Yersinia

Yersinia is a network security framework written in C that specializes in attacking layer-2 network protocols, targeting the foundational switching and routing mechanisms that most security tools overlook. It supports attacks against Spanning Tree Protocol (STP), Cisco Discovery Protocol (CDP), Dynamic Trunking Protocol (DTP), DHCP, 802.1Q VLAN tagging, Hot Standby Router Protocol (HSRP), and other layer-2 protocols. Network penetration testers and red team operators use Yersinia to demonstrate the devastating impact of layer-2 attacks, which can result in network-wide denial of service, traffic interception, VLAN hopping, and man-in-the-middle positioning. The tool provides both a command-line and ncurses-based interactive interface, making it the definitive framework for assessing an organization's resilience against infrastructure-level network attacks.