CVE-2024-21338
Published: March 4, 2024
Official 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.
CISA KEV Advisory
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.
Risk Analysis
A vulnerability in the Microsoft Windows Kernel's IOCTL dispatcher (appid.sys) allows a local attacker to achieve privilege escalation. This is a high-severity flaw with an EPSS score of 0.77254, indicating a high likelihood of exploitation, and it is confirmed to be exploited in the wild.
This vulnerability is actively exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities Catalog. Exploitation requires local access to the system to achieve privilege escalation.
Install the latest security updates from Microsoft for Windows to patch this kernel vulnerability. Implement the principle of least privilege for all user accounts to limit the impact of successful exploitation.
Technical Analysis
CVE-2024-21338 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2024-21338 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2024-21338 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1