GLOSSARY / Man-in-the-Middle (MITM)
What is Man-in-the-Middle (MITM)?
An attack where the adversary secretly relays and possibly alters communication between two parties.
By positioning between client and server — via ARP spoofing, rogue Wi-Fi, or DNS tampering — an attacker can read or modify traffic. Unencrypted or improperly validated TLS connections are the prime targets.
Certificate validation and HSTS make MITM far harder on the modern web.
How to defend
Enforce TLS everywhere with valid certificates, enable HSTS, and avoid untrusted networks without a VPN.
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Part of the Ciphers Security glossary. Free reference for analysts, defenders & learners.