What is CVE-2024-21338?
Windows Kernel Elevation of Privilege Vulnerability
The record classifies CVE-2024-21338 under weakness classes CWE-822, NVD-CWE-noinfo. Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 9 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 965 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.8 — HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 79.1% probability of exploitation in the next 30 days, higher than 99.0% of all scored CVEs
- CISA KEV
- Listed since 2024-03-04, federal remediation deadline 2024-03-25 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2024-02-13, last modified 2025-10-28
Is CVE-2024-21338 being exploited?
CISA added CVE-2024-21338 to the Known Exploited Vulnerabilities catalog on 2024-03-04, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2024-03-25 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.
Affected products and versions
- Microsoft: Windows 10 1809, Windows 10 21h2, Windows 10 22h2, Windows 11 21h2, Windows 11 22h2, Windows 11 23h2, Windows Server 2019, Windows Server 2022, Windows Server 2022 23h2
How to fix CVE-2024-21338
The record marks a vendor fix as available for CVE-2024-21338. Patch reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338. Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21338. Because CVE-2024-21338 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2024-03-25. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2024-21338
1 tracked threat in the Threadlinqs corpus references CVE-2024-21338, either in the campaign’s CVE list or as an indicator on the campaign record.
- LABYRINTH CHOLLIMA Evolves into Three DPRK Adversaries — CRITICAL · 2026-02-12
Sources
Seeded from kev and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.