| name | cis-ubuntu2004-v300-4-3-3 |
| description | Ensure iptables are flushed with nftables |
| category | cis-networking |
| version | 3.0.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","linux","ubuntu-20.04","firewall","nftables"] |
| cis_id | 4.3.3 |
| cis_benchmark | CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0 - Control 4.3.3
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
Expected Result
No rules returned from either command.
Remediation
Command Line
Run the following commands to flush iptables:
For iptables:
iptables -F
For ip6tables:
ip6tables -F
Default Value
Not applicable.
References
- NIST SP 800-53 Rev. 5: CA-9, SC-7
CIS Controls
v8 - 4.4 Implement and Manage a Firewall on Servers
v8 - 4.5 Implement and Manage a Firewall on End-User Devices
v7 - 9.4 Apply Host-based Firewalls or Port Filtering
MITRE ATT&CK Mappings: T1562, T1562.004 | TA0005