Man-in-the-Middle Attack — Technology Wiki

Overview

Direct Answer

A Man-in-the-Middle (MitM) attack occurs when an attacker intercepts and potentially modifies communications between two parties without their knowledge, positioning themselves as an intermediary in the conversation flow. The attacker can eavesdrop, alter messages, or inject malicious content whilst both parties believe they are communicating directly.

How It Works

The attacker exploits network vulnerabilities or authentication weaknesses to establish themselves between the client and server, typically through ARP spoofing, DNS hijacking, or SSL/TLS downgrade attacks. Once positioned, the attacker forwards traffic between parties whilst capturing or manipulating data in transit, often establishing separate encrypted connections with each party to avoid detection.

Why It Matters

Organisations face substantial compliance and operational risks from these attacks, particularly in financial transactions, healthcare data exchange, and credential theft scenarios. Regulatory frameworks including GDPR and PCI DSS mandate protection against interception attacks, whilst compromised communications can result in fraud, intellectual property loss, and reputational damage.

Common Applications

Such attacks commonly target unencrypted wireless networks in public spaces, corporate VPNs with weak authentication protocols, and banking platforms using legacy encryption. Payment processing systems, email communications, and remote access tools remain frequent targets across financial services, healthcare, and government sectors.

Key Considerations

Modern TLS implementations and certificate pinning significantly mitigate MitM risks, though user behaviour, outdated software, and misconfigured security tools remain exploitable vectors. Perfect forward secrecy and mutual authentication provide defence-in-depth, but organisations must balance security controls with operational complexity.

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