How to apply security Patches on FreeBSD 12.0

Applying security patches in a timely manner and upgrading to a newer release of an operating system are important aspects of ongoing system administration. FreeBSD includes a utility called freebsd-update which can be used to perform both these tasks

FreeBSD security patches may be downloaded and installed using the following commands. The first command will determine if any outstanding patches are available, and if so, will list the files that will be modifed if the patches are applied. The second command will apply the patches

# freebsd-update fetch

# freebsd-update install

If the update applies any kernel patches, the system will need a reboot in order to boot into the patched kernel. If the patch was applied to any running binaries, the affected applications should be restarted so that the patched version of the binary is used.

The system can be configured to automatically check for updates once every day by adding this entry to /etc/crontab:

@daily          root   freebsd-update cron

References:
FreeBsd Handbook