UDP Amplification Scanner

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

class MetasploitModule < Msf::Auxiliary
include Msf::Auxiliary::DRDoS
include Msf::Auxiliary::Report
include Msf::Auxiliary::UDPScanner

def initialize
super(
‘Name’ => ‘UDP Amplification Scanner’,
‘Description’ => ‘Detect UDP endpoints with UDP amplification vulnerabilities’,
‘Author’ => ‘Jon Hart <jon_hart[at]rapid7.com>’,
‘License’ => MSF_LICENSE,
‘References’ =>
[
[‘CVE’, ‘2013-5211’], # see also scanner/ntp/ntp_monlist.rb
[‘URL’, ‘https://www.cisa.gov/uscert/ncas/alerts/TA14-017A’]])

register_options(
[
OptString.new(‘PORTS’, [true, ‘Ports to probe’]),
OptString.new(‘PROBE’, [false, ‘UDP payload/probe to send. Unset for an empty UDP datagram, or the `file://` resource to get content from a local file’])
])

# RPORT is unused in this scanner module because it supports multiple ports
deregister_options(‘RPORT’)
end

def setup
super

unless (@ports = Rex::Socket.portspec_crack(datastore[‘PORTS’]))
fail_with(Failure::BadConfig, “Unable to extract list of ports from #{datastore[‘PORTS’]}”)
end

@probe = datastore[‘PROBE’] ? datastore[‘PROBE’] : ”
end

def scanner_prescan(batch)
print_status(“Sending #{@probe.length}-byte probes to #{@ports.length} port(s) on #{batch[0]}->#{batch[-1]} (#{batch.length} hosts)”)
@results ||= {}
end

def scan_host(ip)
@ports.each do |port|
scanner_send(@probe, ip, port)
end
end

# Called for each response packet, overriding UDPScanner’s so that we can
# store all responses on a per-host, per-port basis
def scanner_process(data, shost, sport)
@results[shost] ||= {}
@results[shost][sport] ||= []@results[shost][sport] << data
end

def scanner_postscan(batch)
batch.each do |shost|
next unless @results.key?(shost)
@results[shost].each_pair do |sport, responses|
report_service(host: shost, port: sport, proto: ‘udp’, info: responses.inspect, state: ‘open’)
vulnerable, proof = prove_amplification(@probe => responses)
next unless vulnerable
print_good(“#{shost}:#{sport} – susceptible to UDP amplification: #{proof}”)
report_vuln(
host: shost,
port: sport,
proto: ‘udp’,
name: ‘UDP amplification’,
refs: references
)
end
end
end
end