Lecture Notes: Denial-of-Service (DoS) Attacks What is a Denial-of-Service (DoS) Attack? A DoS attack is a type of cyberattack that aims to disrupt the normal operation of a computer system, network, or other resource by overwhelming it with excessive traffic or requests. This can render the target system unavailable to legitimate users. Types of DoS Attacks ● Volume-based attacks: Overwhelm the target with excessive traffic, such as flooding it with packets. ● Resource-exhaustion attacks: Consume the target's resources, such as CPU, memory, or network bandwidth. ● Application-layer attacks: Exploit vulnerabilities in specific applications or protocols. Common DoS Attack Techniques ● SYN flood: Sends a large number of SYN packets without completing the TCP handshake, consuming server resources. ● Ping flood: Sends a large number of ICMP echo requests to overwhelm the target. ● Distributed Denial-of-Service (DDoS) Attack: Utilizes multiple compromised systems (bots) to launch attacks simultaneously. ● HTTP flood: Sends a large number of HTTP requests to a web server, overwhelming its resources. Impact of DoS Attacks ● Disruption of Services: DoS attacks can render systems and networks unavailable, causing significant disruptions to businesses and organizations. ● Financial Loss: Downtime caused by DoS attacks can result in lost revenue and productivity. ● Damage to Reputation: Frequent DoS attacks can damage an organization's reputation and erode customer trust. Prevention and Mitigation Techniques ● Network Security: Implement robust network security measures, such as firewalls, intrusion detection systems (IDS), and intrusion prevention systems (IPS). ● Traffic Filtering: Use traffic filtering techniques to block malicious traffic. ● Rate Limiting: Limit the number of requests that can be processed per unit of time. ● Distributed Denial-of-Service Mitigation (DDoS Mitigation): Utilize specialized services to protect against large-scale DDoS attacks. ● Backup and Recovery: Implement disaster recovery plans to minimize the impact of DoS attacks. Conclusion DoS attacks pose a significant threat to the security and availability of computer systems and networks. Understanding the various types of DoS attacks and implementing effective prevention and mitigation techniques is crucial for protecting against these threats.