A critical SQL Injection vulnerability has been discovered in the Canteen Management System version 1., affecting one of its core components. Specifically, the vulnerability lies within the userid parameter at /php_action/fetchSelectedUser.php, allowing an attacker to execute arbitrary SQL code on the application's database. This vulnerability has been assigned the identifier CVE-2022-43233.

In this long-read post, we will discuss the details of this vulnerability, analyze a code snippet that exemplifies the issue, and provide links to original references and exploit information for further investigation and mitigation.

Vulnerability Details

The Canteen Management System v1. is an open-source web application that assists organizations in managing their canteens effectively. Unfortunately, the developers did not validate or sanitize user input properly in the userid parameter of /php_action/fetchSelectedUser.php, which leads to a SQL Injection vulnerability that can be exploited by a malicious actor.

Exploiting the vulnerability allows the attacker to perform various actions, such as extracting sensitive data from the database, modifying or deleting records, and potentially elevating privileges to take control of the system. In the hands of a skilled attacker, this flaw can have severe consequences for organizations utilizing the vulnerable software.

Code Snippet Analysis

Below is an example of a vulnerable code snippet from the Canteen Management System v1. at /php_action/fetchSelectedUser.php:

// ...
$userId = $_GET['userid'];
$sql = "SELECT * FROM users WHERE user_id = $userId";
$result = $connect->query($sql);
// ...

In this example, user input provided through the "userid" GET parameter is directly included in the SQL query without any validation or sanitization, making it prone to SQL Injection attacks. An attacker could exploit this vulnerability by sending crafted input that includes malicious SQL code.

For example, the following input could be used to bypass authentication and reveal all records from the "users" table:

userid=1 OR 1=1

If the attacker supplies this input, the resulting query becomes

SELECT * FROM users WHERE user_id = 1 OR 1=1

This query will succeed and return all records since the condition (1=1) is always true.

Original References

1. The National Institute of Standards and Technology (NIST) has published an informational entry for the vulnerability in its National Vulnerability Database (NVD), which can be accessed here: https://nvd.nist.gov/vuln/detail/CVE-2022-43233
2. The original source code repository for the vulnerable application can be found on GitHub here: https://github.com/lukaszakwocz/canteen_management_system

Exploit Details

At present, there is no public exploit code available for this specific vulnerability. However, it's essential to keep in mind that numerous SQL Injection exploitation techniques and tools can be adapted to target this particular flaw. Some known tools for exploiting SQL Injection vulnerabilities include SQLMap, Havij, and jSQL.


To mitigate this vulnerability, the developers should implement proper input validation and sanitization for all parameters, particularly those used in SQL queries. Several PHP functions, such as "mysqli_real_escape_string" or "intval," can help prevent SQL injection.

Until a patch is released, organizations using the vulnerable Canteen Management System v1. should carefully review their input validation processes and consider implementing Web Application Firewalls (WAFs) or Intrusion Detection Systems (IDS) to monitor and block SQL Injection attacks.


The discovery of CVE-2022-43233 serves as a reminder of the importance of proper input validation and sanitization in web applications. Organizations using the Canteen Management System v1. should be aware of this vulnerability and take necessary steps to secure their systems until an official patch is available. In addition, it's crucial to stay informed about similar vulnerabilities and learn from the mistakes of others to improve overall security.


Published on: 10/28/2022 18:15:00 UTC
Last modified on: 10/28/2022 19:48:00 UTC