Walking an Application - THM

In-Built Browser Tools: Importance and Types

Importance of In-Built Browser Tools.

In-built browser tools are essential for web developers and penetration testers as they allow for the inspection, debugging, and analysis of web applications directly within the browser. These tools provide a detailed view of the website's structure, resources, and interactions, enabling users to identify and exploit potential vulnerabilities manually that automated tools might miss.

Types of In-Built Browser Tools and Their Importance

1. View Source

   • Importance: Viewing the page source allows users to see the raw HTML, CSS, and JavaScript code returned from the server. This can help in understanding the basic structure of the webpage and identifying any embedded comments or hidden elements that might provide useful information.
   • How to Use: Right-click on the webpage and select "View Page Source" or use view-source: before the URL in the address bar.

2. Inspector

   • Importance: The Inspector tool provides a live view of the HTML and CSS as rendered by the browser. It allows users to see the effects of CSS and JavaScript on the page and make temporary changes to understand how elements interact with each other.
   • Key Features:
     • Element Inspection: View and modify HTML elements.
     • CSS Styles: Edit and experiment with CSS rules in real-time.
     • Live Updates: See changes reflected immediately without refreshing the page.
   • How to Use: Right-click on any element and select "Inspect" or open the developer tools and select the "Elements" tab.

3. Debugger

   • Importance: The Debugger tool allows for the inspection and debugging of JavaScript code. Users can set breakpoints to pause code execution and step through code line by line, which is invaluable for understanding how scripts work and identifying issues.
   • Key Features:
     • Breakpoints: Set points in the code where execution will pause.
     • Call Stack: View the order in which functions are called.
     • Variable Inspection: Examine the values of variables at different execution points.
   • How to Use: Open developer tools and select the "Debugger" (Firefox, Safari) or "Sources" (Chrome) tab.

4. Network

   • Importance: The Network tool tracks all network requests made by the webpage, including HTML, CSS, JavaScript files, AJAX requests, and more. It helps in understanding how data is transmitted and can identify any security issues in data transmission.
   • Key Features:
     • Request and Response Headers: View the details of network requests and responses.
     • Timing Information: Analyze the load times and performance of resources.
     • AJAX Requests: Monitor background requests made by the webpage.
   • How to Use: Open developer tools and select the "Network" tab. Reload the page to see the requests being made.

Practical Application

In the provided tasks, the use of these in-built browser tools is demonstrated to:

• Identify hidden elements and comments in the source code (View Source).
• Manipulate the DOM to reveal hidden content (Inspector).
• Debug JavaScript to intercept and analyze execution (Debugger).
• Monitor network requests to understand data flow and capture transmitted data (Network).

These tools collectively allow penetration testers to conduct thorough manual reviews of web applications, uncovering vulnerabilities that automated scans might miss. Understanding and effectively using these tools is crucial for anyone involved in web development or cybersecurity.