Module: Msf::Sessions::MettleConfig

Includes:
Payload::TransportConfig
Defined in:
lib/msf/base/sessions/mettle_config.rb

Constant Summary

Constants included from Rex::Payloads::Meterpreter::UriChecksum

Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_CONN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_CONN_MAX_LEN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITJ, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITP, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITPH, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INITW, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_INIT_CONN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_MIN_LEN, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_MODES, Rex::Payloads::Meterpreter::UriChecksum::URI_CHECKSUM_UUID_MIN_LEN

Instance Method Summary collapse

Methods included from Payload::TransportConfig

#transport_config_bind_named_pipe, #transport_config_bind_tcp, #transport_config_reverse_http, #transport_config_reverse_https, #transport_config_reverse_ipv6_tcp, #transport_config_reverse_named_pipe, #transport_config_reverse_tcp, #transport_config_reverse_udp, #transport_uri_components

Methods included from Payload::UUID::Options

#generate_payload_uuid, #generate_uri_uuid_mode, #record_payload_uuid, #record_payload_uuid_url

Methods included from Rex::Payloads::Meterpreter::UriChecksum

#generate_uri_checksum, #generate_uri_uuid, #process_cookie_resource, #process_query_string_resource, #process_uri_resource, #process_uuid_string, #uri_checksum_lookup

Instance Method Details

#encode_stage? ⇒ Boolean

Stage encoding is not safe for Mettle (doesn’t apply to stageless)

Returns:

  • (Boolean) 


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# File 'lib/msf/base/sessions/mettle_config.rb', line 167

def encode_stage?
  if datastore['EnableStageEncoding'] && !@warned
    print_warning("Stage encoding is not supported for #{refname}")
    @warned = true
  end

  false
end

#generate_config(opts = {}) ⇒ Object 



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# File 'lib/msf/base/sessions/mettle_config.rb', line 88

def generate_config(opts = {})
  ds = opts[:datastore] || datastore

  opts[:background] = ds['MeterpreterTryToFork'] ? 1 : 0

  if ds['PayloadProcessCommandLine'] != ''
    opts[:name] ||= ds['PayloadProcessCommandLine']
  end

  opts[:uuid] ||= generate_payload_uuid

  unless opts[:transport_config]
    if opts[:stageless] == true
      case opts[:scheme]
      when 'http'
        opts[:transport_config] = [transport_config_reverse_http(opts)]
      when 'https'
        opts[:transport_config] = [transport_config_reverse_https(opts)]
      when 'tcp'
        opts[:transport_config] = [transport_config_reverse_tcp(opts)]
      else
        raise ArgumentError, "Unknown scheme: #{opts[:scheme]}"
      end
    else
      # Staged payloads inherit the stager's socket (fd transport);
      # the stage must not synthesise its own C2 transport. Use an
      # explicit empty array ([] is truthy, so the build is skipped).
      opts[:transport_config] = []
    end
  end

  # Generate the TLV config block
  config_opts = {
    ascii_str:         true,
    null_session_guid: opts[:stageless] == true,
    expiration:        (ds[:expiration] || ds['SessionExpirationTimeout']).to_i,
    uuid:              opts[:uuid],
    transports:        opts[:transport_config],
    extensions:        opts[:extensions] || [],
    ext_format:        'bin',
    mettle_platform:   opts[:mettle_platform],
    stageless:         opts[:stageless] == true,
  }.merge(meterpreter_logging_config(opts))

  config = Rex::Payloads::Meterpreter::Config.new(config_opts)
  opts[:config_block] = config.to_b

  # Mettle reserves a fixed 8 KB slot in the binary for the config
  # block. Catch the overflow here with a useful message instead of
  # letting the gem's `to_binary` raise a generic "config block too
  # large" -- baked-in EXTENSIONS= is the usual culprit.
  if opts[:config_block].length > MetasploitPayloads::Mettle::CONFIG_BLOCK_MAX
    raise ArgumentError, "Mettle config block (#{opts[:config_block].length} bytes) exceeds the #{MetasploitPayloads::Mettle::CONFIG_BLOCK_MAX}-byte embedded slot. " \
      "Drop EXTENSIONS= and `load <ext>` once the session is up."
  end

  # Keep the legacy CLI config for backward compatibility during
  # transition. Skipped for staged payloads, which have no transport.
  transport = opts[:transport_config].first
  if transport
    case opts[:scheme]
    when 'http', 'https'
      opts[:uri] = generate_http_uri(transport)
    when 'tcp'
      opts[:uri] = generate_tcp_uri(transport)
    end
  end

  opts[:uuid] = Base64.encode64(opts[:uuid].to_raw).strip
  guid = "\x00" * 16
  unless opts[:stageless] == true
    guid = [SecureRandom.uuid.gsub('-', '')].pack('H*')
  end
  opts[:session_guid] = Base64.encode64(guid).strip

  opts.slice(:uuid, :session_guid, :uri, :debug, :log_file, :name, :background, :config_block)
end

#generate_http_uri(opts) ⇒ Object 



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# File 'lib/msf/base/sessions/mettle_config.rb', line 55

def generate_http_uri(opts)
  if Rex::Socket.is_ipv6?(opts[:lhost])
    target_uri = "#{opts[:scheme]}://[#{opts[:lhost]}]"
  else
    target_uri = "#{opts[:scheme]}://#{opts[:lhost]}"
  end

  target_uri << ':'
  target_uri << opts[:lport].to_s
  target_uri << luri
  target_uri << generate_uri(opts)
  target_uri << '|'
  target_uri << generate_uri_option(opts, :ua)
  target_uri << generate_uri_option(opts, :host)
  target_uri << generate_uri_option(opts, :referer)
  if opts[:cookie]
    opts[:header] = "Cookie: #{opts[:cookie]}"
    target_uri << generate_uri_option(opts, :header)
  end
  target_uri.strip
end

#generate_tcp_uri(opts) ⇒ Object 



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# File 'lib/msf/base/sessions/mettle_config.rb', line 77

def generate_tcp_uri(opts)
  if Rex::Socket.is_ipv6?(opts[:lhost])
    target_uri = "#{opts[:scheme]}://[#{opts[:lhost]}]"
  else
    target_uri = "#{opts[:scheme]}://#{opts[:lhost]}"
  end
  target_uri << ':'
  target_uri << opts[:lport].to_s
  target_uri
end

#generate_uri(opts = {}) ⇒ Object 



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# File 'lib/msf/base/sessions/mettle_config.rb', line 35

def generate_uri(opts = {})
  ds = opts[:datastore] || datastore
  uri_req_len = ds['StagerURILength'].to_i

  # Choose a random URI length between 30 and 128 bytes
  if uri_req_len == 0
    uri_req_len = 30 + luri.length + rand(127 - (30 + luri.length))
  end

  if uri_req_len < 5
    raise ArgumentError, 'Minimum StagerURILength is 5'
  end

  generate_uri_uuid_mode(:init_connect, uri_req_len, uuid: opts[:uuid])
end

#generate_uri_option(opts, opt) ⇒ Object 



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# File 'lib/msf/base/sessions/mettle_config.rb', line 51

def generate_uri_option(opts, opt)
  opts[opt] ? "--#{opt} '#{opts[opt].gsub('\'', "\\'")}' " : ''
end

#initialize(info = {}) ⇒ Object 



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# File 'lib/msf/base/sessions/mettle_config.rb', line 11

def initialize(info = {})
  super

  register_advanced_options(
    [
      OptBool.new(
        'MeterpreterTryToFork',
        'Fork a new process if the functionality is available',
        default: false
      ),
    ]
  )
  unless staged?
    register_advanced_options(
      [
        OptEnum.new(
          'PayloadLinuxMinKernel',
          [true, 'Linux minimum kernel version for compatibility', '2.6', ['2.6', '3.17']]
        )
      ]
    )
  end
end