CVE-2025-21334
Published: January 14, 2025
Official Description
Microsoft Windows Hyper-V NT Kernel Integration VSP contains a use-after-free vulnerability that allows a local attacker to gain SYSTEM privileges.
CISA KEV Advisory
Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability
Microsoft Windows Hyper-V NT Kernel Integration VSP contains a use-after-free vulnerability that allows a local attacker to gain SYSTEM privileges.
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Risk Analysis
This use-after-free vulnerability in Microsoft Windows Hyper-V NT Kernel Integration VSP allows a local attacker to gain SYSTEM privileges. Its presence in CISA's KEV catalog and an EPSS score of 0.07561 highlight a confirmed and elevated risk of exploitation.
This vulnerability is actively exploited in the wild, indicating its use by attackers. Exploitation requires local access to the affected system.
Apply the latest security updates from Microsoft to address this Hyper-V vulnerability. Restrict local access to systems running Hyper-V to reduce the attack surface.
Technical Analysis
CVE-2025-21334 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2025-21334 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2025-21334 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1