Why VPN and MFA Alone Fall Short in Securing OT Environments

on February 3, 2026

Key Highlights

  • Traditional VPN and MFA are necessary but insufficient; OT environments require additional, context-aware security controls that consider operational risks and system behavior.
  • Incident data show that a significant percentage of cybersecurity breaches originate from remote access pathways, underscoring the need for ICS-specific protections beyond identity verification.
  • Organizations with comprehensive remote access inventories and ICS-aware monitoring demonstrate stronger detection capabilities and more effective incident response.
  • Recovery in industrial systems is complex and slow, underscoring the importance of visibility into user actions and system changes for safe reconstitution.

For many industrial organizations, securing remote access follows a familiar formula: deploy a Virtual Private Network (VPN), require multi-factor authentication (MFA), and consider the risk largely addressed. These controls are essential and form the backbone of secure connectivity in both IT and OT environments.

However, operational technology systems support safety-critical processes, specialized devices, and tightly coupled engineering workflows that demand far more than basic identity verification. VPN and MFA confirm who is accessing the environment, but they do not address the actions a user may take, the systems with which they can interact, or how those actions may affect physical operations. As industrial environments become more interconnected and increasingly reliant on remote capabilities, identity alone is no longer enough.

Incident Data Shows the Limits of Traditional Remote Access Controls

Recent industry data clearly illustrates this gap. Over the past year, 22% of organizations experienced an ICS/OT cybersecurity incident, with half originating from external connectivity or remote access. Another 38% involved ransomware, which frequently exploits remote access pathways bridging IT and OT environments.

These findings do not suggest that VPNs or MFA are ineffective. Rather, they highlight the need for ICS-specific layers of protection that extend beyond identity management and account for engineering context, operational risk, and system behavior.