WordPress XSS Protection: 4 Ways to Protect Your Site

Malicious hackers have always presented a problem for WordPress users. However, the rise of cross-site scripting – also known as XSS attacks – is particularly worrisome. Between stolen data and lost user trust, WordPress XSS protection can seem difficult to achieve.

Fortunately, you don’t have to feel powerless against these looming threats. By taking a few precautions, you can help protect your website from XSS attacks and keep your data secure.

An introduction to WordPress XSS attacks

There are unfortunately a lot of ways that hackers can compromise your data. In most cases, these attacks start by gaining access to your site. XSS attacks in particular work by taking advantage of vulnerabilities in user interactions.

Once a hacker has found a weak point, they can then add their own code to your site. Then, when a user interacts with that page, the bad code will run on the client side. These new lines act as malicious instructions that tell your site to share confidential data.

Code like this can do anything, from stealing account details from your users to rewriting the content of your whole website. No matter what the exact impact is, it’s likely to have a number of damaging effects on you and your users.

For example, a security breach can compromise your users’ trust in you. This can be especially true if sensitive customer data like credit card numbers has been stolen. The malicious actor may also steal addresses, phone numbers, and emails, leading to a barrage of spam for your unhappy audience.

The wide-ranging and serious consequences of these hacks make XSS assaults a force to be reckoned with. It’s normal to feel a little powerless against them. However, the good news is that you can fight back by taking a few sensible precautions.

Four ways to improve WordPress XSS protection

Let’s look at a few ways to take XSS protection into your own hands. For maximum effectiveness, we recommend that you apply as many of these precautions as you can.

• Keep all of your software updated
• Use a powerful web application firewall (WAF)
• Validate and sanitize user data
• Add a content security policy to your header

1. Keep all your software updated 🔔

You probably already know that updating your programs periodically helps to keep everything working properly. However, it also comes with serious security benefits.

Unfortunately, not all code is perfect. When developers find a vulnerability in their work, they release a patch to fix it. By updating your programs with the new and improved code, you’re removing opportunities for hackers to access your page.

If you’re not updating software as soon as possible, this means that you’re leaving open doors for malicious actors to enter through. Therefore, it’s so important to stay on top of all your updates. This includes plugins, themes, and even the WordPress software itself.

For plugins and themes, you can navigate to their respective sections from your left-hand dashboard menu. Then, you can click the Update Available tab to see which programs need a quick refresh.

Meanwhile, WordPress will automatically update itself for security fixes. However, bigger updates will require you to follow a prompt on your homepage and set the update into motion. If you’re not getting these prompts, you can always manually update your WordPress software instead.

To see your site’s current update status, you can go to Dashboard > Updates:

In this example, the core WordPress files are up to date, but there are 15 plugins that need to be updated.

If you have trouble keeping an update schedule, consider enabling automatic updates for your plugins and themes. You can do this directly from your WordPress dashboard. This can help protect your site from XSS attacks, even if you forget to check your update status every once in a while.

For more details, you can check out our guide on how to update WordPress safely.

2. Use a powerful web application firewall (WAF) 📛

Like many other hacks, WordPress XSS attacks work by manipulating weaknesses in your site. However, this process tends to produce irregular network activity. As such, they can potentially be detected and prevented by a high-quality web application firewall (WAF).

For example, let’s say someone has launched an XSS assault on your site to retrieve login information. A WAF may be able to flag this request as malicious. It can then ban the source of the attack, stopping hackers before they can obtain sensitive data.

However, WAFs don’t just work against XSS attacks. They can also be a valuable tool against any assault with irregular activity, such as brute force attacks. As such, we recommend you take the time to find a high-quality solution.

When you’re looking for a WAF, consider asking yourself the following questions:

• Are the firewall rules regularly updated to account for new threats and vulnerabilities?
• Does it provide useful reports and attack alerts?
• Does it keep the site secure without slowing it down?
• Can it automate crucial maintenance tasks?

If the answer to these is ‘yes’, you’re likely looking at an effective tool. For more XSS protection, you may want to consider choosing a general security plugin that includes a firewall. That way, you can cover all your bases against potential attacks.

Wordfence is one popular security plugin that includes a regularly updated WAF – you can read our Wordfence guide to learn how it works.

3. Validate and sanitize user data 💾

If you’re like most site owners, you enable your users to interact with your site. Whether they’re posting comments or submitting credit card numbers, user submissions can be a crucial part of any website.

Unfortunately, these user interactions present opportunities for hackers to launch XSS attacks. This is because user input fields give access to your site by design. However, you can validate and sanitize the data to make sure nothing malicious comes your way.

Fortunately, most quality WordPress plugins and themes already do this. That means that instead of learning the technical aspects of validation and sanitization, you can just focus on choosing well-made programs instead.

To make sure you’re picking software that confirms user data, we recommend that you pay close attention to the ratings and support aspects of the plugin:

Positive reviews are proof that many people actively use the program without major issues. By the same token, support issues with recent responses can show that the development team is actively reviewing and fixing any vulnerabilities.

If you have any doubts about how well your site holds up to this method, we encourage you to consult a web developer. These experts can ensure that your website is vetting submitted data in a way that offers XSS protection.

4. Add a content security policy to your header 🔒

A content security policy is a piece of code that decides which dynamic resources are allowed to load. In short, it can detect any malicious XSS attacks and prevent them from actually being carried out. Thus, including one in your header is an important security step.

This process may sound technical, but it’s actually not that difficult. All you need to do is add some code to your WordPress files. As such, you’ll need to make sure you have a file transfer protocol (FTP) client set up and connected to your site before you begin.

To begin, open up your FTP client. Next, find the .htaccess file within your root folder.

Download a copy of the file so that you have a backup just in case something goes wrong. Then, edit the .htaccess file on your server with your text editor of choice:

Scroll down to the bottom, past the # END WordPress notice. Once you’re there, copy and paste the following code from Patchstack into your file:

Content-Security-Policy default-src 'none'; script-src 'self'; connect-src 'self'; img-src 'self'; style-src 'self';

When you’re finished, save your work. That’s it! You should now have a content security policy on your site.

Implement WordPress XSS protection today

🛡️ In this article, we covered four methods for improving your site’s WordPress XSS protection:

For some other ways to protect your WordPress site, you can check out our ten tips for WordPress security, plus our specific guides on protecting WordPress from common attacks such as DDoS attacks, SQL injection, and brute force attacks.

Do you have any questions about defending against XSS attacks in WordPress? Let us know in the comments section below!