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CVE-2024-21338VulnerabilityAdded to KEV 03/04/2024

CVE-2024-21338: Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control Vulnerability

Affects Microsoft WindowsSource CISA KEV

0

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

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
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:C

What to do

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public exploits and detection

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

References

Community reviews

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