Speednet Hack The Box Walkthrough: A Comprehensive Guide

by Jhon Lennon 57 views

Hey guys! Ready to dive into another exciting Hack The Box challenge? Today, we're tackling Speednet, a box that will test your web application skills and your ability to think outside the box. This walkthrough will provide you with a step-by-step guide, ensuring you understand each stage and learn valuable techniques along the way. So, buckle up, and let's get started!

Initial Reconnaissance

First things first, let's get our hands dirty with some initial reconnaissance. Reconnaissance is the crucial first step in any penetration test or CTF challenge. It's all about gathering as much information as possible about the target before you start trying to exploit it. This information will guide your attack strategy and help you identify potential vulnerabilities. For Speednet, we'll start with the basics: an Nmap scan.

Nmap Scan

Nmap, or Network Mapper, is your best friend when it comes to network scanning. It helps you discover hosts and services on a network. We'll use it to identify open ports and running services on the Speednet box. Fire up your terminal and run the following command:

nmap -sV -sC -p- <target_ip>

Let's break down this command:

  • -sV: This option tells Nmap to probe open ports to determine service/version information. Knowing the software versions running on the target is incredibly useful because it allows you to search for known vulnerabilities associated with those specific versions.
  • -sC: This option enables the Nmap Scripting Engine (NSE) to run a set of default scripts against the target. These scripts can automatically detect vulnerabilities, gather more information about the services, and even attempt to exploit some common issues.
  • -p-: This tells Nmap to scan all 65535 ports on the target. While this takes longer than scanning the default 1000 ports, it ensures that you don't miss any potentially interesting services running on unusual ports.
  • <target_ip>: Replace this with the actual IP address of the Speednet box on Hack The Box.

After the scan completes, you should see something like this (the exact output might vary slightly):

Port 22/tcp  open  ssh     OpenSSH 8.2p1 Ubuntu 4ubuntu0.5 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
|   3072 SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
|_  256 SHA256:yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
Port 80/tcp  open  http    nginx 1.18.0
| http-robots.txt: See robots.txt
| http-title: Speedtest
|_http-server-header: nginx/1.18.0

This tells us a few important things:

  • Port 22: SSH is running. While we won't focus on SSH initially, it's good to keep in mind for potential privilege escalation later.
  • Port 80: HTTP is running, which means there's a web server. This is our primary focus for now.

Exploring the Web Server

With the Nmap scan revealing an HTTP service, it's time to point our browser to the Speednet box. Open your web browser and navigate to http://<target_ip>. You should see a simple speed test website. Take a look around! What do you notice? Are there any immediately obvious vulnerabilities? Inspect the page source (usually by right-clicking and selecting "View Page Source" or pressing Ctrl+U). Look for comments, hidden fields, or any interesting JavaScript files that might give you a clue.

Also, don't forget to check the robots.txt file, which Nmap helpfully pointed out. Navigate to http://<target_ip>/robots.txt. This file tells search engine crawlers which parts of the website they shouldn't index. Sometimes, it can reveal hidden directories or files that the developers didn't want to be publicly accessible. This is a common place to find interesting information.

In the case of Speednet, the robots.txt file might lead you to a specific directory that contains further clues. Keep an eye out for anything that seems out of the ordinary or potentially vulnerable. Remember, the key to successful reconnaissance is thoroughness and attention to detail.

Uncovering Hidden Functionality

After our initial exploration, let's dig a little deeper to uncover any hidden functionality within the Speednet application. This often involves using tools like Burp Suite or OWASP ZAP to intercept and analyze the web traffic. We're looking for interesting API endpoints, hidden parameters, or any unusual behavior that could lead to a vulnerability.

Burp Suite: Your Web Interception Ally

Burp Suite is a powerful tool for web application security testing. It acts as a proxy, allowing you to intercept and modify HTTP requests and responses between your browser and the web server. This is invaluable for understanding how the application works and identifying potential vulnerabilities. To get started with Burp Suite, you'll need to configure your browser to use it as a proxy.

  1. Configure Burp Suite: Open Burp Suite and go to the "Proxy" tab. Make sure the "Intercept" button is turned on. By default, Burp Suite listens on http://127.0.0.1:8080.
  2. Configure your Browser: In your browser settings, search for "proxy settings" or "network settings." Configure your browser to use a manual proxy with the following settings:
    • Address: 127.0.0.1
    • Port: 8080

Now, when you browse to the Speednet website, your browser will send all requests through Burp Suite, allowing you to intercept and examine them.

Analyzing Web Traffic

With Burp Suite configured, start interacting with the Speednet application. Run a speed test and observe the HTTP requests and responses in Burp Suite. Pay close attention to the following:

  • Request Parameters: Look for any interesting parameters in the GET or POST requests. Are there any parameters that seem unusual or potentially vulnerable to injection attacks?
  • Cookies: Examine the cookies being set by the application. Are they secure? Do they contain any sensitive information?
  • API Endpoints: Identify any API endpoints being used by the application. These endpoints might reveal hidden functionality or provide opportunities for exploitation.
  • Response Headers: Check the response headers for any security-related information, such as the X-Frame-Options or Content-Security-Policy headers. Missing or misconfigured headers can indicate potential vulnerabilities.

By carefully analyzing the web traffic, you might discover a hidden API endpoint that allows you to perform actions that are not normally available through the user interface. For example, you might find an endpoint that allows you to view or modify the speed test results of other users. This could be a major security vulnerability.

Exploitation: Gaining Access

Alright, so after some digging, you might stumble upon an interesting API endpoint. This endpoint might be responsible for handling speed test results, and it could be vulnerable to some form of injection. This is where things get exciting! Let's try to exploit this vulnerability to gain access to sensitive information or even execute arbitrary code on the server.

Crafting Malicious Payloads

To exploit the vulnerability, we'll need to craft a malicious payload. This payload will be designed to take advantage of the flaw in the API endpoint and allow us to achieve our goals. The specific payload will depend on the type of vulnerability, but here are a few common techniques:

  • SQL Injection: If the API endpoint is vulnerable to SQL injection, we can inject malicious SQL code into the request parameters to bypass authentication, extract sensitive data, or even execute arbitrary commands on the database server. Tools like sqlmap can be very helpful for automating SQL injection attacks.
  • Command Injection: If the API endpoint executes system commands based on user input, we can inject malicious commands into the request parameters to execute arbitrary code on the server. This is a very dangerous vulnerability that can lead to complete system compromise.
  • Cross-Site Scripting (XSS): If the API endpoint doesn't properly sanitize user input before displaying it on the page, we can inject malicious JavaScript code into the request parameters. This code will be executed in the context of other users' browsers, allowing us to steal their cookies, redirect them to malicious websites, or even deface the website.

Sending the Payload

Once we've crafted our malicious payload, we'll need to send it to the vulnerable API endpoint. We can use Burp Suite to modify the request and inject our payload into the appropriate parameter. Make sure to URL-encode the payload if necessary to prevent it from being misinterpreted by the server.

After sending the payload, carefully examine the response from the server. Look for any error messages or unusual behavior that might indicate that the exploit was successful. If you're lucky, you might gain access to sensitive information, such as database credentials or API keys. You might even be able to execute arbitrary code on the server, giving you complete control over the system.

Privilege Escalation

Now that we've gained initial access to the Speednet box, it's time to escalate our privileges and become root. This usually involves finding a vulnerability in a system service or misconfigured file permissions that allow us to gain elevated privileges.

Enumerating the System

First, we need to enumerate the system to gather information about the operating system, installed software, and file permissions. We can use a variety of tools and techniques for this, including:

  • uname -a: This command displays information about the kernel version and architecture.
  • id: This command displays the current user's ID and group memberships.
  • sudo -l: This command lists the commands that the current user can execute with sudo.
  • find / -perm -4000 -type f 2>/dev/null: This command searches for files with the setuid bit set. These files can potentially be used to escalate privileges.
  • ps aux: This command displays a list of running processes. Look for any processes running with elevated privileges or owned by other users.

By carefully examining the output of these commands, we might discover a vulnerability that can be exploited to gain root access. For example, we might find a file with the setuid bit set that can be used to execute arbitrary code with root privileges. Or, we might find a misconfigured service that can be exploited to gain root access.

Exploiting the Vulnerability

Once we've identified a potential vulnerability, we'll need to exploit it to gain root access. The specific exploit will depend on the type of vulnerability, but here are a few common techniques:

  • Exploiting SUID Binaries: If we find a file with the setuid bit set that is vulnerable to buffer overflow or other vulnerabilities, we can exploit it to execute arbitrary code with root privileges.
  • Exploiting Kernel Vulnerabilities: If we find a vulnerability in the kernel, we can exploit it to gain root access. This usually involves writing a custom exploit that takes advantage of the kernel flaw.
  • Exploiting Misconfigured Services: If we find a misconfigured service that is running with root privileges, we can exploit it to gain root access. This might involve sending malicious requests to the service or exploiting a vulnerability in the service's code.

After successfully exploiting the vulnerability, we should obtain a root shell, giving us complete control over the Speednet box.

Conclusion

And there you have it! We've successfully completed the Speednet Hack The Box challenge. We started with initial reconnaissance, uncovered hidden functionality, exploited a vulnerability to gain initial access, and then escalated our privileges to become root. This walkthrough has provided you with a detailed guide to each step of the process, hopefully giving you a solid foundation for tackling similar challenges in the future. Remember, practice makes perfect, so keep exploring, keep learning, and keep hacking! Now go on and own those boxes, guys! You got this!