Askeal Logo

Man-in-the-middle

A Man-in-the-Middle (MITM) attack occurs when an attacker secretly intercepts, relays, or alters communications between two parties who believe they are communicating directly.

What is a MITM attack?

A MITM attack places an adversary “in the path” of communication so the attacker can eavesdrop, steal credentials or modify messages without the communicating parties noticing. It can target network traffic (e.g., ARP spoofing on a local network), email transmission, web traffic (HTTPS interception), or authentication flows.

How it typically works?


  1. Interception: the attacker gains the ability to see messages between two endpoints (e.g., by controlling a Wi-Fi access point or using ARP/DNS spoofing).
  2. Relaying / impersonation: the attacker forwards messages while masquerading as one or both parties.
  3. Exfiltration or manipulation: credentials or data are stolen, or messages are altered (e.g., payment details replaced).
    These basic steps apply across different MITM techniques.

Common techniques & variants


  • ARP poisoning / local network spoofing (classic local-LAN MITM).
  • HTTPS interception / TLS downgrade or forged certificates (active interception of web traffic).
  • DNS spoofing / pharming (redirecting traffic to attacker-controlled hosts).
  • Proxying and AITM (Adversary-in-the-Middle) phishing (malicious sites that proxy real sites to capture credentials).

Impact


MITM attacks can result in credential theft, session hijacking, fraudulent transactions, data leakage, or injection of malware. Even short-lived interception can expose highly sensitive data (tokens, OTPs, personal information).

Further reading


  • NIST: Man-in-the-Middle Attack. Read more
  • OWASP: Manipulator-in-the-middle attack (attack description & mitigations). Read more
  • CISA: Mobile Communications Best Practice Guidance (secure end-to-end communications) [PDF / guidance page]. Read more
  • Rapid7: Man-in-the-Middle attacks: detection & analysis (overview + detection guidance). Read more
  • Fortinet: Man-in-the-Middle Attack: types & examples. Read more