Cross-site scripting (XSS) is the most common form of web application vulnerability.
Cross-site scripting (XSS) is a type of vulnerability that allows attackers to inject malicious code into web applications. XSS attacks present a variety of challenges for both developers and security professionals but they can be prevented by taking steps to prevent attackers from inserting malicious scripts into web applications.
(I would be using Nodejs on the side of the codes, This shouldn’t discourage you if you are using any other backend framework, it still applies to you (not necessarily the terms).
XSS can occur due to many reasons including placing special characters in URLs and HTML forms, sending user input through email or messengers, and even fully injecting malicious code into an existing website.
This can happen on any kind of website that doesn’t control user input. The most common form of XSS exploits can be viewed in different ways: by passing through HTML forms, via email, or by simply visiting compromised websites. XSS is a leading cause of security issues for web applications and servers across internet platforms.
An Instance of XSS flaws
I created a simple form with just Html and CSS that displays what happens in a web application that is prone to cross-site scripting. An attacker attaches a script tag to the text area of the form.
An Instance of XSS flaws
I created a simple form with just Html and CSS that displays what happens in a web application that is prone to cross-site scripting. An attacker attaches a script tag to the text area of the form.
I created a simple form with just Html and CSS that displays what happens in a web application that is prone to cross-site scripting. An attacker attaches a script tag to the text area of the form.
Looking at this form, you could see I inputted an event listener (onmouseover) which gets triggered once the user hovers over the HTML tag. It triggers the alert function with the text “Wuff”. This is just a simple code that runs on a web browser on a site that’s prone to cross-site scripting. In some cases where there is authentication in play, an attacker can input codes that can extract the cookies of the user where the session is stored which keeps the user authenticated and could use the user’s cookies to impersonate the user.
How to Prevent XSS
To keep yourself safe from XSS, you must sanitize your input. As you know All XSS attacks affect your website through some form of client-side user input, Your application code should never output data received as input directly to the browser without checking it for malicious code. I will outline how you could fix this:
Filtering for XSS (Sanitization):
Filtering for XSS is a security feature that allows you to block malicious content from being displayed on your site. This blocks code from running on the server, preventing website attacks and making it impossible for an attacker to execute malicious code remotely. This filter would remove dangerous keywords, for example, the infamous