What are the common pitfalls to avoid when implementing user authentication and authorization logic in PHP scripts?

One common pitfall to avoid when implementing user authentication and authorization logic in PHP scripts is failing to properly sanitize user input, which can lead to SQL injection attacks. To prevent this, always use prepared statements when querying the database to prevent malicious code execution. 

// Example of using prepared statements to prevent SQL injection
$username = $_POST['username'];
$password = $_POST['password'];

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

$user = $stmt->fetch();
if ($user) {
    // User authentication successful
} else {
    // User authentication failed
}

Keywords

SQL injection password hashing session management CSRF protection role-based access control

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