| name | cis-ubuntu1604-v200-3-5-2-3 |
| description | Ensure iptables are flushed with nftables |
| category | cis-networking |
| version | 2.0.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","linux","ubuntu-16.04","firewall"] |
| cis_id | 3.5.2.3 |
| cis_benchmark | CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 - Control 3.5.2.3
Profile
- Level: Level 1 - Server, Level 1 - Workstation
- Assessment Status: Manual
Description
nftables is a replacement for iptables, ip6tables, ebtables and arptables.
Rationale
It is possible to mix iptables and nftables. However, this increases complexity and also the chance to introduce errors. For simplicity flush out all iptables rules, and ensure it is not loaded.
Audit Procedure
Command Line
Run the following commands to ensure no iptables rules exist.
For iptables:
iptables -L
No rules should be returned.
For ip6tables:
ip6tables -L
No rules should be returned.
Remediation
Command Line
Run the following commands to flush iptables.
For iptables:
iptables -F
For ip6tables:
ip6tables -F
References
None
CIS Controls
Version 7
9.4 Apply Host-based Firewalls or Port Filtering - Apply host-based firewalls or port filtering tools on end systems, with a default-deny rule that drops all traffic except those services and ports that are explicitly allowed.