Network Perimeter
Flat Network Lateral Movement
Without segmentation, a single compromised endpoint reaches everything.
What it is
A flat network — where all systems can communicate with all other systems — gives attackers unrestricted lateral movement after initial compromise. One compromised workstation becomes a path to domain controllers, backup systems, financial applications, and production databases. Micro-segmentation limits this blast radius to a defined zone, requiring attackers to cross additional trust boundaries at every step.
Attack techniques
- SMB lateral movement (T1021.002)
- RDP hop (T1021.001)
- WMI remote execution (T1047)
- Unrestricted east-west traffic
- Missing host-based firewall enforcement
Business impact
In a flat network, ransomware can propagate to every reachable system within minutes. Segmentation converts a catastrophic incident into a contained one.