CVE-2024-21338: Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control Vulnerability
Affects Microsoft WindowsSource CISA KEV
Exploited in the wild · used in ransomware campaigns · KEV due 25 Mar 2024 · public exploit available (Exploit-DB) · 59% EPSS : apply the vendor's fix or mitigations to Microsoft Windows now.
Data as of 10/24/2026, 22:15:59 UTC
- Exploitation
Actively exploited – in CISA KEV since 03/04/2024
- KEV deadline
- 03/25/2024 US federal agencies must patch by this date; a sensible deadline for everyone else.
- Ransomware
- Used in ransomware campaigns
- EPSS
- 59.8% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Public exploits
- 2 Exploit-DB entriesPublic attack or detection tooling exists; see Public exploits below.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:CWhat to do
CISA required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Public exploits and detection
Exploit-DB
Public tooling indexed from Metasploit Framework, Exploit-DB and ProjectDiscovery nuclei-templates. Its existence raises the odds of exploitation; it does not confirm attacks.
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.
Weaknesses
- CWE-822Untrusted Pointer Dereference (opens in a new tab)
Base weakness
The product obtains a value from an untrusted source, converts this value to a pointer, and dereferences the resulting pointer.