The Evolving Landscape of Remote Access in Operational Technology

Remote access across operational technology (OT) is facing unprecedented challenges. As cyber adversaries exploit vulnerabilities in legacy systems with alarming precision, the strain on industrial networks intensifies. Traditional OT remote access security solutions, often driven by convenience, are increasingly falling victim to complex attacks, jeopardizing vital infrastructure. Striking a balance between operational defenses and organizational agility has never been more critical.

The Tightrope of Usability and Security

Navigating the delicate balance between usability and security is akin to walking a tightrope. Lax security measures can lead to violations, while overly stringent rules can stifle productivity. The solution lies in implementing granular access restrictions, adaptive authentication, and session monitoring that adjusts to risk without disrupting workflows. Organizations must ensure that security measures enhance rather than hinder operational efficiency.

Monitoring remote access in complex OT environments requires more than merely reviewing logs. Organizations must maintain constant awareness of who is connecting, when, and why. Suspicious activities should trigger immediate responses rather than retrospective analyses. While frameworks like NERC and NIST provide guidelines, compliance alone is insufficient. Organizations must integrate security into their remote-work operations, moving beyond mere checklists.

The Future of Work: Collaboration and Intelligence Sharing

The future of work will hinge on how effectively companies share threat intelligence, both within their sectors and across borders. As threats become more agile, a siloed defense will no longer suffice. In this new industrial age, survival depends on collective defense strategies. Fixes in the technical realm alone will not bridge the gap; sustained cooperation among asset owners, regulators, and technology providers is essential. Governance models must evolve in tandem with real-time operational risks. In the next three to five years, secure remote access will either become a core strength or remain a chronic vulnerability.

Securing Industrial Access in a Shifting Threat Landscape

To explore the state of OT remote access security, experts have identified key technologies and strategies that are proving effective. Zero Trust architectures, identity and access management (IAM), jump servers, VPNs, and DMZs are among the most discussed solutions. Over the past 18 to 24 months, there has been a noticeable shift toward Zero Trust Network Access (ZTNA) as the preferred method for secure remote access.

Andrew McPhee, OT security solutions manager at Cisco, emphasizes that traditional VPN systems are increasingly viewed as outdated. ZTNA, based on the principle of least privilege, offers built-in protection features that restrict user access to only necessary resources. This shift toward ZTNA solutions reflects a growing recognition of their superior security capabilities, although organizations with existing VPN infrastructures may face challenges during the transition.

Roman Arutyunov, co-founder of Xage Security, notes that organizations are moving away from fragmented tools toward consolidated platforms that integrate IAM with secure remote access. This trend is driven by the need for simplicity, scalability, and a stronger security posture. Meanwhile, Ian Schmertzler, co-CEO of Dispel, highlights the effectiveness of DMZs in controlling access to OT assets, noting that deployment times have significantly decreased.

Common Pitfalls in Remote Access Security

Weaknesses in OT remote access security remain a primary cause of successful breaches. Common pitfalls include failing to keep industrial systems updated and exposing devices with public IP addresses. McPhee warns that adopting remote access solutions that expose industrial assets to the public internet invites attacks. ZTNA solutions mitigate this risk by employing a combination of on-premises agents and cloud brokers, allowing remote users to connect securely without exposing entry points.

Organizations must also extend security measures down to the individual asset level. Arutyunov points out that relying on insecure solutions like traditional VPNs and static credentials introduces significant vulnerabilities. Regular penetration testing and productivity assessments can help identify and address gaps in remote access solutions.

Balancing Security and Usability

As organizations grant remote access to third parties, balancing usability and security becomes increasingly important. McPhee notes that secure access has often been synonymous with complexity, leading to inefficiencies and increased risk of human error. ZTNA addresses these challenges by integrating security with user-friendliness, enabling seamless access while maintaining robust security controls.

Arutyunov emphasizes the importance of just-in-time and just-enough-access principles for vendor access. As geopolitical tensions rise, organizations must continuously monitor for anomalous behavior and implement automated controls to isolate critical systems when suspicious activity is detected.

Auditing Remote Access in Complex OT Environments

Visibility and auditability are central to any robust OT remote access security program. McPhee stresses the importance of managing identities and defining access roles. Remote access should be on-demand to minimize the attack surface, and admin accounts should be strictly limited. Organizations should also adopt zero trust policies and enforce least privilege access to mitigate risk.

Continuous monitoring is essential for operational assurance. Real-time session recording and centralized logging enable security teams to maintain oversight without being physically present on-site. As auditability becomes a board-level concern, organizations must demonstrate live control over remote access, showcasing who connected, when, and what actions were taken.

Regulatory Influence on Remote Access Practices

Recent incidents tied to weaknesses in OT remote access security have prompted a closer examination of regulations and industry frameworks. McPhee notes that while frameworks like NERC CIP and IEC 62443 provide valuable guidance, remote access recommendations are often buried within extensive documents. Standalone guidance is needed to highlight the risks of poorly implemented controls.

Arutyunov emphasizes that regulations are increasingly focusing on zero trust, strong authentication, and session monitoring. Organizations must ensure compliance by enforcing identity-based access and recording all activity, even across air-gapped or legacy systems.

The Road Ahead for OT Remote Access and Intelligence Sharing

Looking ahead, OT remote access security is expected to evolve significantly. McPhee predicts that identity threat detection and response (ITDR) functions will play a key role in securing networks. As artificial intelligence advances, remote access technologies must be equipped to protect against increasingly sophisticated attacks.

Arutyunov foresees a shift toward Zero Trust architectures with AI-driven policy enforcement. Cross-sector collaboration and real-time threat intelligence sharing will be pivotal in refining policies and enhancing collective defense strategies. As industrial operations become more interconnected, the importance of shared playbooks and mutual defense mechanisms will only increase.

In conclusion, remote access in operational technology is at a critical juncture. Organizations must prioritize security while ensuring usability, embracing innovative technologies and collaborative strategies to navigate the evolving threat landscape. The future of OT remote access will depend on the ability to adapt, share intelligence, and implement robust security measures that protect vital infrastructure.