XSS – Merry XSSMas

This room was released on day eleven of the event and focuses on Cross Site Scripting (XSS).

Task 1 Introduction

Read a brief setup with a tiny bit of story.

Spin up the Attack Box and a Virtual Machine.

There is no question or answer for this section.

Task 2 Leave the Cookies, Take the Payload

Access the web app dashboard from the Attack Box using the web browser.

Read about Cross Site Scripting (XSS), a vulnerability that arises from improper validation of user input that can result in it being interpreted as code and run.

• Reflected XSS is loaded immediately and results displayed to the user.
• Stored XSS is stored on the web server and delivered to all users.

Stored

Enter a reflected XSS payload into search box and submit.

<script>alert('Reflected Meow Meow')</script>

Look below the search results on the page for the flag.

THM{Evil_Bunny}

Enter a stored XSS payload into the comment box and submit.

<script>alert('Stored Meow Meow')</script>

Look below recent messages on the page for the flag.

THM{Evil_Stored_Egg}