Nessus

Nessus is a vulnerability scanner developed by Tenable Network Security to identify security vulnerabilities in systems and applications. It performs in-depth assessments of the system's configuration, software, and other elements. Nessus is used by many IT professionals and is often considered the de-facto industry standard for vulnerability assessment. These users range from system administrators, penetration testers, and compliance auditors, who all use Nessus to identify any potential vulnerabilities in a system.

Nessus can perform a range of different scan types and can scan for vulnerabilities in various systems, including Windows, Linux, and other *NIX systems. Nessus also supports the scanning of network devices such as routers and switches, as well as the scanning of web applications. The free version of Nessus – Nessus Essentials – provides more than 20 different scan templates to the user. Scans ranging from simple host discovery to the identification of specific vulnerabilities can be performed using Nessus