This document is a client alert that outlines the cyber security risks associated with airport operations, particularly focusing on the vulnerabilities of airport interfaces to potential cyber-attacks. It discusses the findings of an investigation by Pen Test Partners, which identified 17 airport interfaces that are at risk. These interfaces include the airport's Wi-Fi system, crew and flight information systems, building management systems, passenger-assist systems, and runway/taxiway/ramp systems. The alert details specific vulnerabilities, such as outdated security measures in crew access controls and the potential for spoofing signals in airside vehicles and Instrument Landing Systems. The report emphasizes the need for improved security measures and system segregation to mitigate these risks. It highlights the frequency of cyber-attacks on airports and the significant challenges faced in securing these systems while maintaining interoperability among various stakeholders involved in airport operations.