Man-in-the-Middle Attack (MITM attack) is a network attack method. The attacker intercepts normal network communication and acts as a middleman to steal, tamper with or manipulate the data of both parties in communication. It is indeed possible to use the defects of network protocols to carry out man-in-the-middle attacks to steal data. The following is a specific explanation: - **Network protocol vulnerabilities**: Many network protocols may have security vulnerabilities in the design and implementation process for various reasons. For example, the early wireless network security protocol WEP (Wired Equivalent Privacy) has serious security flaws and is vulnerable to man-in-the-middle attacks. Attackers can exploit these vulnerabilities and insert themselves into the communication link through deception, disguise, etc., establish connections with both parties, and then carry out attacks. - **Steps for implementing man-in-the-middle attacks** 1. **Detect and establish connection with the target**: The attacker first needs to find the two parties in the target network that are communicating and determine the network protocol and port they are using. For example, in a public Wi-Fi environment, an attacker can monitor network traffic to find that a user is visiting a website and determine the HTTP or HTTPS protocol used by the website. 2. **Disguise and deception**: The attacker disguises himself as one party in the communication and sends forged data packets to the other party, making both parties mistakenly believe that they are communicating directly with each other. For example, the attacker disguises himself as a Wi-Fi access point and sends a false authentication request to the user's device to obtain the user's login credentials. 3. **Data theft and tampering**: Once the connection is established, the attacker can intercept the data transmitted between the two parties and steal or tamper with it. For example, the attacker can steal the account number and password entered by the user when logging in to the online bank, or tamper with key information such as the transaction amount transmitted between the user and the server. 4. **Forwarding data**: In order not to be detected by the communicating parties, the attacker will forward the data to the other party after stealing or tampering with the data, so that the communication still appears to be normal. To prevent man-in-the-middle attacks, users can take some measures, such as using secure network protocols (such as HTTPS), avoiding the transmission of sensitive information on insecure public networks, and installing firewalls and antivirus software. At the same time, network administrators should also update the firmware and software of network devices in a timely manner, fix known security vulnerabilities, and strengthen network security protection.