CertiK testing Finite State Machines (FSM) for auditing.

CertiK engineers recently applied the use of Finite State Machines (FSM) to auditing and uncovered a critical bug.
 A Finite State Machine (FSM) is a computational model that represents a system's behavior through a finite number of states, transitions between those states, and an initial state. As the complexity of Web3 applications grows, so does the need for robust auditing solutions. FSMs offer a novel framework for scrutinizing smart contracts and protocol states, helping to increase the precision of audits. 
FSMs are most effective when integrated with other audit methodologies like fuzz testing and formal verification, as they mutually strengthen and enhance each other's capabilities. FSMs allow for the integration of security features at the initial design phase. With highly-measurable security attributes, auditors can quantify risks in a way rarely achievable through other means.
As always, FSMs have their limitations. A lack of protocol documentation can hamper their utility. For larger codebases, scalability and computational challenges arise, requiring auditors to break down main flows into sub-flows. A solid foundation of protocol specs and design choices is key for auditors to effectively apply the FSM methodology.
While FSMs are far from a magic bullet, they offer an additional lens through which to examine blockchain security. When used effectively, they can unearth vulnerabilities that might otherwise slip through the cracks. 
The inclusion of FSMs in the auditing arsenal marks a step toward a more secure and robust blockchain environment, forging an evermore comprehensive approach to security.