Microsoft · Windows
CVE-2024-21338
Windows Kernel Elevation of Privilege Vulnerability
Exploited in attacks
Used by ransomware
High 7.8 Attack chance: 60%
What it is
Windows Kernel Elevation of Privilege Vulnerability
CISA: 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.
What to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Deadline for US federal agencies: March 25, 2024
More exploited flaws from Microsoft
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Oct 13, 2026 | Command Injection | Windows | High 8.8 | 9.8% |
| Sep 8, 2026 | Link Following | Windows | High 7.8 | 0.4% |
| Sep 8, 2026 | Heap-Based Buffer Overflow | Windows | High 7.8 | 0.4% |
| May 20, 2026 | Buffer Overflow | Windows | Critical 9.8 | 99% |
| Apr 28, 2026 | Protection Mechanism Failure | Windows | Medium 4.3 | 71% |
| Apr 13, 2026 | Out-of-Bounds Read | Windows | High 7.8 | 12% |
| Apr 13, 2026 | Link Following | Windows | High 7.8 | 4.6% |
| Feb 17, 2026 | Microsoft Windows Video ActiveX Control Remote Code Execution | Windows | High 8.8 | 77% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.