SCADA also known as Supervisory Control and Data Acquisition includes industrial
control systems that are used to manage and monitor infrastructure, industrial operations, and
facility-based processes. SCADA systems are considered important due to the fact that they
allow organizations to collect information from physical equipment and provide operators with
the information needed to supervise and adjust processes. Environments like water treatment, gas
pipelines, wind farms, wastewater treatment, airports, space stations, ships, and more are where
they are used (SCADA Systems, 1).
A SCADA system consists of the combination of several components to coordinate
physical processes. Crucial components are the supervisory system, Remote Terminal Units
(RTUS), programmable logic controllers (PLCs), communication infrastructure and the Human
Machine Interface (HMI). RTUs are connected to physical equipment and they convert electrical
signals into digital information, for example, valve status, flow, pressure, current, and voltage.
Also, they send control signals back to equipment, such as opening and closing a valve or
changing the spread of the pump. The HMI enables human operators to see processed
information and control processes. It can show and display diagrams, diagnostic information,
alarms, equipment status, and other data that is helpful to make supervisory decisions. For
instance, an operator has the ability to use an HMI to monitor a pump and observe the fluid
amount moving through a pipe and can switch the pump off when necessary also. SCADA
systems are especially important in critical infrastructure because failures in the control systems
can cause serious negative outcomes. Critical installations may use redundant hardware and
communication channels to improve reliability and allow backup equipment to take control when
a component fails.
Used in many industries, SCADA systems’ purpose is to monitor and coordinate physical
operations. In water and wastewater treatment, SCADA can assist operators monitor pumps,
valves, flow, and other equipment and system conditions. SCADA is also used with gas and oil
pipelines in order to help monitor and manage transportation systems. An HMI can display
equipment and system status so operators can monitor conditions and respond to changes. In
manufacturing and refining, SCADA can supervise industrial processes and provide information
about equipment and operating conditions.
One major cybersecurity risk for SCADA systems is unauthorized access, whether it be
human access, intentionally induced changes, virus infections, or other negative things that can
have an impact on the control host machine (SCADA systems, 6). If an unauthorized individual
gains access to a SCADA system, they could possibly interfere with the monitoring or control of
the physical processes. A second major cybersecurity risk is the lack of security in certain
SCADA communication protocols and network segments. In some control protocols, a person
able to send packets to a SCADA device may be in a position to control it. This causes a
significant risk because SCADA systems are connected to physical processes instead of only
digital information. The last of the concerns mentioned is increased network connectivity.
Modern networked SCADA systems use IP and can be accessed through network technologies,
which can increase vulnerability. The article states that “SCADA vendors are addressing these
risks by developing specialized industrial VPN and firewall solutions for SCADA networks that
are based on TCP/IP.” (SCADA systems, 6). By addressing the risks with these security
techniques, it can improve protection.
A cyberattack that is successful against a SCADA system could affect beyond just
computers. Due to the actions of SCADA systems, an attack can interfere with water
distribution, traffic signals, electricity transmission, gas transportation, oil pipelines,
manufacturing, or other important infrastructure. For an organization, a cyberattack could lead to
equipment failures, interruptions in operations, financial losses, and the loss of services that are
important. For society, an attack against critical infrastructure could interrupt services that people
depend on every day. Things like this are reasons why cybersecurity for SCADA systems must
consider both information security and physical safety.
Organizations can use several strategies to strengthen the security of SCADA. One
approach identified is the use of industrial VPN and firewall solutions designed specifically for
SCADA networks. These tools can help protect network communication and limit unauthorized
access. Another approach is application whitelisting. Whitelisting can help prevent unauthorized
applications or changes from being introduced into a SCADA environment. This is beneficial
because unauthorized software changes could affect the control system. Organizations can also
improve resilience by redundant servers, backup systems, and redundant communication
channels. These measures allow monitoring and control to continue when a server or other
system component fails.