Definition
A man-in-the-middle attack, also known as an on-path attack, is a type of cyberattack where an attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other. The attacker intercepts traffic by positioning themselves between the user and the application or service they are trying to access. This allows the attacker to eavesdrop on conversations, steal sensitive information like login credentials or financial data, or even inject malicious content into the communication stream. For instance, an attacker might set up a rogue Wi-Fi hotspot in a public place to intercept traffic from unsuspecting users. This differs from a denial-of-service attack, which aims to disrupt service availability rather than steal data. Understanding man-in-the-middle attacks is crucial for cybersecurity professionals and is frequently tested on exams like CompTIA Security+ and CISSP.