⚠ Actively exploited
Added to CISA KEV on 2025-01-14. Federal agencies required to patch by 2025-02-04. Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable..

CVE-2025-21334 — Use After Free in Microsoft Windows 10 Version 21h2

CWE-416 — Use After FreeCWE-668 — Resource Exposure15 documents10 sources
Severity
7.8HIGHNVD
EPSS
6.6%
top 8.78%
CISA KEV
KEV
Added 2025-01-14
Due 2025-02-04
Exploit
No known exploits
Affected products
27
Microsoft Windows 10 Version 21h2Microsoft Windows 10 Version 22h2Microsoft Windows 11 Version 22h2+24 more
Timeline
PublishedJan 14
KEV addedJan 14
KEV dueFeb 4
Latest updateApr 18
CISA Required Action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Description

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9

Affected Packages27 packages

▶NVDmicrosoft/windows< 10.0.25398.1369+1
▶NVDmicrosoft/windows_10_21h2< 10.0.19044.5371
▶NVDmicrosoft/windows_10_22h2< 10.0.19045.5371
▶NVDmicrosoft/windows_11_22h2< 10.0.22621.4751
▶NVDmicrosoft/windows_11_23h2< 10.0.22631.4751

Patches

Patch: msrc.microsoft.com ↗

🔴Vulnerability Details

2
GHSA
GHSA-3hcq-fqcw-cvgf: Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability↗2025-01-14
▶
VulnCheck
Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability↗2025
▶

📋Vendor Advisories

3
CISA
Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability↗2025-01-14
▶
Microsoft
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability↗2025-01-14
▶
Microsoft
environment variable leak↗2021-03-09
▶

🕵️Threat Intelligence

9
Qualys
Zero-Day Vulnerability Protection | Detect &amp; Stop Threats | Qualys↗2025-04-18
▶
Qualys
Zero-Day Vulnerability Protection | Detect & Stop Threats | Qualys↗2025-04-18
▶
Bleepingcomputer
Microsoft January 2025 Patch Tuesday fixes 8 zero-days, 159 flaws↗2025-01-14
▶
Krebs
Microsoft: Happy 2025. Here’s 161 Security Updates↗2025-01-14
▶
Tenable
Microsoft’s January 2025 Patch Tuesday Addresses 157 CVEs (CVE-2025-21333, CVE-2025-21334, CVE-2025-21335)↗2025-01-14
▶
CVE-2025-21334 — Use After Free in Microsoft | cvebase