SQL injection is a common web security vulnerability that allows attackers to interfere with the queries that a web application makes to its database. This article will guide you through the steps to prevent SQL injection in your web applications.

Common Vulnerabilities

  1. Dynamic SQL: Building SQL queries using user input directly.
  2. Inadequate Input Validation: Not validating user input can lead to SQL injection.
  3. Improper Use of APIs: Using APIs without proper security measures.

Prevention Measures

  1. Use Prepared Statements: Prepared statements separate the SQL logic from the data, making it harder for an attacker to inject malicious SQL code.
  2. Input Validation: Validate all user input on the server-side before using it in a SQL query.
  3. Use ORM (Object-Relational Mapping): ORMs can help prevent SQL injection by automatically escaping inputs.

Example

Here's an example of a secure way to use prepared statements in PHP:

$stmt = $pdo->prepare("SELECT * FROM users WHERE username = :username");
$stmt->execute(['username' => $username]);

Further Reading

For more information on preventing SQL injection, you can read our comprehensive guide on Web Security.

SQL Injection