Missing access rights when running -Ex functions on current process

[lnx00]

I am currently working with a VMProtect'ed game on windows where the pseudo handle returned from "GetCurrentProcess()" seems to have restricted access rights. For example, calls to VirtualProtectEx/VirtualProtect on this handle to set RWX permissions will fail. It is possible to bypass this protection by opening a new handle with the required access flags (PROCESS_VM_OPERATION) and then pass is to the -Ex functions.

However, using the LM_WriteMemoryEx- and LM_HookCodeEx-functions doesn't work because libmem's open_process implementation for windows simply returns the restricted handle from "GetCurrentProcess()", if it determines that the call comes from the current process:

libmem/internal/winutils/winutils.c

Lines 90 to 96 in a6136d6

	open_process(DWORD pid, DWORD access)
	{
	if (pid == GetCurrentProcessId())
	return GetCurrentProcess();
	return OpenProcess(access, FALSE, pid);
	}

Solution

Since the open_process implementation seems to only be called inside libmem's -Ex functions, it should probably be fine to remove the if statement. If someone calls an -Ex function explicitly, they probably have an intention in doing so.