Causing a deliberate DEP error

Question

In short what I want to do is be able to cause a Data Execution Prevention (DEP) error at will.

This is specifically on XP SP3 machines. I'd like it so that when I run a script or small program it brings up the XP DEP error box.

Would I be right in thinking the simplest way to do that is with some sort of script or program? I know DEP is used to prevent buffer overflow attacks but i'd rather not risk any malicious code being used.

Can anybody suggest anything to get me on the right lines?

Answer 1

The simplest way is to allocate memory without the executable attribute and jump to the address allocated. This can be done with the following code.

void Code(){
    return;
}

void GenerateDepError(){

    // Allocate data area
    PVOID pMem = VirtualAlloc( NULL, 0x100, 
                               MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE );

    // Copy a function into data area
    for( DWORD i = 0; i < 0x100; i++ ){
        ((char*)pMem)[i] = ((char*)Code)[i]; 
    }

    // Consider the memory area as a function. 
    void (*dep_trigger)() = (void (*)())pMem; 

    // Invoke the function. This should cause DEP error if DEP is ON.
    dep_trigger(); 

    // If it returns without error this message will be displayed.
    printf("No error on dep_trigger()\n"); 
}

int main( int argc, char** argv ){
    GenerateDepError();
    return 0;
}