# CIS Ubuntu 14.04 LTS - 3.4.2 Ensure /etc/hosts.allow is configured > Verify that /etc/hosts.allow is configured to permit authorized network access - Skill: `cyberstrikeus/cis-ubuntu-14-04-lts-3-4-2-ensure-etc-hosts-allow-is-configu` (Agent Skill) - Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu-14-04-lts-3-4-2-ensure-etc-hosts-allow-is-configu` - Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu-14-04-lts-3-4-2-ensure-etc-hosts-allow-is-configu/raw - Safety review: PASS (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu-14-04-lts-3-4-2-ensure-etc-hosts-allow-is-configu --- # 3.4.2 Ensure /etc/hosts.allow is configured (Scored) ## Profile Applicability - Level 1 - Server - Level 1 - Workstation ## Description The `/etc/hosts.allow` file specifies which IP addresses are permitted to connect to the host. It is intended to be used in conjunction with the `/etc/hosts.deny` file. ## Rationale The `/etc/hosts.allow` file supports access control by IP and helps ensure that only authorized systems can connect to the system. ## Audit Procedure Run the following command and verify the contents of the `/etc/hosts.allow` file: ```bash cat /etc/hosts.allow ``` ## Expected Result The file should contain appropriate network allow rules for your environment. ## Remediation Run the following command to create `/etc/hosts.allow`: ```bash echo "ALL: /, /, ..." >/etc/hosts.allow ``` where each `/` combination (for example, "192.168.1.0/255.255.255.0") represents one network block in use by your organization that requires access to this system. ## Default Value Contents of `/etc/hosts.allow` file will vary depending on your network configuration. ## References - CIS Controls: 9.2 - Leverage Host-based Firewalls ## Profile - Level 1 - Server - Level 1 - Workstation