Force crash an application

The best way is to call RaiseException API from windows.h

RaiseException(0x0000DEAD,0,0,0);

Or you can do a runtime linking to KeBugCheckEx() from ntoskrnl.exe and call it in your code.

Example:

#include <windows.h>
#include <iostream>
using namespace std;

int main()
{
    HINSTANCE h = LoadLibrary("ntoskrnl.exe");
    cout<<h<<endl;
    void* a;
    a = (void*) GetProcAddress(h,"KeBugCheckEx");
    int(*KeBugCheckEx)(ULONG,ULONG_PTR,ULONG_PTR,ULONG_PTR,ULONG_PTR);
    KeBugCheckEx = (int(*)(ULONG,ULONG_PTR,ULONG_PTR,ULONG_PTR,ULONG_PTR))a;

    cout << a;
    KeBugCheckEx(0,0,0,0,0); //crash in module ntoskrnl.exe means that call success!
}

Assuming Windows, see Application Verifier.

It can do fault injection (Low Resource Simulation) that makes various API calls fail, at configurable rates. E.g. Heap allocations, Virtual Alloc, WaitForXxx, Registry APIs, Filesystem APIs, and more.

You can even specify a grace period (in milliseconds) when no faults will be injected during startup.

On Windows you can attach WinDbg to a process, corrupt some register or memory and detach. For instance you can set instruction pointer to 0 for some active application thread.

windbg -pn notepad.exe

Right after attach, current thread is set to debug thread, so you need to change to app thread to make it crash with RIP register update

0:008> ~0s 
0:000> rip=0
0:000> qd