Modernizing OT/ICS Jump Servers for Enhanced Security and Operational Efficiency

In the realm of Operational Technology and Industrial Control Systems , jump servers serve as critical checkpoints for managing access across different security zones, typically bridging internal trusted networks with more exposed or less secure DMZs. As cyber threats evolve and the integration of IT and OT environments grows, modernizing jump servers becomes imperative to address both security needs and operational requirements.

Why Modernize?

The traditional use of jump servers involved basic SSH or RDP connections, focusing primarily on providing a secure path for administrative access. However, as highlighted by various sources, including a TechTarget discussion on their use and limitations, these setups, while effective initially, have several drawbacks:

• Security Risks: Jump servers can be a single point of failure if compromised. The infamous 2015 breach where a compromised jump server led to one of the largest data breaches in U.S. history underscores this vulnerability.
• Operational Inefficiency: Traditional jump servers require users to log into multiple systems, which can be cumbersome and time-consuming.
• Lack of Scalability: As networks grow and more devices need management, the traditional model can become unwieldy, leading to complex configurations and management.

As I am seeing lots of customer using Forti VPN or standard VPN's to access the jump servers into their production environments I will focus on some key issues with VPN.

5 Major VPN Security Flaws

1. All-or-Nothing Network Access: VPNs often grant full network access post-authentication, allowing attackers or unauthorized users to move laterally across the network, potentially accessing sensitive resources.
2. Lack of Continuous Monitoring: After initial authentication, VPNs do not provide ongoing monitoring of user activity, leaving networks vulnerable to unauthorized actions during the session.
3. Dependency on Internet: VPNs require an internet connection to function, which is a limitation for environments that are intentionally kept offline for security reasons, like many operational technology (OT) setups.
4. Exposure of Insecure Protocols: Industrial systems using protocols like Modbus and DNP3 are exposed through VPNs, which lack built-in security for these protocols, making them easy targets for exploitation.
5. Challenges with Third-Party Access: VPNs typically require the installation of software agents, which can be impractical for third-party vendors who might use their own devices or work with multiple companies, each requiring different VPN software.

Modern Approaches to Jump Servers

Zero Trust Architecture: Moving away from the perimeter-based security model, modern jump servers can be integrated into a Zero Trust framework where every access request is verified, regardless of where it originates, enhancing security.

Cloud-Based Solutions: Using cloud directory services like those offered by JumpCloud or integrating with cloud platforms can simplify management, provide scalability, and enable features like automatic scaling and SSH key management, which are crucial for modern OT/ICS environments.

Advanced Authentication: Implementing multi-factor authentication (MFA) or two-factor authentication (2FA) adds layers of security. Solutions like those from Xage Security propose using these alongside VPNs for a more secure connection method to OT assets.

Network Segmentation and Firewalls: Enhanced segmentation using modern firewalls or routers, as discussed by HorizonIQ, ensures that even if one segment is compromised, the breach does not easily spread to others.

Real-Time Monitoring and Logging: Modern jump servers should come equipped with robust logging capabilities. Solutions like those from Netmaker suggest using VPNs with strong encryption and mutual authentication for monitoring and securing jump server access.

Integration with Privileged Access Management (PAM): While traditional methods might use shared passwords or generic accounts, integrating with PAM systems allows for individual accountability, reducing the risk associated with shared credentials.

Automated Patching and Updates: Given the critical role of jump servers in OT/ICS environments, ensuring they are up-to-date with the latest security patches is crucial to prevent exploitation of known vulnerabilities. Automated patching can reduce the window of opportunity for attackers by ensuring that security updates are applied promptly. Session Recording and Monitoring: For compliance and security, it's beneficial to record and monitor all sessions conducted through jump servers. This not only aids in auditing but also in incident response by providing a clear record of who did what and when.

Least Privilege Access: This principle dictates that users are granted the minimum level of access necessary to perform their job functions. In the context of jump servers, this means configuring access so that users can only reach the systems they need to for their specific tasks

Steps to Implement Modern Jump Servers

1. Assessment and Planning: In an industrial setting, this step involves evaluating the existing OT/ICS infrastructure, identifying which systems are connected via jump servers, and understanding the operational risks associated with these connections. This phase focuses on compliance with standards like ISA/IEC 62443, assessing current security measures, and planning upgrades or replacements to meet evolving security needs.
2. Choosing the Right Technology: For industrial environments, technology selection should prioritize solutions that can integrate seamlessly with existing SCADA systems or PLCs. This might mean choosing ruggedized hardware that can withstand factory conditions, or software that supports legacy protocols while providing modern security features like encryption and two-factor authentication. Cyolo has some key OT Secure Remote Access platforms that I can strongly suggest.
3. Implementation: Implementation in manufacturing involves deploying the chosen technologies while ensuring minimal disruption to production lines. This could include setting up new jump servers in parallel with old systems, testing them in isolated environments, and then gradually integrating them into the live network. The setup should support secure remote access for maintenance without compromising the integrity of the OT systems.
4. Security Enhancements: Security in industrial settings requires robust measures like network segmentation to isolate different parts of the manufacturing process, intrusion detection systems tailored for OT environments, and encryption of data both at rest and in transit. These enhancements protect against both external threats and insider threats within the factory network.
5. Training and Policy Development: Staff in manufacturing environments often have technical skills but may lack cybersecurity awareness. Training should focus on the safe use of jump servers, recognizing phishing attempts, and understanding the importance of maintaining security protocols. Policies must be developed to cover all aspects of cybersecurity, from access controls to incident response, tailored to the unique operational needs of a manufacturing facility.
6. Testing and Validation: In industrial settings, testing goes beyond simple functionality checks to include stress tests under real operational conditions. This might involve simulating high-load scenarios or potential cyber attacks to see how the jump servers and the connected systems respond. Validation also ensures that all modifications do not adversely affect the production processes.
7. Maintenance and Review: Maintenance in an industrial environment involves regular updates to both hardware and software to address new vulnerabilities. Given the critical nature of manufacturing processes, any maintenance must be scheduled during downtime or through redundant systems to prevent production halts. Reviews should be conducted to assess the effectiveness of the implemented security measures, possibly involving external audits to ensure compliance and best practices are maintained.

Conclusion

Modernizing OT/ICS jump servers is not just about upgrading technology but transforming how security, access, and management are approached in industrial environments. By adopting a strategy that includes advanced authentication, zero trust principles, robust encryption, and automation, organizations can achieve a balance between stringent security measures and efficient operational management. This modernization not only protects critical infrastructure from evolving cyber threats but also enhances the overall resilience and agility of OT/ICS systems in the face of digital transformation challenges.

Good luck in securing your OT Jump Server.