Implementing an air gap for the legacy systems is the best solution to improve their security posture. An air gap is a physical separation of a system or network from any other system or network that may pose a threat. An air gap can prevent any unauthorized access or data transfer between the isolated system or network and the external environment. Implementing an air gap for the legacy systems can help to protect them from being exploited by attackers who may take advantage of their unpatched vulnerabilities .