Person‐in‐the‐Middle (PitM) - secuguru/security-terms GitHub Wiki

Person-in-the-Middle (PitM), also known as. Man-in-the-Middle (MitM), is a type of cyberattack where an attacker secretly intercepts and potentially alters communication between two parties who believe they are directly communicating with each other. In a PitM attack, the attacker is positioned between the sender and receiver and can intercept, modify, or manipulate the data being exchanged without either party realizing it.

How PitM Attacks Work

  1. Intercepting Communication:
  • The attacker intercepts the communication channel between two parties (e.g., client and server, or two individuals). This can be achieved in various ways, such as:
    • Wi-Fi eavesdropping: Intercepting traffic on an unencrypted or poorly secured Wi-Fi network.
    • DNS spoofing: Redirecting a victim’s DNS queries to malicious IP addresses.
    • ARP spoofing: Sending fake Address Resolution Protocol (ARP) messages to link the attacker’s MAC address with a legitimate IP address on a local network.
  1. Relaying or Modifying Data:
  • Once in the middle of the communication, the attacker can either passively eavesdrop on the data being exchanged or actively alter it. For instance:
    • Eavesdropping: The attacker silently monitors the data, gaining access to sensitive information like passwords, personal messages, or banking information.
    • Modifying Data: The attacker can modify the contents of messages, transactions, or other communications, leading to fraud or miscommunication between the parties.
  1. Impersonation:
  • In some cases, the attacker impersonates one of the parties in the communication. For example, in an HTTPS MitM attack, the attacker may present a fake certificate to make the victim believe they are securely communicating with the real website, while all data is routed through the attacker’s server.

Types of PitM Attacks

  1. Wi-Fi Eavesdropping:
  • Attackers can intercept unencrypted traffic over unsecured public Wi-Fi networks. Victims connected to the same network can have their communications intercepted, including login credentials and sensitive data.
  1. SSL Stripping:
  • This attack downgrades a secure HTTPS connection to an unencrypted HTTP connection. The attacker intercepts the victim’s request for an HTTPS website and responds with an HTTP version, allowing the attacker to capture sensitive data, like login credentials, in plaintext.
  1. DNS Spoofing:
  • The attacker manipulates DNS queries to redirect victims to malicious websites without their knowledge. For example, when a user tries to access a legitimate site, the attacker sends a false IP address, leading the victim to a fake site controlled by the attacker.
  1. ARP Spoofing:
  • In local network environments, attackers can send forged ARP messages to associate their MAC address with the IP address of another device (e.g., a router or server). This allows them to intercept traffic intended for the legitimate device.
  1. Session Hijacking:
  • The attacker intercepts session tokens (used to maintain authenticated sessions between a client and a server) and uses them to impersonate the victim, effectively taking over their session.
  1. Email Hijacking:
  • Attackers gain access to email communications between parties, such as during financial transactions. The attacker can modify invoice details or payment instructions to divert funds to their own account.

Impacts of PitM Attacks

  • Data Theft: Attackers can steal sensitive information, such as login credentials, credit card numbers, or personal messages.
  • Financial Fraud: PitM attacks can result in the interception or redirection of financial transactions, leading to fraud and theft.
  • Unauthorized Access: The attacker can gain unauthorized access to accounts or systems by intercepting and using credentials or session tokens.
  • Reputation Damage: PitM attacks can compromise trust between communicating parties, particularly if sensitive business or financial data is involved.

Prevention of PitM Attacks

  1. Encryption:
  • Use strong encryption protocols (such as HTTPS and SSL/TLS) to secure communication channels and ensure that data transmitted between parties is encrypted, preventing interception.
  • Avoid using public Wi-Fi networks for sensitive transactions unless the connection is protected by a VPN (Virtual Private Network).
  1. Authentication:
  • Implement multi-factor authentication (MFA) to add an extra layer of security. Even if an attacker intercepts login credentials, they will not be able to access the account without the second factor.
  • Ensure the use of trusted certificates when communicating over HTTPS, and be cautious of certificate warnings from your browser.
  1. DNS Security:
  • Use DNSSEC (Domain Name System Security Extensions) to ensure the integrity of DNS responses and prevent DNS spoofing attacks.
  1. Network Security:
  • Use strong encryption for Wi-Fi networks (e.g., WPA3) and monitor for ARP spoofing using security tools that detect and block ARP poisoning attempts.
  • Implement firewalls and intrusion detection systems (IDS) to monitor traffic for suspicious behavior or patterns indicative of PitM attacks.
  1. User Vigilance:
  • Educate users to avoid clicking on suspicious links or accessing sensitive accounts on public networks.
  • Regularly verify website certificates and look for “HTTPS” in the URL bar to ensure secure connections.

In summary, Person-in-the-Middle (PitM) attacks involve intercepting and manipulating communications between two parties. These attacks can result in data theft, financial fraud, or unauthorized access to sensitive systems. Encryption, strong authentication methods, and secure network practices are essential defenses against such attacks.