PassMark PerformanceTest before 11.1 build 1012, BurnInTest before 11.1 build 1000, and OSForensics before 11.1 build 1016 contain a hard-coded credentials vulnerability in DirectIo64.sys that allows local attackers to perform arbitrary physical memory writes by extracting an 8-byte key embedded as a hardcoded literal in the distributed binary and computing valid MD5 authentication tags for arbitrary IOCTL write requests. Attackers can additionally bypass a secondary validation gate by using the driver's own bit-clear IOCTL to clear a single bit in the gating instruction's displacement byte, causing all subsequent write requests to skip MAC verification, size checks, and Vendor ID checks entirely.