Crack a Weak Telnet Password

Introduction

In this challenge, you'll step into the role of a junior pentester tasked with cracking a weak Telnet password. A legacy Telnet server is exposed at 127.0.0.1, and your mission is to leverage Hydra to identify valid credentials from provided username and password lists, demonstrating the inherent risks associated with weak security practices.

The challenge involves setting up a vulnerable Telnet server with predefined users and passwords, creating username and password lists, and then launching a Hydra attack against the Telnet service. You'll need to document the successful username and password combination discovered by Hydra in a credentials.txt file, adhering to specific formatting and output requirements.

Crack a Weak Telnet Password

A legacy Telnet server is exposed. As a junior pentester, your task is to use Hydra to find valid credentials from provided username and password lists to demonstrate the risk. The server IP is 127.0.0.1.

Tasks

• Launch a Hydra attack against the Telnet service on 127.0.0.1 using usernames.txt and passwords.txt to discover a working login.
• Document the successful username and password combination identified by Hydra.

Requirements

1. You must execute the Hydra command from the ~/project directory.
2. Use the usernames.txt file for usernames and the passwords.txt file for passwords.
3. Target the Telnet service running on 127.0.0.1.
4. Save the Hydra output to a file named hydra_output.txt in the ~/project directory.
5. Create a file named credentials.txt in the ~/project directory containing the successful username and password combination found by Hydra. The format should be username:password.

Examples

If Hydra successfully finds the credentials user1 and password, the credentials.txt file should contain:

user1:password

Hints

• Use the -L and -P flags in Hydra to specify the username and password files, respectively.
• Use the -o flag to save the Hydra output to a file.
• Use grep to extract the successful login from the Hydra output file.
• Remember to specify the Telnet service using telnet://127.0.0.1.

Summary

In this challenge, a vulnerable Telnet service running on 127.0.0.1 was targeted using Hydra to crack weak credentials. The setup involved installing necessary packages like hydra, xinetd, and telnetd, configuring the Telnet service, creating test users with weak passwords, and generating username and password lists.

The task focused on launching a Hydra attack using the created lists against the Telnet service, saving the output to hydra_output.txt, and documenting the successful username and password combination (user2:123456) in a credentials.txt file, demonstrating the vulnerability of weak passwords in legacy systems.