CVE Alert: CVE-2025-54099 – Microsoft – Windows 10 Version 1809

Risk verdict

High risk of local privilege escalation on Windows endpoints; exploitation is not currently observed in the wild, but patching should be treated as urgent.

Why this matters

Authenticated attackers can elevate to SYSTEM via a stack-based overflow in the kernel driver, enabling full host compromise, persistence, and potential lateral movement. With a broad set of affected Windows versions, enterprises face widespread exposure across desktops and servers.

Most likely attack path

Requires local access (AV:L) and no user interaction (UI:N) but high complexity (AC:H). An attacker with foothold could trigger the kernel overflow in the WinSock ancillary driver, gaining SYSTEM privileges and then leveraging credentials to move laterally within the network.

Who is most exposed

Organisation-wide risk for those running Windows 10/11 and Windows Server deployments on affected builds, especially where patching lags or older servers remain unpatched.

Detection ideas

• Kernel crash dumps or blue-screen events referencing afd.sys or WinSock components
• Unauthorised creation or spawning of SYSTEM-level processes from non-privileged accounts
• Unscheduled driver load/unload events for the WinSock ancillary driver

Mitigation and prioritisation

• Patch all affected Windows builds to the latest cumulative updates; verify inventory and patch status
• Enforce least-privilege, monitor for privilege-escalation activity, and restrict local admin use
• Enable EDR with kernel-diagnostic logging; promptly investigate related crash dumps
• Change-management: schedule testing in a staging environment, then deploy in waves to minimise disruption