Man-in-the-middle attack (MITM)

A man-in-the-middle (MITM) attack is a type of cyberattack where an attacker intercepts and alters the communication between two parties, without either party being aware of the interception. The attacker acts as a middleman between the two parties, intercepting and modifying the communication as needed.

MITM attacks can occur in a variety of contexts, including network-level attacks, where the attacker intercepts network traffic, and application-level attacks, where the attacker intercepts communication between an application and a server.

The key dangers of MITM attacks include theft of sensitive information, unauthorized access to systems and data, and the injection of malicious code or content into the intercepted communication. By intercepting and modifying communication, an attacker can steal sensitive information, such as passwords and financial data, or inject malicious code into the communication, allowing them to gain unauthorized access to systems and data.

Here are some ways to defend against MITM attacks:

1. Encryption: Encrypting the communication channel using protocols such as SSL/TLS helps prevent MITM attacks by ensuring that the data being transmitted cannot be intercepted and read.

2. Certificate Pinning: Certificate pinning allows an application to validate the identity of a server by checking the server's SSL certificate against a pre-defined list of trusted certificates. This helps prevent MITM attacks where the attacker presents a fake certificate.

3. Virtual Private Networks (VPNs): VPNs encrypt all internet traffic and routing it through a secure tunnel, which makes it more difficult for an attacker to intercept and modify the communication. However, if the VPN host becomes compromised, the host itself can open your network up to MITM attacks.

4. Public Key Infrastructure (PKI): PKI is a system that uses digital certificates and public-private key pairs to securely authenticate and encrypt communication. PKI can help prevent MITM attacks by ensuring that the identity of the parties involved in the communication can be validated.

5. User Awareness: Educating users about the dangers of MITM attacks and how to recognize them can help prevent successful attacks. This may include warning users about fake Wi-Fi hotspots, unexpected pop-up messages, and unexpected changes in SSL certificates.

Keep in mind that some 3rd party hosted services are naturally MITM attack vectors. This is why it's sometimes preferable to host your own infrastructure.