Cloud | Sync Driver Escalation

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Executive Snapshot Your users believe cloud file sync is a productivity feature. Attackers see the Windows Cloud Files Mini Filter Driver as a kernel-level privilege escalation pathway present on every Windows 10 and 11 endpoint, whether OneDrive is installed or not.

Signal This zero-day exploits a file system driver embedded in Windows itself, meaning the attack surface exists on every modern Windows endpoint regardless of whether cloud sync applications are actively used.

Strategic Implication You cannot uninstall your way out of this exposure. The vulnerable component ships with the operating system.

Action Deploy the December 2025 Windows security update addressing CVE-2025-62221 to all endpoints today. Hunt for anomalous privilege escalation activity and suspicious interactions with cldflt.sys across your fleet now. Validate that automated patch management coverage includes Windows 10 endpoints approaching end-of-life and ensure Extended Security Update agreements are in place this week.