Modern factories rely on industrial control systems and industrial Ethernet networks to support automation and efficiency. However, many facilities still use legacy Ethernet infrastructure that lacks modern security protections, increasing risks to production continuity, intellectual property and operational safety.
Industrial Ethernet has become the backbone of smart manufacturing, connecting programmable logic controllers, human-machine interfaces, sensors, robotics, and supervisory control and data acquisition systems across factory floors.
As Industry 4.0 progresses, these systems increasingly link to cloud platforms, enterprise IT networks and remote tools. The U.S. National Institute of Standards and Technology notes that IT-OT convergence driven by Internet of Things (IoT) is expanding cybersecurity risk by connecting once-isolated industrial systems into always-on environments.
This convergence between IT and OT environments significantly expands the attack surface. Industrial environments using advanced protocols such as EtherCAT can further increase network complexity by supporting a greater number of connected devices per network without requiring unique IP addresses. While this improves real-time automation and scalability, it also increases the number of endpoints that must be monitored and secured.
Attackers actively target these weaknesses because older Ethernet systems are frequently easier to compromise than modern enterprise infrastructure.
Common Risks
Below are some of the most common Ethernet cybersecurity risks affecting older manufacturing environments:
- Unpatched systems: Older Ethernet devices often run unsupported firmware or operating systems that no longer receive security updates. These known vulnerabilities can be exploited by attackers using widely available tools.
- Flat network structures: Many older factory networks use flat architectures with limited segmentation. If attackers gain access to one device, they may move laterally across the network, increasing the risk of widespread disruption and ransomware attacks.
- Insecure industrial protocols: Legacy industrial protocols frequently prioritize speed and reliability over security. Without encryption or authentication, attackers may intercept communications, manipulate commands or impersonate trusted devices within the network.
- Limited network visibility: Older Ethernet environments often lack centralized monitoring and asset visibility. Without accurate inventories or traffic monitoring, security teams may struggle to detect unauthorized devices, suspicious activity or emerging threats before they impact operations.
Operational Consequences
Cyberattacks targeting industrial Ethernet infrastructure can have consequences far beyond data theft. In manufacturing environments, a successful ransomware attack may halt entire production lines for days or weeks. Downtime can quickly result in lost production, missed delivery deadlines, supply chain disruptions and financial losses.
Compromised Ethernet systems can also affect safety-critical operations. Manipulated communications between industrial devices may cause equipment malfunctions, unexpected shutdowns or hazardous operating conditions.
Intellectual property theft remains a growing concern. Attackers targeting manufacturers often seek proprietary production methods, product designs and operational data. As factories continue to integrate connected devices and industrial IoT technologies, the potential impact of Ethernet cybersecurity failures continues to grow.
Reducing Ethernet Cybersecurity Risks
While replacing every legacy system may not be realistic immediately, manufacturers can implement layered security measures to protect industrial networks better and reduce exposure to cyber threats:
- Segment OT networks: Separating IT and OT systems helps limit lateral movement during cyberattacks. Firewalls, VLANs and industrial demilitarized zones can isolate critical production assets from enterprise and internet-connected networks.
- Upgrade legacy hardware: Unsupported switches, controllers, and firmware should be updated or replaced whenever possible. Modern hardware typically includes stronger security features, while regular firmware updates help reduce exposure to known vulnerabilities.
- Improve network monitoring: Continuous monitoring tools provide visibility into Ethernet traffic, connected assets and unusual behavior. Better visibility allows security teams to identify unauthorized devices, suspicious communications and potential threats before they escalate.
- Secure remote access: Remote connections into industrial networks should use multi-factor authentication, encrypted VPNs and least-privilege access controls. Removing default credentials and turning off unused remote services can further reduce cybersecurity risks.
Legacy Infrastructure for Modern Threats
Industrial Ethernet remains critical in manufacturing, but outdated systems pose significant cybersecurity risks. By improving segmentation, visibility, patch management and access controls, manufacturers can better protect operations from modern cyber threats.
Strengthening Ethernet cybersecurity today helps reduce downtime, improve resilience and support safer industrial environments.
