CVE-2024-21338
Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 25 March 2024). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
Windows Kernel Elevation of Privilege Vulnerability
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 59.81% probability · 99th percentile
- Public exploits
- 2 in Exploit-DB · first 2 April 2024
- CISA KEV
- Listed 4 March 2024 · due 25 March 2024 · used in ransomware campaigns
- Weakness
- CWE-822
- Affected
- 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
- Source
- secure@microsoft.com
EPSS 59.8% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338; https://nvd.nist.gov/vuln/detail/CVE-2024-21338
Public exploits (2)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338Patch, Vendor Advisory
- https://decoded.avast.io/janvojtesek/lazarus-and-the-fudmodule-rootkit-beyond-byovd-with-an-admin-to-kernel-zero-day/Exploit, Technical Description, Third Party Advisory
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338Patch, Vendor Advisory
- https://packetstorm.news/files/id/190586/Exploit, VDB Entry
- https://www.exploit-db.com/exploits/52275Exploit, VDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21338US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.