March 4, 2024 · Applied Cybernetics Group
CVE-2024-21338 — Microsoft Windows
known ransomware use
Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control Vulnerability
- Added to KEV
2024-03-04- Federal due date
2024-03-25- Vendor
- Microsoft
- Product
- Windows
- EPSS
- 98.8th percentile (score 0.519, as of
2026-07-13) - NVD CVSS v3.1
- —
- Ransomware use
- Known
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2024-21338
CISA short description
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.
Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.