In Sophos Tester Tool 3.2.0.7 Beta, the driver accepts a special DeviceIoControl code that doesn't check its argument. This argument is a memory address: if a caller passes a NULL pointer or a random invalid address, the driver will cause a Blue Screen of Death. If a program or malware does this at boot time, it can cause a persistent denial of service on the machine.

In Sophos Tester Tool 3.2.0.7 Beta, the driver loads (in the context of the application used to test an exploit or ransomware) the DLL using a payload that runs from NTDLL.DLL (so, it's run in userland), but the driver doesn't perform any validation of this DLL (not its signature, not its hash, etc.). A person can change this DLL in a local way, or with a remote connection, to a malicious DLL with the same name -- and when the product is used, this malicious DLL will be loaded, aka a DLL Hijacking attack.