| name | cis-ubuntu2004-v300-4-3-4 |
| description | Ensure a nftables table exists |
| category | cis-networking |
| version | 3.0.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","linux","ubuntu-20.04","firewall","nftables"] |
| cis_id | 4.3.4 |
| 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 4.3.4
Profile
- Level: Level 1 - Server, Level 1 - Workstation
- Assessment Status: Automated
Description
Tables hold chains. Each table only has one address family and only applies to packets of this family. Tables can have one of five families.
Rationale
nftables doesn't have any default tables. Without a table being built, nftables will not filter network traffic.
Impact
Adding rules to a running nftables can cause loss of connectivity to the system
Audit Procedure
Command Line
Run the following command to verify that a nftables table exists:
nft list tables
Return should include a list of nftables:
Example:
table inet filter
Expected Result
A list of nftables tables is returned (e.g., table inet filter).
Remediation
Command Line
Run the following command to create a table in nftables
nft create table inet <table name>
Example:
nft create table inet filter
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 | TA0011 | M1047