The Greenbone Operating System (GOS) is the operating system of the commercial product line Greenbone Enterprise Appliance. Here is an architecture overview for GOS 20.08 and GOS 21.04.
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 Vulnerability Management (GVM) framework.
Greenbone Vulnerability Management (GVM)
The Greenbone Vulnerability Management (GVM) is a framework 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 GVM framework is released under open-source licenses as the Greenbone Community Edition. By using it, Linux distributions can create and provide GVM 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).
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 of GVM that a user controls scans and accesses vulnerability information with. It the main contact point for a user with GVM. 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 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.
Users can develop and connect their own OSP scanners using the generic ospd scanner framework. An (generic) OSP scanner example which can be used as an OSP scanner template can be found here.
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.