Cyber Posture

CVE-2025-21334

HighCISA KEVActive Exploitation

Published: 14 January 2025

Published
14 January 2025
Modified
27 October 2025
KEV Added
14 January 2025
Patch
CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0580 90.6th percentile
Risk Priority 39 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21334 is a high-severity Use After Free (CWE-416) vulnerability in Microsoft Windows 11 22H2. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 9.4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly remediates the Use After Free flaw in Windows Hyper-V by requiring timely application of vendor patches.

prevent

Implements memory safeguards such as DEP and ASLR to protect against exploitation of the Use After Free vulnerability in the Hyper-V kernel component.

prevent

Enforces least privilege to restrict low-privilege local attackers from gaining the initial access needed to exploit the elevation vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Local use-after-free vulnerability in Hyper-V kernel component enabling direct privilege escalation from low-privileged local access.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

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

Deeper analysisAI

CVE-2025-21334 is an elevation of privilege vulnerability in the Windows Hyper-V NT Kernel Integration VSP component, stemming from a CWE-416 (Use After Free) flaw. It affects Windows Hyper-V systems and was published on 2025-01-14 with a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high impact potential from local access.

A local attacker with low privileges can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation allows the attacker to elevate privileges, potentially gaining high confidentiality, integrity, and availability impacts on the affected system.

Microsoft's update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21334 provides details on patches and mitigation steps. The vulnerability is also listed in CISA's Known Exploited Vulnerabilities catalog at https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21334, indicating real-world exploitation.

Details

CWE(s)
KEV Date Added
14 January 2025

Affected Products

microsoft
windows 10 21h2
≤ 10.0.19044.5371
microsoft
windows 10 22h2
≤ 10.0.19045.5371
microsoft
windows 11 22h2
≤ 10.0.22621.4751 · ≤ 10.0.22621.4751
microsoft
windows 11 23h2
≤ 10.0.22631.4751 · ≤ 10.0.22631.4751
microsoft
windows 11 24h2
≤ 10.0.26100.2894 · ≤ 10.0.26100.2894
microsoft
windows server 2022 23h2
≤ 10.0.25398.1369
microsoft
windows server 2025
≤ 10.0.26100.2894

CVEs Like This One

CVE-2025-21335Same product: Microsoft Windows 10 21H2both on KEV
CVE-2025-62221Same product: Microsoft Windows 10 21H2both on KEV
CVE-2025-21333Same product: Microsoft Windows 10 21H2both on KEV
CVE-2025-21367Same product: Microsoft Windows 10 21H2
CVE-2026-20871Same product: Microsoft Windows 10 21H2
CVE-2026-32155Same product: Microsoft Windows 10 21H2
CVE-2026-26132Same product: Microsoft Windows 10 21H2
CVE-2026-20923Same product: Microsoft Windows 10 21H2
CVE-2025-62215Same product: Microsoft Windows 10 21H2both on KEV
CVE-2026-20865Same product: Microsoft Windows 10 21H2

References