DDoS attacks occurs when compromised devices flood the network traffic of a targeted system. This type of attack threatens the availability of the system. When it comes to DDoS attacks, there are four attack vectors:
- Volumetric attack: This floods the victim using the organization's bandwidth.
- Fragmentation attacks: This attack exploits datagram fragmentation mechanisms by preventing the reassembling back of fragmented data packets. It is also called Teardrop attack.
- TCP state-exhaustion attack: This attack exhaust the number of concurrent connections supported by web servers, load balancers and firewalls.
- Application layer attack: This uses application weaknesses to disable the service. As shown in the following graph, an attacker exploits compromised hosts also known as zombies to perform a DDoS attack against his target.