Beyond VPNs: Secure Remote Access for OT & IIoT

Everybody loves a good throwback. Flip phones, vinyl records, and maybe even the dial-up tone for nostalgia’s sake. But if your operational technology (OT) and industrial internet of things (IIoT) environment is still relying on traditional VPNs to connect users, vendors, and machines, that’s one throwback you really don’t want.

OT systems have evolved. They’re smarter, more connected, and unfortunately more vulnerable than ever. While factory floors race ahead with digital transformation, many environments are still secured with tools built for the internet of 2005. That disconnect has become a serious liability.

Are VPNs failing the factory floor?

Today’s industrial environments, factories, energy grids, and utilities, are no longer isolated, air-gapped systems. They’ve become deeply interconnected ecosystems, where data flows from programmable logic controllers (PLCs) and human-machine interfaces (HMIs) to cloud applications, suppliers, and service providers. That kind of connectivity delivers enormous value, but also introduces significant risk.

Traditional VPNs weren’t built for this level of complexity. They offer overly broad access, lack granular visibility, and have become prime targets for attackers. In 2024, 45% of exploits targeted VPNs, many by initial access brokers (IABs), who infiltrate networks and sell access to ransomware groups or nation-state actors. Reported vulnerabilities also surged past 40,000 last year, a 38% jump from 2023.

The manufacturing sector is now the most targeted globally. According to Nozomi Networks OT/IoT Cybersecurity Trends and Insights Security Report, more than half of all reported incidents involved data manipulation, followed by denial-of-service attacks and network scanning. Common security issues, poor credential hygiene, brute-force attacks, and misconfigured access controls only widen the attack surface.

The message is clear: relying on legacy access tools puts operations, safety, and data at risk. Your plant floor needs access controls that are secure, smart, and designed to defend against today’s evolving threats.

The solution: Modern access for a new era of OT and IIoT

It’s time for a smarter, more adaptive approach to access, one grounded in zero trust principles and delivered through zero trust network access (ZTNA). That means never assuming trust based on network location and instead verifying user identity, device posture, location, activity, behavior, threat intelligence, and data risk before granting access. Users and machines should connect only to the systems they need, nothing more.

ZTNA is especially critical in environments where uptime, safety, and compliance are non-negotiable. Whether it’s a technician logging into a supervisory control and data acquisition (SCADA) system, a contractor accessing a machine, or an Internet of Things (IoT) device sending telemetry to the cloud, access must be secure, risk-aware, and frictionless.

Equally important is visibility. Organizations need to understand who’s accessing what, from where, and why, and be ready to act if something looks suspicious. That level of control only comes with ZTNA solutions built specifically for the realities of OT and IIoT.

Netskope One Private Access: Design for the demands of OT and IIoT

Netskope One Private Access delivers ZTNA tailored to industrial environments, connecting users and devices to systems like SCADA, PLCs, and HMIs without exposing the broader network. Built for performance and resilience, it provides high availability, low latency, and centralized visibility across distributed sites.

Let’s take a closer look at how some of the core functionalities can help the manufacturing sector:

Granular, role- and context-based access control: 

Access is enforced by user identity, device posture, location, activity, behavior, threat intelligence, and data risk context, ensuring users and machines only interact where needed. The platform supports all core OT use cases, such as user-to-machine, machine-to-machine, and machine-to-cloud, while offering agentless, browser-based access to protocols like RDP and SSH. All without any endpoint installs required.

Netskope One Private Access also includes built-in privileged access management (PAM) features like credential injection, session recording, and in-session protections to reduce risk and meet audit requirements, without disrupting operations.

Continuous adaptive security and threat protection: 

AI- and ML-driven risk scoring continuously monitors behavior and dynamically adjusts access. For example, if a typically low-risk device, like a camera, begins abnormal activity, like SSH attempts, its risk score rises, triggering automated segmentation. 

Inline data loss prevention (DLP) and threat inspection add additional layers of protection, blocking unauthorized activity, insider threats, and data leakage before they escalate.

Performance, availability, and compliance without compromise: 

Backed by Netskope’s global NewEdge network infrastructure, the platform ensures low-latency, always-on access across every industrial site. Intelligent traffic routing eliminates VPN bottlenecks and supports seamless, uninterrupted operations. This cloud-native design ensures 24/7 reliability and scale, with centralized policies and real-time insights across HQs, remote sites, and third-party access, safeguarding critical OT systems.

Compliance is built-in, with features like session recording, detailed access logging, and centralized policy enforcement, helping organizations meet standards like NERC CIP, IEC 62443, and NIST without adding friction to daily workflows.

Purpose-built for what’s next in OT

OT and IIoT environments demand secure access to critical systems, and more. They require performance, visibility, control, and scalability to keep operations running smoothly and securely. Netskope One Private Access delivers all of that functionality, helping organizations modernize access without compromising safety, performance, or compliance.

What you gain with Netskope One Private Access:

• Stronger security and control with zero trust access, continuous risk-aware enforcement, and secure credential handling
• Simplified field access through agentless connectivity, centralized management, and deep visibility into who is accessing what, when, and from where
• Improved performance and resilience with low-latency global access and built-in high availability

Whether you’re enabling distributed teams, connecting cloud services, or protecting critical infrastructure, this is secure access built for how OT and IIoT work today, and where they’re headed next.

Discover how to modernize and Secure Remote Access for OT & IIoT Systems with zero trust network access.