Chargen Probe Utility

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Auxiliary  
include Msf::Auxiliary::Scanner  
include Msf::Exploit::Capture  
include Msf::Auxiliary::Report  
include Msf::Exploit::Remote::Udp  
include Msf::Auxiliary::DRDoS  
include Msf::Auxiliary::UDPScanner  
  
def initialize  
super(  
'Name' => 'Chargen Probe Utility',  
'Description' => %q{  
Chargen is a debugging and measurement tool and a character  
generator service. A character generator service simply sends  
data without regard to the input.  
Chargen is susceptible to spoofing the source of transmissions  
as well as use in a reflection attack vector. The misuse of the  
testing features of the Chargen service may allow attackers to  
craft malicious network payloads and reflect them by spoofing  
the transmission source to effectively direct it to a target.  
This can result in traffic loops and service degradation with  
large amounts of network traffic.  
},  
'Author' => 'Matteo Cantoni <goony[at]nothink.org>',  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'CVE', '1999-0103' ], # Note, does not actually trigger a flood.  
[ 'URL', 'http://tools.ietf.org/html/rfc864' ]  
],  
'DisclosureDate' => 'Feb 08 1996')  
  
register_options([  
Opt::RPORT(19)  
])  
end  
  
def run_host(rhost)  
data = Rex::Text.rand_text_alpha_lower(1)  
if spoofed?  
scanner_spoof_send(data, rhost, datastore['RPORT'], datastore['SRCIP'], datastore['NUM_REQUESTS'])  
else  
begin  
connect_udp  
udp_sock.write(data)  
r = udp_sock.recvfrom(65535, 0.1)  
  
if r and r[1]  
vprint_status("#{rhost}:#{rport} - Response: #{r[0].to_s}")  
res = r[0].to_s.strip  
if (res.match(/ABCDEFGHIJKLMNOPQRSTUVWXYZ/i) || res.match(/0123456789/))  
print_good("#{rhost}:#{rport} answers with #{res.length} bytes (headers + UDP payload)")  
report_service(:host => rhost, :port => rport, :proto => "udp", :name => "chargen", :info => res.length)  
end  
end  
rescue ::Rex::HostUnreachable, ::Rex::ConnectionTimeout, ::Rex::ConnectionRefused  
nil  
ensure  
disconnect_udp if self.udp_sock  
end  
end  
end  
end  
`