Disable Network File Systems (netfs)

An XCCDF Rule

Description

The netfs script manages the boot-time mounting of several types of networked filesystems, of which NFS and Samba are the most common. If these filesystem types are not in use, the script can be disabled, protecting the system somewhat against accidental or malicious changes to /etc/fstab and against flaws in the netfs script itself. The netfs service can be disabled with the following command:

$ sudo systemctl mask --now netfs.service

ID: xccdf_org.ssgproject.content_rule_service_netfs_disabled
Severity: Unknown
Updated: about 1 year ago


[customizations.services]
disabled = ["netfs"]

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" stop 'netfs.service'
"$SYSTEMCTL_EXEC" disable 'netfs.service'"$SYSTEMCTL_EXEC" mask 'netfs.service'
# Disable socket activation if we have a unit file for it
if "$SYSTEMCTL_EXEC" -q list-unit-files netfs.socket; then
    "$SYSTEMCTL_EXEC" stop 'netfs.socket'
    "$SYSTEMCTL_EXEC" mask 'netfs.socket'
fi
# The service may not be running because it has been started and failed,
# so let's reset the state so OVAL checks pass.
# Service should be 'inactive', not 'failed' after reboot though.
"$SYSTEMCTL_EXEC" reset-failed 'netfs.service' || true

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

include disable_netfs

class disable_netfs {
  service {'netfs':
    enable => false,
    ensure => 'stopped',  }
}

- name: Block Disable service netfs
  block:

  - name: Disable service netfs
    block:
    - name: Disable service netfs
      systemd:
        name: netfs.service
        enabled: 'no'
        state: stopped
        masked: 'yes'
    rescue:

    - name: Intentionally ignored previous 'Disable service netfs' failure, service
        was already disabled
      meta: noop
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_netfs_disabled
  - unknown_severity

- name: Unit Socket Exists - netfs.socket
  command: systemctl -q list-unit-files netfs.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_netfs_disabled
  - unknown_severity

- name: Disable socket netfs
  systemd:
    name: netfs.socket
    enabled: 'no'
    state: stopped
    masked: 'yes'
  when:
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - socket_file_exists.stdout_lines is search("netfs.socket",multiline=True)
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_netfs_disabled
  - unknown_severity

Disable Network File Systems (netfs)

Description

Remediation - OS Build Blueprint

Remediation - Shell Script

Remediation - Puppet

Remediation - Ansible