93 lines
2.8 KiB
Ruby
93 lines
2.8 KiB
Ruby
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##
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# This module requires Metasploit: http//metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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require 'msf/core'
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class Metasploit3 < Msf::Auxiliary
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include Msf::Auxiliary::Report
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include Msf::Exploit::Remote::Udp
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include Msf::Auxiliary::UDPScanner
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include Msf::Auxiliary::NTP
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def initialize
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super(
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'Name' => 'NTP Mode 6 REQ_NONCE DRDoS Scanner',
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'Description' => %q{
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This module identifies NTP servers which permit mode 6 REQ_NONCE requests that
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can be used to conduct DRDoS attacks. In some configurations, NTP servers will
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respond to REQ_NONCE requests with a response larger than the request,
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allowing remote attackers to cause a denial of services (traffic
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amplification) via spoofed requests.
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},
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'References' =>
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[
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],
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'Author' => 'Jon Hart <jon_hart[at]rapid7.com>',
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'License' => MSF_LICENSE
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)
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end
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# Called for each IP in the batch
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def scan_host(ip)
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scanner_send(@probe, ip, datastore['RPORT'])
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end
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# Called for each response packet
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def scanner_process(data, shost, sport)
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this_peer = "#{shost}:#{sport}"
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# sanity check that the reply is not overly large/small
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if data.length < 12
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print_error("#{this_peer} -- suspiciously small (#{data.length} bytes) NTP req_nonce response")
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return
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elsif data.length > 500
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print_error("#{this_peer} -- suspiciously large (#{data.length} bytes) NTP req_nonce response")
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return
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end
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# try to parse this response, alerting and aborting if it is invalid
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response = Rex::Proto::NTP::NTPControl.new(data)
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if [ @probe.version, @probe.operation ] == [ response.version, response.operation ]
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@results[shost] ||= []
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@results[shost] << response
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else
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print_error("#{this_peer} -- unexpected NTP req_nonce response: #{response.inspect}")
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end
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end
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# Called before the scan block
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def scanner_prescan(batch)
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@results = {}
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@probe = Rex::Proto::NTP::NTPControl.new
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@probe.version = 2
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@probe.operation = 12
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vprint_status("Sending probes to #{batch[0]}->#{batch[-1]} (#{batch.length} hosts)")
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end
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# Called after the scan block
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def scanner_postscan(batch)
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@results.keys.each do |k|
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packets = @results[k]
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report_service(
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:host => k,
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:proto => 'udp',
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:port => rport,
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:name => 'ntp'
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)
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report_note(
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:host => k,
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:proto => 'udp',
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:port => rport,
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:type => 'ntp.req_nonce',
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:data => {:req_nonce => @results[k]}
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)
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total_size = packets.map(&:size).reduce(:+)
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if packets.size > 1 || total_size > @probe.size
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print_good("#{k}:#{rport} NTP req_nonce request permitted with amplified response (#{packets.size} packets, #{total_size} bytes)")
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end
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end
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end
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end
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