Profile Applicability:
• Level 1
Description:
An nftables table groups related firewall rules for efficient network traffic filtering. Ensuring that at least one nftables table exists confirms that nftables is actively managing firewall rules.
Rationale:
Having an nftables table is necessary for defining and applying firewall policies, which helps secure the system against unauthorized network traffic.
Impact:
Pros:
Confirms active use of nftables for firewall management.
Supports structured and maintainable firewall configurations.
Cons:
Absence of tables means nftables is not effectively used, increasing risk.
Default Value:
No nftables tables exist by default unless configured.
Pre-requisites:
Root or sudo privileges to query nftables configuration.
Remediation:
Test Plan:
Using Linux command line:
1. List nftables tables
nft list tables
2. Confirm that at least one table exists.
Implementation Plan:
Using Linux command line:
1. Create a default nftables table if none exist, for example:
nft add table inet filter
2. Verify the table creation:
nft list tables
Backout Plan:
Using Linux command line:
1. Delete the created nftables table if necessary:
nft delete table inet filter
2. Verify deletion:
nft list tables
References:
CIS Amazon Linux 2 Benchmark v3.0.0
nftables Official Documentation