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Showing SKILL.md
macOS post-exploitation for credential harvesting, DTrace monitoring, TCC bypass, and stealth operations via native tools
Windows userland post-exploitation for credential harvesting, monitoring, AMSI/ETW bypass, and stealth operations
Kubernetes post-exploitation for container escape, secret extraction, RBAC abuse, and cluster persistence
| name | cis-ubuntu1804-v220-3-4-3-2-1 |
| description | Ensure iptables default deny firewall policy |
| category | cis-networking |
| version | 2.2.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","linux","ubuntu-18.04","networking","firewall","iptables"] |
| cis_id | 3.4.3.2.1 |
| cis_benchmark | CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
A default deny all policy on connections ensures that any unconfigured network usage will be rejected.
With a default accept policy the firewall will accept any packet that is not configured to be denied. It is easier to allow list acceptable usage than to deny list unacceptable usage.
Run the following command and verify that the policy for the INPUT, OUTPUT, and FORWARD chains is DROP or REJECT:
iptables -L -n
Chain INPUT (policy DROP)
Chain FORWARD (policy DROP)
Chain OUTPUT (policy DROP)
Run the following commands to implement a default DROP policy:
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP
accept
Version 8
4.4 Implement and Manage a Firewall on Servers - Implement and manage a firewall on servers, where supported.
4.5 Implement and Manage a Firewall on End-User Devices - Implement and manage a host-based firewall or port-filtering tool on end-user devices.
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.
Automated