CVE-2023-40946: Critical SQL Injection Vulnerability Discovered in Schoolmate 1.3

We would like to address a critical security vulnerability that was recently discovered in Schoolmate 1.3. The vulnerability has been assigned the Common Vulnerabilities and Exposures (CVE) ID of CVE-2023-40946 and is classified as an SQL Injection vulnerability. Schoolmate is a widely used online school management system, and this vulnerability may potentially affect numerous schools and institutions.

Vulnerability Details

The vulnerability exists in Schoolmate's ValidateLogin.php file, where user-supplied input through the $username variable from session data is not being properly sanitized before being used in an SQL query. This allows an attacker to execute malicious SQL code, which may give them unauthorized access and control over the database containing sensitive information.

Here's a code snippet from the affected file, where the vulnerability exists

// ValidateLogin.php
$username = $_SESSION['uname_log'];
$validateuser = mysql_query("SELECT COUNT(*) AS numrows FROM hb_members WHERE username='$username'") or die(mysql_errno().' - '.mysql_error());

Exploitation

An attacker can exploit this vulnerability by sending a specially crafted value in the $username variable, such as a string containing SQL code. This may result in the execution of the injected code within the context of the targeted database system, potentially allowing the attacker to read, modify, or delete sensitive data, as well as execute administrative tasks such as creating a new user with administrative privileges.

' OR '1'='1

The injected SQL code will modify the original SQL query, making it possible to bypass authentication or retrieve additional information from the database without proper authorization. This represents a serious security risk, as an attacker can gain unauthorized access to Schoolmate's underlying database, potentially exposing sensitive user data.

Mitigation and Recommendations

The proper way to mitigate this vulnerability is to sanitize user-supplied input before using it in an SQL query. This can be achieved by using prepared statements or various PHP methods such as mysql_real_escape_string() or mysqli_real_escape_string() to escape potentially dangerous characters in the user input. For example, the affected code can be altered as follows:

// ValidateLogin.php (patched)
$username = mysqli_real_escape_string($connection, $_SESSION['uname_log']);
$validateuser = mysqli_query($connection, "SELECT COUNT(*) AS numrows FROM hb_members WHERE username='$username'") or die(mysqli_errno($connection).' - '.mysqli_error($connection));

We highly recommend Schoolmate users and developers to apply this patch or similar measures to prevent this vulnerability's exploitation. Implementing input validation and parameterized SQL queries can provide a more secure environment for user data. Furthermore, it is advised to keep software up-to-date by regularly applying security patches and updates.

Here are some helpful links to learn more about SQL injection vulnerabilities and their prevention

- OWASP SQL Injection Guide
- OWASP SQL Injection Prevention Cheat Sheet

In conclusion, CVE-2023-40946 is a critical SQL injection vulnerability in Schoolmate 1.3 that may have severe implications for affected schools and institutions. Proper input sanitization, along with the use of prepared statements and parameterized queries, can help to prevent the exploitation of this vulnerability and secure Schoolmate users' data.

Timeline

Published on: 09/11/2023 20:15:10 UTC
Last modified on: 09/13/2023 03:49:05 UTC