CVE-2025-21418 Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow
An attacker can exploit a heap-based buffer overflow in the Windows Ancillary Function Driver to gain elevated privileges.
- Exploited in the wild
- Since 11 Feb 2025
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-21418?
CVE-2025-21418 is a high-severity memory corruption vulnerability in Microsoft Windows 10 1607, published on 11 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Weakness: CWE-122
Which versions are affected by CVE-2025-21418?
It affects 14 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 22h2, Microsoft Windows 11 23h2 and 8 more.
How do I fix CVE-2025-21418?
No fix has been published for CVE-2025-21418 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 4 Mar 2025.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-21418 being exploited?
Yes. Attackers have exploited CVE-2025-21418 in the wild since at least 11 Feb 2025.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-5fhq-7w32-vhww.