How to Prevent Cross-Site Scripting in PHP

User input forms on our website can be vulnerable to cross-site scripting (XSS) attacks if we aren’t extremely careful.

Thankfully, there’s an easy way to protect our text inputs from cross-site scripting attacks: we can simply call a free security API (using a few lines of complementary PHP code examples) that checks for XSS threats and automatically normalizes the input.

This way, we’ll get information about XSS attacks when they occur, and we’ll also immediately neutralize XSS threats before they can make an impact.

We can structure our API call in two quick steps.

First, we need to install the PHP client with Composer by executing the below command:

composer require cloudmersive/cloudmersive_security_api_client

Next, we need to briefly turn our attention to API call authorization. We’ll need a free Cloudmersive API key to authorize our requests, and this will allow us to make a limit of 800 API calls per month with zero additional commitments.

With our API key ready to go, we can now include the below code to call the XSS detection and normalization function:

<?php
require_once(__DIR__ . '/vendor/autoload.php');

// Configure API key authorization: Apikey
$config = Swagger\Client\Configuration::getDefaultConfiguration()->setApiKey('Apikey', 'YOUR_API_KEY');



$apiInstance = new Swagger\Client\Api\ContentThreatDetectionApi(
    
    
    new GuzzleHttp\Client(),
    $config
);
$value = "value_example"; // string | User-facing text input.

try {
    $result = $apiInstance->contentThreatDetectionProtectXss($value);
    print_r($result);
} catch (Exception $e) {
    echo 'Exception when calling ContentThreatDetectionApi->contentThreatDetectionProtectXss: ', $e->getMessage(), PHP_EOL;
}
?>

That’s all the code we’ll need — now we have a simple, low-code solution for detecting and removing XSS threats from our website’s text input fields.