Three network security factors are vulnerability, threat, and attack.

Vulnerability is the degree of weakness which is inherent in every network and device. This includes routers, switches, desktops, servers, and even security devices.

Threats include the people interested and qualified in taking advantage of each security weakness. Such individuals can be expected to continually search for new exploits and weaknesses.

Threats are realized by a variety of tools, scripts, and programs to launch attacks against networks and network devices. Typically, the network devices under attack are the endpoints, such as servers and desktop computers.

There are three primary vulnerabilities or weaknesses:

All three of these vulnerabilities or weaknesses can lead to various attacks, including malicious code attacks and network attacks.