Yersinia is a network tool designed to take advantage of some weakeness in different network protocols. It pretends to be a solid framework for analyzing and testing the deployed networks and systems.

Currently, there are some network protocols implemented, but others are coming (tell us which one is your preferred). Attacks for the following network protocols are implemented (but of course you are free for implementing new ones):

Spanning Tree Protocol (STP)
Cisco Discovery Protocol (CDP)
Dynamic Trunking Protocol (DTP)
Dynamic Host Configuration Protocol (DHCP)
Hot Standby Router Protocol (HSRP)
IEEE 802.1Q
IEEE 802.1X
Inter-Switch Link Protocol (ISL)
VLAN Trunking Protocol (VTP)

Spanning Tree Protocol

Sending RAW Configuration BPDU
Sending RAW TCN BPDU
DoS sending RAW Configuration BPDU
DoS sending RAW TCN BPDU
Claiming Root Role
Claiming Other Role
Claiming Root Role dual home (MITM)

Cisco Discovery Protocol

Sending RAW CDP packet
DoS flooding CDP neighbors table
Setting up a virtual device

Dynamic Host Configuration Protocol

Sending RAW DHCP packet
DoS sending DISCOVER packet (exhausting ip pool)
Setting up rogue DHCP server
DoS sending RELEASE packet (releasing assigned ip)

Hot Standby Router Protocol

Sending RAW HSRP packet
Becoming active router
Becoming active router (MITM)

Dynamic Trunking Protocol

Sending RAW DTP packet
Enabling trunking

802.1Q

Sending RAW 802.1Q packet
Sending double encapsulated 802.1Q packet
Sending 802.1Q ARP Poisoning

802.1X

Sending RAW 802.1X packet
Mitm 802.1X with 2 interfaces

VLAN Trunking Protocol

Sending RAW VTP packet
Deleting ALL VLANs
Deleting selected VLAN
Adding one VLAN
Catalyst crash

Screen Shots:
http://www.yersinia.net/img/gui.png

http://www.yersinia.net/img/networkclient.png