LDAP Injection in Laravel: Prevention & Secure Coding

Introduction

LDAP (Lightweight Directory Access Protocol) is widely used for authentication and user data retrieval. However, if not properly handled, LDAP queries can be manipulated, leading to LDAP Injection attacks. In Laravel applications, poor input validation and direct query concatenation make them vulnerable to such exploits.

In this guide, we will explore LDAP Injection in Laravel, its risks, and secure coding practices with multiple coding examples.

---

What is LDAP Injection?

LDAP Injection occurs when an attacker manipulates LDAP queries by injecting malicious input, often bypassing authentication and gaining unauthorized access to sensitive data.

Example of a Vulnerable LDAP Query

Consider a Laravel application using LDAP authentication:

$username = $_GET['username'];
$password = $_GET['password'];

$ldapconn = ldap_connect("ldap://example.com") or die("Could not connect");

$filter = "(uid=$username)";
$search = ldap_search($ldapconn, "dc=example,dc=com", $filter);
$entries = ldap_get_entries($ldapconn, $search);

if ($entries["count"] > 0) {
    echo "User authenticated";
} else {
    echo "Invalid credentials";
}

Why is this Vulnerable?

The input $username is directly used in the LDAP filter, making it susceptible to injection. An attacker could bypass authentication using:

username=*)(&) (password=anything

This results in a manipulated query:

(uid=*)(password=anything)

This always evaluates to true, granting unauthorized access.

---

How to Prevent LDAP Injection in Laravel?

1. Use Parameterized Queries

Using ldap_escape() prevents special characters from manipulating LDAP queries.

$username = ldap_escape($_GET['username'], "", LDAP_ESCAPE_FILTER);
$password = ldap_escape($_GET['password'], "", LDAP_ESCAPE_FILTER);

$filter = "(uid=$username)";
$search = ldap_search($ldapconn, "dc=example,dc=com", $filter);

2. Validate User Input

Sanitize and validate inputs before using them in LDAP queries.

$username = filter_var($_GET['username'], FILTER_SANITIZE_STRING);
$password = filter_var($_GET['password'], FILTER_SANITIZE_STRING);

3. Implement Role-Based Access Control (RBAC)

Limit LDAP permissions based on user roles.

if ($userRole !== 'admin') {
    die("Access denied.");
}

4. Use Secure Bind Authentication

Instead of filtering directly, authenticate securely.

$ldapbind = ldap_bind($ldapconn, "uid=$username,dc=example,dc=com", $password);

5. Restrict Special Characters

Prevent attackers from injecting wildcard characters like * or |.

if (preg_match('/[\*\(\)\|\&]/', $username)) {
    die("Invalid input detected.");
}

---

Screenshot 1: Our Free Website Security Checker

To ensure your Laravel application is secure from LDAP Injection, use our free website security scanner.

Screenshot of the free tools webpage where you can access security assessment tools.

---

Real-World Example of LDAP Injection Exploitation

An attacker can use tools like LDAP Injection Fuzzer to manipulate queries.

Exploitable Payload Example

username=*)(|(objectClass=*))(

If the application is vulnerable, this could expose all user accounts stored in LDAP.

---

Screenshot 2: Website Vulnerability Assessment Report

We conducted a website vulnerability scan using our free tool to check website vulnerability. Here’s an example of a security report detecting LDAP Injection vulnerabilities.

An Example of a vulnerability assessment report generated with our free tool, providing insights into possible vulnerabilities.

---

Best Practices to Secure LDAP in Laravel

✅ Always sanitize and escape user input
✅ Use parameterized queries
✅ Apply role-based authentication
✅ Limit access permissions
✅ Monitor and audit LDAP queries

---

Conclusion

LDAP Injection is a critical security flaw that can expose sensitive user data and grant unauthorized access. By following secure coding practices in Laravel, you can prevent attacks and keep your application safe.

🔗 Read more about web security vulnerabilities on our blog at https://www.pentesttesting.com/blog/.

💡 Want to check your website’s security? Use our free security scanner now!