CIS Ubuntu 14.04 LTS - 3.4.3 Ensure /etc/hosts.deny is configured

DevOps & Security

Verify that /etc/hosts.deny is configured to deny all unauthorized network access

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Operating_Systems/Ubuntu/CIS_Ubuntu_Linux_14.04_LTS_Benchmark_v2.1.0/cis-ubuntu1404-v210-3-4-3/SKILL.md

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3.4.3 Ensure /etc/hosts.deny is configured (Scored)

Profile Applicability

Level 1 - Server
Level 1 - Workstation

Description

The /etc/hosts.deny file specifies which IP addresses are not permitted to connect to the host. It is intended to be used in conjunction with the /etc/hosts.allow file.

Rationale

The /etc/hosts.deny file serves as a failsafe so that any host not specified in /etc/hosts.allow is denied access to the system.

Audit Procedure

Run the following command and verify the contents of the /etc/hosts.deny file:

cat /etc/hosts.deny

Expected Result

ALL: ALL

Remediation

Run the following command to create /etc/hosts.deny:

echo "ALL: ALL" >> /etc/hosts.deny

Default Value

Contents of /etc/hosts.deny file may include additional options depending on your network configuration.

References

CIS Controls: 9.2 - Leverage Host-based Firewalls

Profile

Level 1 - Server
Level 1 - Workstation