Windows Downdate tool lets you 'unpatch' Windows systems

SafeBreach researcher Alon Leviev released Windows Downdate, an open-source tool and Windows executable that forces up-to-date Windows 10/11 and Server components to revert to older, vulnerable versions—reintroducing past flaws and enabling exploitation (including examples targeting CVE-2024-21302 and CVE-2024-38202). The tool can downgrade hypervisor, kernel, drivers, and bypass VBS UEFI locks, is described as undetectable by EDR while Windows Update reports systems as up-to-date; Microsoft has patched CVE-2024-21302 but not CVE-2024-38202, and mitigation guidance is provided.