Man-in-the-Middle (MiTM) attacks

Introduction

Man-in-the-Middle (MiTM) attacks are a type of cyber attack where the attacker is able to intercept, alter, and relay traffic between two parties without either party knowing. This type of attack is especially dangerous because it can remain undetected for long periods of time, allowing the attacker to gain access to sensitive information. In this article, we will discuss the various types of MiTM attacks, such as ARP poisoning and TLS MiTM attacks, as well as the tools and techniques used to carry out these attacks. We will also provide example Python code depicting a MiTM attack and recommendations for preventing such attacks.

ARP Poisoning

ARP poisoning is a type of MiTM attack that works by poisoning the Address Resolution Protocol (ARP) cache of a target machine. ARP is a protocol used by computers to map IP addresses to physical hardware addresses, such as the MAC address of a network card. By poisoning the ARP cache, the attacker can redirect traffic from the target machine to their own machine, allowing them to intercept and alter the traffic.

To carry out an ARP poisoning attack, the attacker first needs to determine the IP address of the target machine. This can be done by using a network scanning tool such as Nmap. Once the IP address has been identified, the attacker can then use a tool such as Ettercap to poison the ARP cache of the target machine. Ettercap works by sending a large number of ARP request and response packets to the target machine, causing the ARP cache to be flooded with incorrect information. This incorrect information will cause the target machine to send traffic to the attacker's machine instead of its intended destination.

TLS MiTM Attacks

TLS MiTM attacks are a type of MiTM attack that works by exploiting vulnerabilities in the Transport Layer Security (TLS) protocol. TLS is a protocol used to secure communication between two parties. However, if the protocol is not properly implemented or configured, it can be vulnerable to MiTM attacks.

To carry out a TLS MiTM attack, the attacker first needs to identify a vulnerable TLS connection. This can be done by using a tool such as SSLstrip, which works by monitoring network traffic and identifying TLS connections that are vulnerable to MiTM attacks. Once the vulnerable connection has been identified, the attacker can then use a tool such as SSLsplit to intercept and alter the traffic. SSLsplit works by creating a fake TLS connection between the attacker and the target, allowing the attacker to intercept and alter the traffic before it is sent to the intended destination.

Tools and Techniques

There are a variety of tools and techniques that can be used to carry out MiTM attacks. The most popular tools are Ettercap for ARP poisoning attacks and SSLsplit for TLS MiTM attacks. Other tools such as Wireshark, Nmap, and SSLstrip can also be used to identify vulnerable connections and monitor network traffic.

Example Python Code

The following example Python code can be used to carry out a MiTM attack using ARP poisoning. The code uses the scapy library to send a large number of ARP request and response packets to the target machine, causing the ARP cache to be flooded with incorrect information. This incorrect information will cause the target machine to send traffic to the attacker's machine instead of its intended destination.

from scapy.all import *

target_ip = "192.168.1.1"
attacker_ip = "192.168.1.2"

while True:
    send(ARP(op=2, pdst=target_ip, psrc=attacker_ip))

Prevention

There are a number of steps that can be taken to prevent MiTM attacks. The most important step is to ensure that all TLS connections are properly implemented and configured. This can be done by using a tool such as SSLscan to identify any vulnerabilities in the TLS configuration. Additionally, network administrators should ensure that their network is properly segmented and monitored for suspicious traffic. Finally, users should be aware of the risks associated with MiTM attacks and should take steps to protect their data, such as using a VPN.