How can one prevent XSRF, SQL Injections, and cookie theft in PHP applications?

To prevent XSRF attacks in PHP applications, you can use CSRF tokens. These tokens are unique values generated for each user session and included in forms. When the form is submitted, the token is validated to ensure the request is legitimate. 

// Generate CSRF token
$csrf_token = bin2hex(random_bytes(32));
$_SESSION['csrf_token'] = $csrf_token;

// Include CSRF token in form
echo '<input type="hidden" name="csrf_token" value="' . $csrf_token . '">';

// Validate CSRF token on form submission
if ($_POST['csrf_token'] !== $_SESSION['csrf_token']) {
    // Invalid token, handle error
}
```

To prevent SQL injections, you should always use prepared statements with parameterized queries. This ensures that user input is properly sanitized and prevents malicious SQL code from being executed.

```php
// Prepare SQL statement with placeholders
$stmt = $pdo->prepare("SELECT * FROM users WHERE username = :username");

// Bind parameters and execute query
$stmt->bindParam(':username', $_POST['username']);
$stmt->execute();
```

To prevent cookie theft, you can set the 'secure' and 'httpOnly' flags when setting cookies. The 'secure' flag ensures that cookies are only sent over HTTPS connections, while the 'httpOnly' flag prevents cookies from being accessed via JavaScript.

```php
// Set secure and httpOnly flags for cookies
setcookie('session_id', $session_id, time() + 3600, '/', '', true, true);

Keywords

XSRF SQL Injection cookie theft CSRF token prepared statements

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