Minimizing OT Attack Surface: A CISO’s Perspective on Limiting Exposure

Exposure is the single most reliable predictor of OT compromise.

The more reachable an asset is, the more likely it will be targeted. CISOs must therefore champion exposure management, not perimeter optimism.

High-Risk Exposure Patterns

• Internet-accessible OT devices

• Inbound remote access

• Permanently enabled vendor connections

• Admin interfaces outside privileged access controls

Board-Relevant Controls

• Outbound-only connectivity

• Brokered access via DMZs

• Just-in-time remote access

• Privileged Access Workstations (PAWs)

Executive Insight

Reducing exposure lowers:

• Probability of compromise

• Incident response costs

• Regulatory scrutiny

This is risk reduction with measurable ROI.

Final Thought: Exposure Is the Enemy of Resilience

Most OT compromises are not sophisticated—they are inevitable outcomes of unnecessary exposure. Attackers do not need zero-days when systems are reachable, persistent, and poorly governed.

Reducing exposure is one of the few OT security actions that reliably lowers both likelihood and impact. For CISOs, this is a rare control that improves security posture while simultaneously reducing operational and regulatory burden.