A newly installed operating system is inherently insecure. It presents certain vulnerabilities based on factors such as the age of the OS, the presence of backdoors, the services it provides, and the use of default policies that do not prioritize security. When we refer to the fortification of an operating system, we mean the act of configuring this OS with the intention of making it as secure as possible, aiming to minimize the risk of it being compromised and exploited by any vulnerabilities. This typically involves applying security patches, changing certain default OS policies, and removing (or deactivating) non-essential applications and services.
The document of the teaching guide can be consulted at the UDC link specified above.
