How to Secure SCADA/ICS Systems

In my post Exploiting SCADA/ICS Systems, I was able to show how one person is about to change value in the coils of a SCADA/ICS system. Now I am not an expert in this topic whatsoever but I was taught by being a member of Hackers Arise.

Basic Security

I'm amazed by the lack of fundamental security measures in place for SCADA systems within many organizations. They often lack firewalls, authentication protocols, and any form of whitelist or blacklist controls. Port 502 is frequently the most vulnerable entry point into a SCADA system. In a previous post, I shared how I could access Port 502 without facing any form of authentication whatsoever. At least having some type of simple security measure will reduce the attacks by 50%.

Disconnect Unnecessary Connection to the SCADA network

Isolate the SCADA network from other network connections to a great degree as possible because any other connection to another network introduces security risks. Direct connections with other people's networks may allow important information to be passed efficiently and conveniently, and insecure connections are simply not worth the risk. The isolation of the SCADA network must be a primary goal to provide protection. Strategies such as the utilization of "demilitarized zones" (DMZs) and data warehousing can facilitate the secure transfer of data from the SCADA network to business properly to avoid the introduction of additional risk through improper configuration.

Removing or disabling Unnecessary Services.

SCADA control servers can be exposed to attacks through default network services and removing or disabling unused services and network daemons will reduce the risk of direct attacks. This is important when SCADA networks are interconnected with other networks but NEVER permit a service or feature on a SCADA network unless a thorough risk assessment of the consequences of allowing the service/feature shows that the benefits far outweigh the potential for vulnerability exploitation. Examples of services to remove SCADA networks include automated meter reading/remote billing systems, email services, and Internet access.

Do NOT Reply on Proprietary Protocols to Protect the Network

Some SCADA systems are unique, proprietary protocols for communication between field devices and servers. Often the security of SCADA systems is based on the secrecy of these protocols. However obscure protocols provide very little security. Never rely on proprietary protocols on factory default configuration settings to protect your systems. Demand the vendors disclose any backdoors or vendors interface to your SCADA systems, and expect them to provide systems that are capable of being secured.

Implement Security Features Provided by Device and System Vendors

Most older SCADA systems (most systems used) have no security features whatsoever. SCADA owners must insist that their system vendor implement security features in the form of products or upgrades. So newer SCADA devices are shipped with basic security features but these are usually disabled to ensure ease of installation.

We must analyze SCADA devices to determine whether security features are present. Additionally, factory default security settings (such as in computer network firewalls) are often set to provide maximum usability, but minimal security. Set all security features to provide the maximum level of security. Allow settings below maximum security only after a thorough risk assessment of the consequences of reducing the security level.

Establish Strong Controls over any Medium that is used as a backdoor into the SCADA networks

Where backdoors or vendor connections do exist in SCADA systems, strong authentication must be implemented to ensure secure communications. Modems, wireless, and wired networks used for communications and maintenance represent a significant vulnerability to the SCADA network or remote site. Successful "war dialing" or "war diving" attacks could allow an attacker to bypass all other controls and have direct access to the SCADA networks or resources. To minimize the risk of such attacks, disable inbound access and replace it with some type of callback system.

Conclusion

Concluding the discussion on the vulnerabilities and security measures for SCADA/ICS systems, it's clear that the protection of these critical infrastructures requires a different approach. The exploration into the ease with which one can manipulate SCADA systems underscores the urgent need for enhanced security protocols. Despite the complex nature of many SCADA systems, the basic principles of cybersecurity—such as implementing firewalls, authentication protocols, and controlling access—remain fundamentally underutilized.

The vulnerability of Port 502, as highlighted, serves as a stark reminder of the need for basic security measures. By simply implementing fundamental security protocols, organizations can significantly reduce their risk of cyber attacks. Furthermore, the isolation of SCADA networks from unnecessary connections and the diligent management of network services and protocols are critical steps in safeguarding these systems. It's evident that reliance on obscurity or proprietary protocols for security is a flawed strategy, transparency from vendors regarding potential vulnerabilities and the use of security features are important for the integrity of SCADA systems.

The exploration of these vulnerabilities and the outlined security measures provide a roadmap for organizations to bolster their defenses against cyber threats. It emphasizes the importance of a proactive and comprehensive approach to security, urging SCADA system operators to reassess and enhance their cybersecurity practices. In a world increasingly reliant on digital infrastructure, the security of SCADA/ICS systems is not just a technical issue but a matter of national and operational resilience.