XSS Attack

Lily is learning about web security and encounters various types of attacks. She wonders which of the following attacks is not a Front End attack.

• Directory Access

• Cross-Site Request Forgery

• Denial of Service (DoS) Attack

• Using Content Security Policy

Answer explanation

Directory Access is a back-end attack that targets server resources, while the other options, like Cross-Site Request Forgery and Denial of Service, are front-end attacks affecting user interactions and service availability.

Avery was learning about web security and came across a term that described a type of attack where malicious scripts are injected into web pages viewed by other users. What does XSS Attack stand for?

• Cross Server Scripting

• Cross-Site Scripting

• Cross Service Scripting

• Cross Secure Scripting

Answer explanation

XSS stands for Cross-Site Scripting, a type of attack where attackers inject malicious scripts into web pages. This allows them to execute scripts in the context of another user's session, compromising security.

During a school project, Scarlett discovered that a website used by her classmates, including Benjamin and Avery, had a vulnerability. This vulnerability allowed malicious code to be permanently stored on the server. Each time her classmates accessed the website, they unknowingly received the harmful code. What type of XSS attack is this?

• DOM-based XSS

• Reflected XSS

• Stored XSS

• Redirected XSS

Answer explanation

The vulnerability described allows harmful code to be stored on the server, affecting all users who access the site. This is characteristic of Stored XSS, where the malicious script is saved and executed whenever the page is loaded.

During a class project, Olivia clicks on a link sent by her classmate David, which leads her to a webpage that displays a message. The message contains a script that steals her session cookies. What type of XSS occurs when malicious code is delivered to the user in an HTTP response, often through a URL parameter or a form, without being stored permanently on the server?

• Stored XSS

• Reflected XSS

• DOM-based XSS

• Injected XSS

Answer explanation

Reflected XSS occurs when malicious code is delivered via an HTTP response, often through a URL parameter, and is executed immediately without being stored on the server. This matches Olivia's scenario.

While working on a group project, Mason noticed that the web application they were using to collaborate was behaving strangely. He discovered that a malicious script was executing within the DOM document of the webpage itself, affecting their work. What type of XSS attack is this?

• DOM-based XSS

• Stored XSS

• Reflected XSS

• Session-based XSS

Answer explanation

Mason encountered a script executing within the DOM, indicating that the attack manipulated the client-side code. This is characteristic of DOM-based XSS, where the attack occurs in the browser rather than through server responses.

During a web development class, Rohan was experimenting with a new feature on his website. He noticed that when he manipulated the Document Object Model (DOM) using JavaScript, certain actions triggered unexpected behaviors without any server interaction. Among the types of XSS, which one is often harder to detect because it occurs entirely on the client side and does not require any interaction with the server?

• Stored XSS

• Reflected XSS

• DOM-based XSS

• Server-side XSS

Answer explanation

DOM-based XSS occurs entirely on the client side, manipulating the DOM without server interaction, making it harder to detect. This aligns with Rohan's experience of unexpected behaviors while using JavaScript.

Based on the code snippet below, what type of XSS attack could occur when Ethan inputs a malicious script in the search bar?

• Stored XSS

• Reflected XSS

• DOM-based XSS

• 1. Server-side XSS

Answer explanation

DOM-based XSS occurs when the client-side script manipulates the DOM based on user input. If Ethan inputs a malicious script in the search bar, it can be executed in the browser, making it a DOM-based XSS attack.

During a class project, Benjamin created a search form that takes user input and displays the results on the same page. If an attacker submits a malicious script through the search input, what type of XSS attack can this lead to?

• Stored XSS

• Reflected XSS

• DOM-based XSS

• Self-contained XSS

Answer explanation

Reflected XSS occurs when user input is immediately reflected back in the response without proper validation or sanitization. Since Benjamin's search form displays results on the same page, a malicious script can be executed, leading to this type of attack.

During a coding workshop, Hannah is working on a Next.js application where users can input their usernames. However, she realizes that the way the application handles user input might expose it to vulnerabilities. What type of XSS can the following Next.js code lead to?

• Stored XSS

• Reflected XSS

• DOM-based XSS

• Sanitized XSS

Answer explanation

The Next.js code can lead to DOM-based XSS because it manipulates the DOM directly using user input without proper sanitization, allowing malicious scripts to execute in the user's browser.

Liam is developing a React application where he needs to display user input safely. What is the best method to prevent XSS when displaying user input in React?

• Convert userInput to HTML before displaying.

• Display userInput directly in JSX as shown.

• Use dangerouslySetInnerHTML

• Use a library to "sanitize" userInput before displaying

Answer explanation

Using a library to sanitize user input is the best method to prevent XSS in React. This approach ensures that any potentially harmful scripts are removed, allowing safe display of user-generated content.