Denial of Service - CompTIA Security+ SY0-701 - 2.4
Denial of Service Attacks Explained
Understanding Denial of Service (DoS) Attacks
- A denial of service occurs when an attacker intentionally forces a service to fail, often by overloading it or exploiting known vulnerabilities.
- Organizations may also create DoS attacks against competitors as a competitive advantage, effectively removing them from the internet.
- Simple actions, like unplugging power or misconfiguring network switches, can unintentionally cause self-inflicted denial of service situations.
Examples and Consequences of DoS
- Downloading large files on limited bandwidth can lead to denial of service for other applications due to resource exhaustion.
- Physical incidents, such as water damage in data centers, can also result in denial of service scenarios.
Distributed Denial of Service (DDoS)
- Attackers utilize multiple devices globally to execute Distributed Denial of Service (DDoS) attacks, overwhelming web servers with traffic.
- Botnets are networks of infected devices controlled by attackers that can be commanded to launch DDoS attacks efficiently.
Asymmetric Threat Landscape
- DDoS attacks represent an asymmetric threat where attackers use fewer resources to disrupt larger organizations with more systems and bandwidth.
- Attackers amplify their impact by sending small amounts of data that generate large responses from targeted services.
Amplification Techniques in DDoS Attacks
- Reflection and amplification techniques exploit common internet protocols like NTP and DNS to increase attack effectiveness.
- For instance, a DNS query requesting minimal information can return significantly larger responses, amplifying the attack's impact on the victim's server.
Execution Process for DDoS Attacks
- The process involves botnet command and control systems directing infected devices to perform queries on open DNS resolvers for amplification purposes.