Man-in-the-Middle Attack

A man-in-the-middle attack, also called a MITM or on-path attack, places an attacker between communicating parties. The attacker intercepts, relays, or changes communication while the parties may believe they communicate directly. DNS hijacking can redirect a connection toward the attacker. HTTPS normally counters endpoint impersonation through certificate validation and proof of private-key possession. A compromised certificate authority can undermine that authentication when a client still accepts the affected authority. Encryption can then protect a connection whose endpoint is the attacker.