A CDE Definition

A programmer who legally attempts to break into a computer system or network in order to find its vulnerabilities. See penetration test.

A test of a network's vulnerabilities by having an authorized individual actually attempt to break into the network. The tester may undertake several methods, workarounds and "hacks" to gain entry, often initially getting through to one seemingly harmless section, and from there, attacking more sensitive areas of the network.

Security experts recommend that an annual penetration test be undertaken as a supplement to a more frequent automated security scan. See security scan and ethical hacker.