Hacking Spanning Tree with Python, Scapy and Kali Linux (Ep 2) // STP Root Bridge attack! 😀

Key Takeaways

this video is part of my series showing you how to hack networks using python i'm going to show you how easy it is to hack a network using a simple python script now if you enjoy these types of ethical hacking videos if you enjoy python if you enjoy ethical hacking if you enjoy networking please consider subscribing to my youtube channel please like this video and click on the bell to get notifications that really does help me with the youtube robots i'm uploading a lot of networking and hacking content to my youtube channel as well as programming content hopefully you enjoy this type of thing if you do please consider subscribing to my youtube channel once again okay let's get started [Music] this script will change the spanning tree root in a switched network in this demonstration i've got three cisco switches and some pcs that are part of my topology so in this example i've got a 3560 cx switch that's the bottom switch in this topology i've got a cisco 1000 series switch and a cisco 2960. in this example the cisco switch is the root switch i'm going to tell the switches that my kali virtual machine or kali virtual machine if you prefer is the route by sending bpdus or bridge protocol data units into the network we're basically going to capture bpdus off the network and we're going to forge them or change them to make the switches believe that we are the root in the spanning tree topology again this is a very simple script we're using scapy in this example have a look at my previous videos where i discuss escapee in more detail in this video i'm simply showing you how i can manipulate the spanning tree root using scapy and a few lines of python code so what we're going to do initially is capture the spanning tree frames of the wire we are looking for traffic going to this well-known mac address which is the mac address of spanning tree we are then going to change the source mac address the root id and the root mac to this we're setting the bridge id to this and the bridge mac to this basically i'm sending a frame back into the network saying that i am the root spanning tree elects the root bridge really important in networks it elects the root bridge based on the lowest priority and lowest mac address currently in my network if i look at the 3560 cx switch the root bridge has this priority and this mac address this switch is not the root its root port is out of gigabit zero two in other words it's pointing to the 2960. on the 2960 switch show spanning tree this switch is the root switch once again has this priority has this mac address so what i'm going to do is i'm going to announce that i have the lowest priority lowest mac address so i'll run the script just to show you what happens to do that i'm going to use kali or kali linux i'm running this in a virtual machine just makes it easier for people to follow me and makes it easier to record so let's hack the spanning tree root i'll paste the script in again it's only a few lines of code it's literally one two three four five six seven eight nine lines of code very basic script i'm gonna use sudo to give me admin privileges stp root hack dot py that's the script that i'm going to run put in my password so previously the root in the network was this now the root has a priority of zero mac address of this and the root port on the 3560 has changed from gigabit zero two to gigabit zero five looking at my topology that's the kali the virtual machine the kali pc or virtual machine has become the root of my spanning tree network it's as simple as that to change the route in a network you don't want this to happen you want to implement security mechanisms to stop this so you want to implement root guard as an example to stop this kind of nonsense happening now in this example i'm using my own equipment i'm using my own equipment here i'm not hacking someone else's network you need to learn python you need to learn networking if you want to become an ethical hacker or a network engineer this kind of stuff gives you a lot of power but only use it for good only do ethical hacking don't get into trouble okay so i had a show option here and you can see that that's what the spanning tree message looks like after i manipulated it now what i will do here is run wireshark on windows so that you can see the original messages and the forged messages so what i'll do is capture spanning tree so we can see as an example that at this point the root switch has this root identifier path cost is that type show spanning tree now notice priority is 32769 because we're adding the root identifier or root priority plus the vlan number to give us that that is the root bridge mac address but again i could simply change that in this example i'm sending one packet into the network so one packet has been sent shows spanning tree notice root has changed and if i look at wireshark you can see that here i forged the source mac address so mac address was forged i forged the root identifier and bridge identifier i basically manipulated the frame that i received off the network i received a frame changed some values and sent it back into the network to make myself the spanning tree root now in this example i'm not using a loop but i could simply use a loop here to send multiple frames into the network so i could do something like that what i'll do is add a sleep timer and i'm simply copying some code from another script this is the thing about code don't reinvent it just reuse code so what i'll do is ls nano stp root hack and what i'll do is paste that code in here and i'll remove that line so what this will do now i'll clear the screen is send bpdus into the network every second to make sure that i remain the root so on the switch show spanning tree notice the route is my kali virtual machine and the root port is pointing to cali now what you could do is send some bpd's wait a bit of time like 30 seconds so that it goes back to the original route and send some more bpds and that can really mess up networks you don't want this to happen so what we should be doing on any port that we don't trust we should type spanning tree and we have a few options here but i'll do god root and what should happen is notice root card is enabled it should protect us from these bpd's so if i type show spanning tree spanning tree election has gone back to the proper switch if i run the script what will happen is root guard will block those bpdus so if i type show spanning tree again notice the port has been blocked we are still using the proper root switch or root bridge in our topology spanning tree's been around for many years so we talk about a bridge rather than a switch so the root bridge is still the 2960 in my topology rather than cali we have stopped this nonsense you could also filter bpdus or do other things to protect your network now in ccna courses they often tell you about this but i want you to see how easy it is to use python to hack networks a few lines of code here and you could break a network okay so hopefully you learned something i've shown you now how to use a simple python script to hack networks you need to enable security on your networks but you should learn python because it gives you a lot of power now once again if you enjoyed this video please like it please subscribe to my youtube channel and click on the bell to get notifications i'm david bomble want to wish you all the very best [Music] oh