Local and online vulnerability databases

Together, passive and active reconnaissance identify the attack surface of the target, that is, the total number of points that can be assessed for vulnerabilities. A server with just an operating system installed can only be exploited if there are vulnerabilities in that particular operating system; however, the number of potential vulnerabilities increases with each application that is installed.

Penetration testers and attackers must find the particular exploits that will compromise known and suspected vulnerabilities. The first place to start the search is at vendor sites; most hardware and application vendors release vulnerability information when they release patches and upgrades. If an exploit for a particular weakness is known, most vendors will highlight this to their customers.

Although their intent is to allow customers to test for the presence of the vulnerability themselves, attackers and penetration testers will take...