LDAP Injection Prevention

Introduction

LDAP (Lightweight Directory Access Protocol) injection is a type of attack that exploits web applications that construct LDAP queries based on user input. This lesson covers the concepts, how it works, and how to prevent LDAP Injection vulnerabilities.

What is LDAP Injection?

LDAP injection occurs when an attacker manipulates LDAP queries by injecting malicious content into user input fields. This can lead to unauthorized access, data retrieval, or alteration of directory information.

How LDAP Injection Works

LDAP injection typically occurs when user input is concatenated into an LDAP query without proper validation or sanitization. For example:

String username = request.getParameter("username");
String query = "(&(objectClass=user)(sAMAccountName=" + username + "))";

An attacker could input a specially crafted username like *)(uid=*))(|(uid=*; to manipulate the query and retrieve unauthorized records.

Prevention Techniques

To prevent LDAP injection, apply the following techniques:

• Use prepared statements or parameterized queries.
• Validate and sanitize all user inputs.
• Limit user permissions in the LDAP directory.
• Use LDAP APIs that provide built-in query sanitization.
• Employ logging and monitoring for abnormal activity.

Best Practices

Implement the following best practices for enhanced security:

1. Always validate input against a defined format.
2. Use whitelisting instead of blacklisting.
3. Regularly review and update security policies.
4. Perform security testing, including penetration testing.
5. Educate developers about secure coding practices.

FAQ