As the world continues to become more digital-first, individuals and organizations alike are starting to understand the value of cybersecurity. with so much of our life online, investing in ways to protect every piece of personal and professional data is not only important but necessary. This is especially true for businesses that engage and transact with consumers on any digital platform – from a basic marketing website to something as complex as an eCommerce site. 

This is the very reason it is vital for both small businesses and big corporations to consistently educate themselves on the most common cyberattacks out there. A good basis is OWASP’s top 10 vulnerabilities. The Open Web Application Software Project is an international non-profit organization dedicated to providing its global community with free resources in the field of cybersecurity, particularly web applications. One of their most referenced articles is the OWASP Top 10 which is a standard data-driven awareness document listing down the most critical cybersecurity risks to web applications. It is widely regarded and recognized by developers and cybersecurity experts as the initial step towards a more secure coding strategy. 

In this article, we will be discussing one of the top 10 cyber threats on the list- XSS attacks. 

What are XSS Attacks? 

XSS Attacks is an abbreviation of “Cross-Site Scripting”, an injection attack in which a hacker executes a certain type of data insertion, like a malicious script, into the content of a website.

Cross-site scripting (XSS) is a type of injection attack in which a threat actor inserts data, such as a malicious script, into content from trusted websites. The malicious code is then included with dynamic content delivered to a victim’s browser. These codes can be executable in various languages such as Java, HTML, and Ajax. XSS attacks are not direct to a user victim, but rather exploit a website a user might use by circumventing the policies that segregate one’s website from another. Through XSS, an attacker can steal user data and pretend to be the user to carry out certain actions.

Types of XSS Attacks

To know the right cybersecurity strategies and tools to utilize against Cross-site Scripting, it’s first important to know the various types of XSS Attacks and how hackers work their way through web applications to execute these malicious codes. Listed below are the three most common types of XSS attacks: 

1. Reflected Cross-site Scripting

Reflected Cross-site Scripting is the most common type of XSS attack. This kind of XSS attack uses phishing or other social engineering methods in order to lure unknowing users into making a request to a website or server that has the XSS payload script. In a reflected XSS attack, the malicious script comes from the current HTTP request.

2. Stored Cross-site Scripting

With Stored XSS, on the other hand, the malicious script comes from the website’s database. It is also known as “persistent XSS” and is considered as the most damaging among the types of XSS attacks. With Stored XSS, the payload script becomes permanently stored on the intended application; be it a database, a message board, or even a comment field. This means that the XSS is served as a persistent part of the target web page that when a user navigates will trigger the malicious script to be executed. 

3. DOM-based Cross-site Scripting

Widely regarded as the most advanced of the XSS attacks, DOM-based Cross-site Scripting happens when the client-side script of the target web application writes user-provided data to the DOM. From there, it then reads the data from the DOM which will then deliver it to the user’s browser. If the web application doesn’t have the right data security protocols, the attacker can easily inject a malicious script to be stored as part of the DOM that will then be executed when the data is read back from it. 

The Risks of XSS Attacks

XSS Attacks, when executed right, can exploit a web application’s vulnerability which can:

  • impersonate a user or an action by a user
  • carry out data breaches
  • steal a user’s login credentials
  • inject malicious functionality into a website or web application
  • deface a website or page

How to Protect a Website or Web Application from XSS Attacks

Now that you know the common types of XSS attacks as well as their risks, here is what you can do to prevent your website or web application from Cross-site Scripting: 

1. Update Software and Plugins

Updates on web software and plugins are done to improve not just overall functionality and efficiency, but as efforts to patch security vulnerabilities as well. Audit all website applications or schedule regular maintenance and update installations to minimize, if not completely eliminate XSS vulnerabilities. 

2. Validate Form Input Fields

As entry points of data, form input fields are probably one of the most vulnerable parts of any website or web application. By validating these, you are performing an additional security protocol that might just be what will save your site and your client’s data from XSS attacks. HTML form validation is usually done through JavaScript in which you, as a site or application owner, can also dictate what sort of data a client should provide to match the requirement of the fields. This client-side form validation ensures that you will not make it easy for attackers to input and submit malicious data to your server. 

3. Invest in Cybersecurity

Given that consistently checking your website or web application is necessary to protect it from XSS attacks, a great investment would be in a fully automated, cloud-based vulnerability assessment tool like SecureBrain’s GRED Web Security. With a security tool like this, you can verify and find critical vulnerabilities round-the-clock through daily website scanning, email alerts, and proper attack mitigation. 

If you’re looking to take extra measures to keep your website safe against malicious content and XSS attacks, please don’t hesitate to reach out to the cybersecurity experts here at SecureBrain.