Quick Definition
An attack surface consists of all of the possible attack vectors that exist within a network.
An organization’s security team will try to reduce its attack surface by limiting what portions of the network are exposed to the internet, reducing the number of endpoints on the network to the bare minimum, reducing the number of identities used by uses, limiting the number of administrators capable of changing the network, consolidating valuable resources into segmented partitions, etc. Anything that could provide an initial foothold or avenue towards a high-value resource is an attack surface. Examples include, users, desktop computers, laptops, servers, websites, API endpoints, operating systems, software, physical network access points.
Quick Definition
An attack surface is a conceptual "area" of use and activity where security vulnerabilities may exist, and which therefore becomes a target for cybersecurity attacks.
Common attack surfaces include networks, consoles, login prompts, integration endpoints, support teams and call centers, or any other avenues through which an attacker may plausibly seek vulnerabilities that can be exploited in order to gain illicit access to an organization's systems, data, or resources.
Security-minded organizations common seek to reduce their overall "attack surface area" in order to lower the probability that an attacker will be able to find and exploit a vulnerability in order to achieve such access.
