Introduction

Overview

Teaching: 10 min
Exercises: 0 min

Questions

• What is network security?

• What are some types of network security attacks?

• What are the broader impacts of network security issues?

Objectives

• Describe man-in-the-middle attacks

• Describe various vulnerabilities in computer networks

Network Security

Network security is primarily concerned with unauthorized access, denial, or, malicious modification of network communication. Network security attacks can involve passive exploits such as eavsdropping or wiretapping, where a hacker can monitor all communication on a network and access privileged information. Other attacks such as a man-in-the-middle attack involve a hacker inserting themselves in between two communicating parties and intercepting and possibly altering the communication between them without their knowledge. With the centrality of computers and network communication in activities such as banking, commerce, social media, and communication to name a few; the ability to intercept and alter network traffic can have far-reaching consequences. Hackers can intercept authentication information, privileged information such as credit card and social security data, and use this information for nefarious purposes.

Man-in-the-middle Attack

In a man-in-the-middle (MITM) attack, a hacker has successfully intercepted communication between two parties, without their knowledge. Each of the affected parties assumes they are directly communicating with their intended counterpart, but are instead communicating with the hacker who is relaying possibly modified traffic between the parties. With the ability to modify communication, a hacker can insert malicious links and code into web content being transmitted from a server to a client, turn off SSL communication by transforming HTTPS links into HTTP, and more.

In the next lesson, we will learn about a particular MITM attack, ARP Poisoning.

Key Points

• Network security affects all modern communication!