Infrastructure Resilience Briefing — October 22, 2025

Executive briefing: NIST published the final SP 800-82 Revision 3 in July 2024, updating industrial control system (ICS) security guidance for utilities, manufacturing, and pipeline operators. Zeph Tech recommends closing segmentation and remote access gaps now so OT environments meet the playbooks regulators expect going into the 2025–2026 winter demand window.

Key risk themes

Flat networks remain exploitable. NIST requires operators to isolate control zones, enforce least privilege routing, and broker traffic through monitored demilitarised zones to contain lateral movement.
Remote access governance. Revision 3 mandates multifactor authentication, jump host auditing, and contractor account expiration for any remote maintenance pathway into ICS assets.
Enhanced monitoring expectations. The guide elevates requirements for protocol-aware inspection, asset inventories, and time-synchronised logging so responders can reconstruct OT incidents.

Control alignment

NIST SP 800-82 Rev 3, Sections 5.2 and 5.3. Implement zone-to-zone firewalls with explicit allow rules, disable unused services on programmable logic controllers, and document compensating controls for legacy devices.
DOE C2M2 v2.1, Domain AM2. Update asset management baselines so ICS inventories include firmware versions, network addresses, and support status to feed segmentation design.
CISA Cross-Sector CPG 2.0 (CPG.AC.3 and CPG.MR.2). Map remote access workflows to zero-trust identity checks and ensure OT logging is centralised with retention that meets incident reporting mandates.

Detection and response priorities

Deploy protocol-aware intrusion detection sensors across control zones and calibrate alerting for abnormal ladder logic downloads, OPC UA browsing, and historian queries.
Exercise incident response plans that cover simultaneous IT and OT compromises, including procedures for manual process operations if ICS assets must be isolated.

Enablement moves

Brief executive risk committees on capital allocations required for switchgear upgrades, redundant controllers, and secure remote maintenance jump hosts.
Coordinate with engineering to schedule downtime windows that let teams deploy segmentation gateways and apply vendor firmware without disrupting production.

Sources

Zeph Tech partners with OT operators to harden ICS architectures, deploy monitoring tuned to NIST guidance, and prove compliance against DOE and CISA benchmarks.