2.2.4 Configure system security parameters to prevent misuse

2.2.4.a Interview system administrators and/or security managers to verify that they have knowledge of common security parameter settings for system components.
2.2.4.b Examine the system configuration standards to verify that common security parameter settings are included.
2.2.4.c Select a sample of system components and inspect the common security parameters to verify that they are set appropriately and in accordance with the configuration standards.

Unnecessary functions can provide additional opportunities for malicious individuals to gain access to a system. By removing unnecessary functionality, organizations can focus on securing the functions that are required and reduce the risk that unknown functions will be exploited.
Including this in server-hardening standards and processes addresses the specific security implications associated with unnecessary functions (for example, by removing/disabling FTP or the web server if the server will not be performing those functions).