Denial of service (DoS) attack is a cyberattack that depletes computer systems and network resources, rendering it inaccessible even to authorized or valid users. It accomplishes this by bombarding or flooding the target system with unsolicited traffic or by sending voluminous information that may cause the system to crash or be nonresponsive. And through this technique, it deprives legitimate or valid users from accessing services and system resources that are critical to perform their day to day activities. To aggravate its attack effects, DoS based cyberattacks target web servers of organizations such as government, banking, media corporations, trade and commercial organizations.
DoS attacks manifest its nefarious nature through two methods namely flooding services or crashing those services.
- Flooding Services: Flooding attacks happen when the computer system or network receives too much traffic or request to the extent that the server or the network system cannot entertain or handle. This will cause the resources to slow down and eventually stop providing intended services. The most common types of flooding attacks include buffer overflow attacks, ICMP flooding and SYN flooding attacks.
- Crashing Services: And the other DoS attacks exploit weaknesses or vulnerabilities that may cause the target computer system or network services to crash altogether. This type of attacks takes advantages of vulnerabilities or bugs in the target system and the cybercriminals exploit the vulnerabilities to crash or severely damage the system to be out of services.
Another variant of Denial of service (DoS) attacks is the famous Distributed denial of service (DDoS) attack. In addition, a DDoS attack happens when multiple systems or bots unleash a synchronized and unsolicited DoS attack to a single target system. The difference between DoS and DDoS attacks is that, in DDoS based attacks, instead of attacking the target system from one geographic location, it orchestrates and attacks the target from different locations at once