What is a common characteristic of Denial of Service (DoS) attacks?

A fundamental characteristic of Denial of Service (DoS) attacks is their intent to make a service unavailable to legitimate users. This is achieved by overwhelming the target system, server, or network with a flood of traffic or by exploiting specific vulnerabilities that hinder normal service operations. The ultimate goal is to disrupt the normal functioning of the service, preventing users from accessing it, thus denying them a service that is usually available.

While IP spoofing can be part of some sophisticated DoS attacks, it is not a defining feature of all such attacks. Similarly, although some DoS attacks could take advantage of authentication weaknesses, this is not a commonality among all. Additionally, requiring physical access to a device is not a characteristic of DoS attacks, as these attacks are predominantly conducted remotely over the internet. Hence, focusing on the primary aim of a DoS attack clarifies why making a service unavailable to legitimate users is the key feature being emphasized.