Hacking Cisco Switches with Kali Linux

In this tutorial, we will explore the intriguing world of ethical hacking by demonstrating how to hack Cisco switches using Kali Linux. Before diving into the technical details, it's essential to note that this knowledge should only be used responsibly and ethically to protect networks and systems, not exploit them. So, let's get started on this enlightening journey into network security.

Setting the Stage

In a prior guide, we discussed how to download and install Kali Linux on a Windows 10 computer, a crucial step in our hacking endeavors. If you haven't completed this setup yet, make sure to check out the linked guide for guidance.

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Introduction to Yersinia

Our tool of choice for this demonstration is Yersinia, a versatile framework designed for layer 2 attacks. Yersinia enables us to target various network protocols, including:

- Spanning Tree

- CDP (Cisco Discovery Protocol)

- DTP (Dynamic Trunking Protocol)

- HSRP (Hot Standby Router Protocol)

- 802.1q

- 802.1X

- ISL (Inter-Switch Link)

- VTP (VLAN Trunking Protocol)

While Yersinia can be used to target a range of devices, it's particularly well-suited for Cisco networks, as it can exploit Cisco proprietary protocols like CDP, DTP, and HSRP.

Our Network Setup

In our lab environment, we have a Cisco switch, specifically a Catalyst 2960cg switch. This switch serves as the focal point of our demonstration. Connected to it are two devices:

1. A Windows 10 laptop (Physical) connected to Port 1.

2. A MacBook (Physical) connected to Port 2.

Both of these devices are connected to the switch via Ethernet cables. Additionally, we've established a console connection to the switch using a USB connection. To streamline our demonstration, we're remotely controlling both the MacBook and Windows computer from a local Mac.

Installing Yersinia

To start using Yersinia, we first need to install it on our Kali Linux machine. Yersinia is no longer installed by default in recent versions of Kali Linux, such as 2019.3. To install it, follow these steps:

1. Open a terminal and run `apt-get update` to update package references.

2. Install Yersinia by running `apt-get install yersinia`.

3. Once the installation is complete, you can check if Yersinia is properly installed by typing `yersinia -h`. This command will display the available options and commands.

Launching Yersinia

Now, let's explore how to use Yersinia to perform basic network attacks:

1. Launch Yersinia's graphical user interface by entering `yersinia -G` in the terminal.

2. In the GUI, select your desired attack. For our demonstration, we'll initiate a CDP attack.

3. Observe the attack log and notice how Yersinia sends CDP packets to flood the CDP neighbor table of the switch.

4. On the switch, you'll witness a significant increase in CDP neighbors, even though there are no physical devices connected.

Ethical Considerations

Before concluding, it's crucial to emphasize that ethical hacking is about safeguarding networks and systems, not exploiting vulnerabilities. As you continue to explore the world of hacking, remember to use your knowledge responsibly and within the bounds of the law.

Conclusion

This tutorial offered a glimpse into the realm of ethical hacking, where we utilized Kali Linux and Yersinia to demonstrate basic layer 2 attacks on a Cisco switch. These foundational skills can be invaluable for those looking to enhance their network security expertise.

In future guides, we'll delve deeper into advanced hacking techniques and explore larger network topologies. If you found this tutorial enlightening, subscribe to our channel, like the video, and hit the notification bell for updates.

As you embark on your ethical hacking journey, always remember to tread carefully and ensure your actions align with ethical principles and legal boundaries. Responsible hacking can be a powerful tool in securing the digital world.