12.2
IG2 IG3

Establish and Maintain a Secure Network Architecture

Asset Type: Network
Security Function: Protect

Description

Establish and maintain a secure network architecture. A secure network architecture must address segmentation, least privilege, and availability, at a minimum.

Implementation Checklist

1
Assess current protection controls in place
2
Configure and deploy required security controls
3
Test control effectiveness in non-production environment
4
Deploy to production and verify functionality
5
Document configuration and operational procedures
6
Review and document current network architecture
7
Define segmentation zones and trust boundaries
8
Implement segmentation controls
9
Test that segmentation is effective

Threats & Vulnerabilities (CIS RAM)

Threat Scenarios

Lateral Movement Through Flat Network Architecture

Confidentiality

Attackers who compromise a single endpoint move freely across the entire network because no segmentation exists, accessing databases, file servers, and critical systems that should be isolated from general user traffic.

Widespread Ransomware Propagation Across Unsegmented Network

Availability

Ransomware spreads to every reachable system on the network because the lack of segmentation provides no barriers to propagation, turning a single-host infection into an enterprise-wide encryption event.

Privilege Escalation via Network Architecture Flaws

Integrity

A network architecture that does not enforce least privilege allows users and systems to access network resources far beyond their operational needs, enabling attackers to reach high-value targets from any compromised entry point.

Vulnerabilities (When Safeguard Absent)

Flat Network with No Segmentation

The network architecture provides no segmentation between user workstations, servers, databases, management interfaces, and critical infrastructure, allowing unrestricted lateral communication between all network zones.

No Network Architecture Based on Least Privilege

Network access rules do not enforce least privilege principles, allowing systems and users to communicate with any network resource rather than only those required for their specific business function.

Evidence Requirements

Type Evidence Item Collection Frequency
Technical Configuration screenshots or exports showing protection controls enabled Captured quarterly
Document Procedure documentation for protection measures Reviewed annually
Document Governing policy document (current, approved, communicated) Reviewed annually