In a modern world, Internet-based attacks are common and plentiful. This isn’t a good thing by any means, but there are many different forms of attacks which can be damaging to someone’s financial position or make their sensitive data at risk of being stolen. One such type of attack is called Cross-Site Scripting or simply XSS. Despite being one of the most common forms of attack vectors, it remains shrouded in mystery. We’re going to take a look at what it is, so you’re well informed on what could happen.
So, what is Cross-Site Scripting?
What attackers need to do is to divert the people using the site to the area of the site which has been infected with the malicious script, which is also commonly referred to as the payload. When the page loads within the browser of the victim, they will find that the script will execute without any knowledge or indication, which means that almost every time you will not know that the attacker is even introducing the payload, or that you’re being infected with it.
What does Cross-Site Scripting do?
There are a lot of different things which Cross-Site Scripting can do, all of which can be very harmful to an individual or organisation. If the code is implemented correctly and the malicious script is successfully added, then you’ll find that a lot of private information is not safe. First of all, hackers can get access to your cookies, which are things you agree to have stored on sites when you use them. This does include session cookies, which can then lead to the attacker taking over the entire session, and manipulating what you see.
By introducing a malicious script into the system, someone could take your sensitive information, and then forward it away from the website you’re on and send it to a site they control, thus gaining that information. Overall, Cross-Site Scripting is something which is one of the most common attack vectors in WordPress, and even for every single site across the internet. Even internet giants like Google could be at risk of getting infected if they didn’t have people and programs designed to find external scripts and then destroy them.
If your browser loads a page with a payload inside of it, then you may, in fact, see yourself forced to surrender personal information without any knowledge that you’re being made to do so. Cross-Site Scripting, or XSS, is one of the most common ways that attackers can tamper with a website and take personal details, so if you’ve ever lost money or had information used without your consent, then it may well be worth considering this as the explanation.
How to deal with XSS in WordPress?
Any non-validated user input without proper HTML encoding may lead to XSS injection. When writing a plugin for WordPress, you need to sanitize and escape the user input to ensure that it is safe to use. There are built-in functions such as
update_option( 'my_option', sanitize_text_field( 'user_input_goes_here' ) ); // Cleaning the user input echo esc_attr( get_option( 'my_option ') ); // Escaping for HTML attributes and preventing XSS