Disconnected Access Explained: How Xona Protects Critical Systems Without Network Connectivity

Written by Raed Albuliwi | Nov 6, 2025 5:00:00 AM

Reframe Secure Access for Critical Infrastructure

Remote access isn’t optional in critical infrastructure anymore; it’s operationally essential. Whether for maintenance, OEM support, remote field work, or incident response, industrial organizations must enable access to critical systems.But, legacy access methods like VPNs, jump servers, and even agent-based Zero Trust or IT-based remote privileged access management (RPAM) tools all share one dangerous flaw: they implicitly trust the endpoint.In a world where ransomware is delivered through contractor laptops, jump hosts become pivot points, and unmanaged endpoints are the #1 threat vector to OT, it’s time to fundamentally rethink how we provide access.

What if users could access critical systems without ever connecting to the network?

That’s the promise of Disconnected Access, a protocol isolated architecture that’s reshaping secure access for operational technology (OT), industrial control systems (ICS), and cyber-physical systems (CPS). It’s how Xona helps critical infrastructure leaders break the connection, not just restrict it.

What Is Disconnected Access?

Disconnected Access is a secure access model that breaks the traditional network tunnel between user endpoints and critical infrastructure.Instead of routing traffic from untrusted devices into trusted networks (as VPNs or jump hosts do), Xona isolates access at the protocol level, completely severing the network path between the user and the system.Using browser-based interaction, screen rendering, and strict protocol mediation, users interact with applications (like HMIs, PLCs, and engineering workstations) without the underlying device ever making a network connection to the OT environment.This approach:

Eliminates lateral movement
Prevents malware payload delivery
Stops data exfiltration via endpoint compromise
Protects ransomware-prone OT systems without patching

It’s Zero Trust without assuming endpoint integrity; an ideal match for field engineers, remote contractors, and third-party OEMs accessing sensitive industrial systems.

“Restrict the connection” vs. “Break the connection”

Most remote access platforms, including modernized IT-RPAM, VPN, and Zero Trust solutions, attempt to restrict access through configuration.They rely on segmentation, firewalls, endpoint verification, or policy layers. But they all still fundamentally connect the user’s device to the OT network.🔐 Xona breaks the connection entirely. Our platform establishes a one-way, protocol-isolated session that proxies screen data only, not files, commands, or protocols. This air gap by design enforces Zero Trust from endpoint to asset without any direct network exposure.

How Xona’s Architecture Works

Xona’s secure access platform is purpose-built for critical infrastructure. Here’s how it protects operations from endpoint risk while keeping workflows fast and effortless:✅ Application-Layer Isolation Only mouse, keyboard, and screen data are exchanged, not protocols or packets. OT traffic stays confined to the trusted network.✅ Browser-Based Access No VPN clients. No agents. No plugins. Just a modern browser, even in air-gapped or low-bandwidth environments.✅ No Endpoint Trust Assumptions We make no assumptions about the user's device. Compromised laptop? Infected field tablet? Irrelevant. Xona mediates all access from a secured perimeter.✅ Complete Session Control Record every session. Shadow user activity. Enforce RBAC, TBAC, and instantly terminate sessions when policy violations occur.✅ Regulatory Ready by Design Supports NERC CIP, IEC 62443, TSA SD02, NIS2, and OTCC-1 standards, including just-in-time access, session audit, and secure identity brokering.

Feature	VPN	Jump Server	PAM	Xona
Built for OT/ICS	❌	❌	❌	✅
No endpoint-to-network connection	❌	❌	❌	✅
Browser-based (zero install)	❌	❌	❌	✅
Session isolation and recording	Limited	Partial	Partial	✅
Regulatory compliance ready	❌	❌	Partial	✅
Maintenance overhead	High	High	Medium	Low

Only Xona offers true Disconnected Access, a secure, protocol-isolated session that defends against endpoint threats without complexity or compromise.

Xona in Action: Real-World Use Cases

Field Engineer Troubleshooting An engineer with an unmanaged laptop needs to check an HMI panel 300 miles away. With Xona, they log in through a browser and access the interface securely, no VPN, no agent, no network exposure.OEM Support Access A vendor needs to patch firmware on a PLC for one hour. With Xona’s time-bound, least-privileged access and moderated file transfer, they get session-limited entry via protocol isolation, with full video recording and zero lateral risk.Compliance Driven Operations A pipeline operator must demonstrate NERC CIP-003-09 compliance. With Xona, every remote session is logged, recorded, policy-bound, and compliant with zero direct connectivity.

Why It Matters Now

91% of organizations expressed concerns about VPNs compromising their security environment, with recent breaches illustrating the risks of maintaining outdated or unpatched VPN infrastructures.¹
VPN vulnerabilities have multiplied in recent years, leading to exploitation and emergency directives such as CISA’s ED-24-01.
Regulators now mandate Zero Trust enforcement across OT environments, but without breaking operations.

Secure remote access with disconnected access is no longer a nice-to-have. It’s a must-have for any OT organization that wants to secure, sustain, and scale operations in a hostile threat landscape.

Conclusion: It’s Time to Rethink Access Control

At Xona, we believe the people who keep the lights on, water flowing, and critical systems running deserve access that’s effortless, reliable, and secure, no matter where they are.We’re proud to empower critical infrastructure heroes with tools that help them work faster and safer, without compromising the assets we all depend on.Want to Learn More? Schedule a 15-minute demo.End Notes 1. Zscaler ThreatLabz 2024 VPN Risk Report, Zscaler, https://zerotrust.cio.com/wp-content/uploads/sites/64/2024/05/threatlabz-vpn-risk-report-2024.pdf

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