Unpatched Legacy Systems: A Cybersecurity Risk in the Manufacturing Sector

In manufacturing environments, uptime is sacred. Every moment of operational disruption costs time, resources, and revenue. To preserve continuity, many manufacturers continue to rely on legacy systems; decades-old machines, controllers, and operating environments that were never built with modern cybersecurity in mind.

While these systems may still perform their intended function, they also carry a silent, growing risk: unpatched vulnerabilities. For attackers, these systems often represent the lowest-hanging fruit in an otherwise secure network. For manufacturers, they are a doorway into potentially devastating consequences, ranging from production stoppages to intellectual property theft or even equipment damage.

How Legacy Systems Create Entry Points for Cyber Attacks

Legacy systems are attractive targets for one simple reason: they cannot often defend themselves. Many run outdated versions of Windows, Linux, or proprietary industrial firmware that vendors no longer support. This means security patches, which fix known vulnerabilities, are no longer issued. Once a vulnerability is discovered, it becomes a permanent entry point for malicious actors.

These systems are typically embedded in the core of industrial operations. A programmable logic controller (PLC) might control the operation of a mixing unit, or an outdated HMI might provide visibility into critical assembly line functions. If attackers gain access, even indirectly, they can manipulate outputs, disrupt production processes, or escalate privileges to compromise more valuable systems.

The real danger lies in the layered architecture of manufacturing networks. IT systems may be up to date, but once attackers get inside via phishing or misconfigured remote access, they can pivot laterally into the OT environment, where unpatched legacy systems reside. From there, they can disrupt physical operations with very few obstacles.

Why Patching Legacy Systems Is So Difficult in Manufacturing

Patching seems like an obvious solution, but in manufacturing, it’s rarely that simple. Legacy systems often support custom industrial processes that depend on precise configurations. Applying a patch or system update could cause incompatibilities, breaking production software or interrupting workflows.

In many cases, the hardware itself is so old that no patches exist. The operating system may be out of support, or the vendor may no longer exist. Replacing the system altogether could mean halting operations for days, retraining staff, or recertifying processes—none of which is viable in high-output manufacturing environments.

There’s also the issue of visibility. Many manufacturers don't have complete inventories of the software versions running inside their plants. Without that clarity, identifying which systems need patching and assessing the risk of doing so becomes a guessing game.

The result? Legacy systems stay in place, exposed, and unpatched. Attackers know this. And they exploit it.

Real-World Example: Triton Malware Attack (2017)

One of the most alarming examples of an attack exploiting legacy vulnerabilities occurred in 2017 at a petrochemical facility in the Middle East. The attackers deployed the Triton malware, which specifically targeted a Triconex safety instrumented system, a type of industrial controller designed to shut down operations in the event of dangerous conditions.

The targeted system was running on legacy hardware and firmware. The attackers were able to remotely access the environment and inject malicious code into the safety system, potentially giving them the power to cause physical destruction or sabotage the facility’s safety mechanisms.

Fortunately, the attack was discovered before it could cause harm. However, investigations revealed that outdated systems with weak authentication and unpatched firmware played a significant role in enabling attackers to gain control.

How Legacy Systems Can Be Secured Without Downtime

Manufacturers need a way to protect legacy systems without replacing them and without disrupting production. This is where unidirectional gateways, powered by data diodes, provide a practical and secure alternative to traditional network segmentation and patching strategies.

Rather than trying to modernize every machine, manufacturers can isolate legacy systems from the rest of the network using hardware-enforced one-way data flow. This allows critical systems to send operational data out for monitoring, analytics, or compliance, but physically prevents any inbound commands, exploits, or lateral movement from reaching them.

At DataFlowX, we’ve built on this principle with DataDiodeX, an industrial-grade, unidirectional gateway designed specifically for high-assurance environments, such as manufacturing. However, unlike basic diodes, DataDiodeX takes it a step further.

It includes:

• Integrated Content Disarm & Reconstruction (CDR): Neutralizes embedded threats in files without relying on signatures.

• Sandbox Integration: Suspicious files or attachments are automatically analyzed in an isolated environment before being passed to downstream systems.

• Protocol-Aware Filtering: Inspects and validates industrial protocol data to ensure only approved, safe payloads leave the network.

This means manufacturers can continue operating legacy systems while still benefiting from real-time visibility and auditability, without compromising security and opening the door to attack vectors.

A Practical Path to Secure Legacy Infrastructure

DataDiodeX provides a path forward: one that doesn’t require tradeoffs between productivity and security. It allows manufacturers to meet modern cybersecurity demands while keeping the systems that keep them running.

Contact DataFlowX today to learn how we can help you secure legacy environments without disrupting what your business does best: manufacturing at scale.