Man-in-the-middle (MITM) attacks allow the adversary to intercept traffic to and/or from a particular device on the network. MITM attacks may allow an adversary to perform the following attacks: block, log, modify, or inject traffic into the communication stream. Mitigations can be used to protect against MITM, authentication mechanisms should not send credentials across the network in plaintext and should also implement mechanisms to prevent replay attacks (such as nonces or timestamps)”]
Source: https://collaborate.mitre.org/attackics/index.php/Technique/T0830