The Greenbone Operating System (GOS) is the operating system of the Greenbone Enterprise Appliance that is part of the commercial Greenbone Enterprise product line. Here is an architecture overview for GOS 22.04.
Greenbone Operating System (GOS)
The GOS control layer provides access to the administration of the Greenbone Operating System (GOS). Only a single system administrator account is supported. The system administrator cannot modify system files directly but can instruct the system to change configurations.
GOS is managed using a menu-based graphical interface (GOS administration menu). The system administrator is not required to use the command line (shell) for configuration or maintenance tasks. Shell access is provided for support and troubleshooting purposes only.
Accessing the system level requires either console access (serial, hypervisor or monitor/keyboard) or a connection via SSH.
GOS allows users to configure, start, and stop all services of the Greenbone Community Edition.
Greenbone Community Edition
The Greenbone Community Edition consists of a framework with several services. It is developed as part of the Greenbone Enterprise products.
The Greenbone Community Edition was originally built as a community project named “OpenVAS” and is primarily developed and forwarded by Greenbone Networks. It consists of the Greenbone Vulnerability Manager Daemon (gvmd), the Greenbone Security Assistant (GSA) with the Greenbone Security Assistant Daemon (gsad) and the executable scan application that runs vulnerability tests (VT) against target systems.
The Greenbone Community Edition is released under open-source licenses. By using it, Linux distributions can create and provide the software components in the form of installation packages.
Greenbone Vulnerability Manager Daemon (gvmd)
The Greenbone Vulnerability Manager (gvmd) is the central service that consolidates plain vulnerability scanning into a full vulnerability management solution. gvmd controls the OpenVAS Scanner via Open Scanner Protocol (OSP). It is XML-based, stateless and does not require a permanent connection for communication.
The service itself offers the XML-based, stateless Greenbone Management Protocol (GMP). gvmd also controls an SQL database (PostgreSQL) where all configuration and scan result data is centrally stored. Furthermore, gvmd also handles user management including permissions control with groups and roles. And finally, the service has an internal runtime system for scheduled tasks and other events.
Greenbone Security Assistant (GSA)
The Greenbone Security Assistant (GSA) is the web interface that a user controls scans and accesses vulnerability information with. It is the main contact point for a user with the appliance. It connects to gvmd via the web server Greenbone Security Assistant Daemon (gsad) to provide a full-featured web application for vulnerability management. The communication occurs using the Greenbone Management Protocol (GMP) with which the user can also communicate directly by using different tools.
The main scanner OpenVAS Scanner is a full-featured scan engine that executes vulnerability tests (VTs) against target systems. For this, it uses the daily updated and comprehensive feeds: the full-featured, extensive, commercial Greenbone Enterprise Feed or the free available Greenbone Community Feed.
The scanner consists of the components ospd-openvas and openvas-scanner. The OpenVAS Scanner is controlled via OSP. The OSP Daemon for the OpenVAS Scanner (ospd-openvas) communicates with gvmd via OSP: VT data is collected, scans are started and stopped, and scan results are transferred to gvmd via ospd.
The Notus scanner scans after every regular scan, so no user interaction is necessary. It offers better performance due to less system resource consumption and thus, faster scanning.
The Notus scanner replaces the logic of potentially all NASL-based local security checks (LSCs). A comparison of installed software on a host against a list of known vulnerable software is done instead of running a VT script for each LSC.
The regular OpenVAS Scanner loads each NASL LSC individually and executes it one by one for every host. A single known vulnerability is then compared with the installed software. This is repeated for all LSCs.
With the Notus scanner, the list of installed software is loaded in the same way, but is directly compared with all known vulnerable software for the operating system of the scanned host. This eliminates the need to run the LSCs because the information about the known vulnerable software is collected in one single list and not distributed in individual NASL scripts.
The Greenbone Vulnerability Management Tools (gvm-tools) are a collection of tools that help with remote controlling a Greenbone Enterprise Appliance and its underlying Greenbone Vulnerability Manager Daemon (gvmd). The tools aid in accessing the communication protocols GMP (Greenbone Management Protocol) and OSP (Open Scanner Protocol).
This module is comprised of interactive and non-interactive clients. The programming language Python is supported directly for interactive scripting. But it is also possible to issue remote GMP/OSP commands without programming in Python.