred: hakaioffsec/CVE-2024-21338 (333 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · Exploit-DB (OffSec) · nomi-sec/PoC-in-GitHub.

How to fix it

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. (source: CISA KEV)

Fixed versions

• microsoft windows 10 1809: upgrade to 10.0.17763.5458 or later
• microsoft windows 10 21h2: upgrade to 10.0.19044.4046 or later
• microsoft windows 10 22h2: upgrade to 10.0.19045.4046 or later
• microsoft windows 11 21h2: upgrade to 10.0.22000.2777 or later
• microsoft windows 11 22h2: upgrade to 10.0.22621.3155 or later
• microsoft windows 11 23h2: upgrade to 10.0.22631.3155 or later
• microsoft windows server 2019: upgrade to 10.0.17763.5458 or later
• microsoft windows server 2022: upgrade to 10.0.20348.2322 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338 (CISA KEV notes)

MITRE ATT&CK mitigations for this chain

• M1051 Update Software (for T1068) : Update software regularly by employing patch management for internal enterprise endpoints and servers.
• M1050 Exploit Protection (for T1068) : Security applications that look for behavior used during exploitation such as Windows Defender Exploit Guard (WDEG) and the Enhanced Mitigation Experience Toolkit (EMET) can be used to mitigate some exploitation behavior. Control flow integrity checking is another way to potentially identify and stop a software exploi
• M1048 Application Isolation and Sandboxing (for T1068) : Make it difficult for adversaries to advance their operation through exploitation of undiscovered or unpatched vulnerabilities by using sandboxing. Other types of virtualization and application microsegmentation may also mitigate the impact of some types of exploitation. Risks of additional exploits and weaknesses in t
• M1019 Threat Intelligence Program (for T1068) : Develop a robust cyber threat intelligence capability to determine what types and levels of threat may use software exploits and 0-days against a particular organization.
• M1038 Execution Prevention (for T1068) : Consider blocking the execution of known vulnerable drivers that adversaries may exploit to execute code in kernel mode. Validate driver block rules in audit mode to ensure stability prior to production deployment.

Detection Generic guidance

• Privilege Escalation: Alert on processes gaining SYSTEM/root unexpectedly, and on exploitation crashes of privileged services.

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.