February 11, 2025 · Applied Cybernetics Group
CVE-2025-21418 — Microsoft Windows
Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
- Added to KEV
2025-02-11- Federal due date
2025-03-04- Vendor
- Microsoft
- Product
- Windows
- EPSS
- 93.3th percentile (score 0.103, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2025-21418
CISA short description
Microsoft Windows Ancillary Function Driver for WinSock contains a heap-based buffer overflow vulnerability that allows for privilege escalation, enabling a local attacker to gain SYSTEM privileges.
Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.