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CVE-2024-21338

Microsoft Windows Kernel Exposed IOCTL with Insufficient Access Control

7.8 HIGHActively exploited (CISA KEV)Used in ransomwarePublic exploitEPSS 59.8%
  1. Published13 Feb 2024
  2. Added to CISA KEV4 Mar 2024
  3. Remediation due25 Mar 2024
Actively exploited (CISA KEV)

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.

Added to KEV: 4 Mar 2024Federal remediation due: 25 Mar 2024Used in ransomware

Description

Windows Kernel Elevation of Privilege Vulnerability

CVSS 3.1 breakdown

Attack vectorLocal
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Microsoft Windows 10 1809< 10.0.17763.5458
Microsoft Windows 10 21h2< 10.0.19044.4046
Microsoft Windows 10 22h2< 10.0.19045.4046
Microsoft Windows 11 21h2< 10.0.22000.2777
Microsoft Windows 11 22h2< 10.0.22621.3155
Microsoft Windows 11 23h2< 10.0.22631.3155
Microsoft Windows Server 2019< 10.0.17763.5458
Microsoft Windows Server 2022< 10.0.20348.2322
Microsoft Windows Server 2022 23h2≤ 10.0.25398.709

Remediation

Fixed in
Microsoft Windows 10 1809≥ 10.0.17763.5458
Microsoft Windows 10 21h2≥ 10.0.19044.4046
Microsoft Windows 10 22h2≥ 10.0.19045.4046
Microsoft Windows 11 21h2≥ 10.0.22000.2777
Microsoft Windows 11 22h2≥ 10.0.22621.3155
Microsoft Windows 11 23h2≥ 10.0.22631.3155
Microsoft Windows Server 2019≥ 10.0.17763.5458
Microsoft Windows Server 2022≥ 10.0.20348.2322

References

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Frequently asked

Is CVE-2024-21338 being actively exploited?

Yes. CVE-2024-21338 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 4 Mar 2024. It has been used in ransomware campaigns.

How severe is CVE-2024-21338?

CVE-2024-21338 has a CVSS 3.1 base score of 7.8, rated high. EPSS estimates a 59.8% probability of exploitation.

Which products are affected by CVE-2024-21338?

Affected products include Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 21h2, Microsoft Windows 11 22h2, and 4 more.

How do I fix CVE-2024-21338?

Upgrade affected software to a fixed version, for example Microsoft Windows 10 1809 10.0.17763.5458, Microsoft Windows 10 21h2 10.0.19044.4046, Microsoft Windows 10 22h2 10.0.19045.4046 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2024-21338 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.