Yersinia is a low-level protocol attack tool useful for penetration testing. It is capable of many diverse attacks over multiple protocols, such as becoming the root role in the Spanning Tree (Spanning Tree Protocol), creating virtual CDP (Cisco Discovery Protocol) neighbors, becoming the active router in a HSRP (Hot Standby Router Protocol) scenario, faking DHCP replies, and other low-level attacks. For downloads and more information, visit the Yersinia homepage.

#59, 7
Latest release
  • 0.7.1
  • Jan. 26, 2007 (17 years, 3 months ago)
★★★★★ (2)
100% ★★★★
0% ★★★
0% ★★



no rating arinc9

10 years after TeasyPea's comment, they have really inspired me to look further into this while I'm working my way to get CCNA certified. Huge respect!

★★★★★ Blastman

IMHO the best (perhaps the only) tool for crafting layer 2 packets and/or sending network attacks, although the daemon mode is very interesting the ncurses mode(yersinia -I) became more useful for learning how your network works and reacts to certain attacks.

They (the authors) released recently a new version 0.7.3 that fixes some important bugs, btw, the source code repository was moved to Github at

★★★★★ TeasyPea

Yersinia is an excellent tool for those interested in understanding/controlling the lower layers of the network (Physical, Datalink, Network).

I fell in love with this tool thanks to to the highly informative & entertaining talk given by the Figueroa brothers at DEFCON 16.

ChRiStIaAn008 has kindly made the video of their talk available on his youtube channel.

Yersinia is an essential part of my low-level stack arsenal, along with dsniff, ettercap, netcat, etc.

It has been a great tool for helping understand protocols such as: VTP, ISL, HSRP, DHCP, DTP, CDP & STP.

For those intimidated by the command line, you may use Yersinia's (GTK) Graphical User Interface by using the argument: :~# yersinia -G

One of my favorite functions of Yersinia is the Daemon Mode: :~# yersinia -D The Daemon mode allows you to start a network listener for remote administration. Because it uses Cisco CLI emulation while in Daemon mode, it becomes not only a powerful networking tool, but an excellent way to fine tune your cisco networking skills. I hope that i given this a fair review & inspired someone to give Yersinia a try. If you are fascinated with the lower network layers, with Cisco routers, or simply wish to become the supreme network overlord through Yersinia's many capable potent attacks, I recommend that you give this unique tool a try today!

Don't forget to check out video featuring the brothers who created yersinia. It is titled: Defcon 16 "VLANs Layer 2 Attacks: Their Relevance and their Kryptonite" available on youtube. If you find Yersinia useful, give these guys a hollar and let them know your thoughts.

Thank you for your time.


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