Hw64.sys in Marvin Test HW.exe before 5.0.5.0 allows unprivileged user-mode processes to arbitrarily map physical memory via IOCTL 0x9c406490 (for IoAllocateMdl, MmBuildMdlForNonPagedPool, and MmMapLockedPages), leading to NT AUTHORITY\SYSTEM privilege escalation.
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