What does the term “attack surface” refer to in information security?

In information security, the term "attack surface" specifically refers to the exposed parts of a system that are vulnerable to attack. This includes any points where an unauthorized user could try to enter data or extract data from an environment. Each entry point, such as software interfaces, network services, and even physical access points, forms part of this attack surface. By identifying and analyzing the attack surface, security professionals can better understand where vulnerabilities may exist and focus their defenses more effectively to mitigate potential threats.

By contrast, the total number of vulnerabilities available describes a broader concept that includes known vulnerabilities in the system but doesn’t specifically relate to the exposed interfaces. The physical locations of network devices concern hardware setup and placement, which is important but does not directly correlate with the concept of attack exposure. Lastly, while security protocols play a critical role in protecting systems, they do not define an attack surface; rather, they are mechanisms intended to safeguard the areas of the attack surface.