APC UPS

A Brief Discussion on UPS Power Supply and Network Security

UPS power supply consists of rectifiers, inverters, batteries, etc., mainly used to filter, rectify, store, and invert the mains power. In the context of the integration of the two industries, although UPS power supply is an industrial equipment that mainly works under information technology conditions, as a guarantee barrier for industrial production and network power supply, it is closely related to network security.

As is well known, network security refers to the protection of the hardware, software, and data in a network system from accidental or malicious damage, alteration, or leakage. The system operates continuously, reliably, and normally, and network services are not interrupted. Among them, the protective effect of UPS power supply on occasional abnormal mains power supply is obvious. The following mainly analyzes the hidden danger of UPS power supply being maliciously attacked.

The working principle of UPS

UPS power supply serves as the last barrier for ensuring the power supply of electrical equipment. When the mains power is normal, it directly supplies power to the load using the mains power. UPS performs certain processing on the mains power, such as voltage stabilization, filtering, etc., to ensure the stability of the output power; At the same time, when the mains power is normal, the battery is charged to keep it in a fully charged state. When the mains power is abnormal, the battery’s energy is used to power the AC load through inversion.

With the rapid development of computer systems and communication equipment, as well as the growing demand for intelligent monitoring, most UPS devices are equipped with intelligent modules such as high-speed digital signal processors (DSPs) and microcontrollers. Furthermore, most UPS power supplies currently have embedded systems for power environment monitoring, etc. In actual use by users, UPS power supplies are generally in a real-time monitored state.

Principle of Power Environment Monitoring System

There are various ways to monitor the power environment, among which the commonly used method for small computer rooms and industrial environments is to use industrial control computers as monitoring hosts to collect and process power information. Multiple serial port cards are used to collect data from the bottom end power equipment, and real-time data is transmitted back through networking.

UPS and other devices transmit their working status back to the industrial computer (the computer running the power monitoring system acquisition program) through intelligent communication ports (RS232, RS485, or USB) or additional acquisition modules, and the industrial computer implements protocol interpretation and data processing. The industrial control host can also send control commands to UPS equipment.

The power environment monitoring system is similar to a simple SCADA industrial control system in industrial control, but there are risks of vulnerabilities and network attacks.

Human made vulnerability attacks in the context of informatization

As early as 2010, the Stuxnet worm, a super virus targeting Iran’s nuclear facilities, raised concerns among intelligence centers in multiple countries. It has been confirmed that this virus can issue commands to suddenly change the operating speed of a high-speed centrifuge, achieving the goal of damaging the centrifuge. At the same time, it sends error messages to the central control system, making it impossible for control personnel to detect abnormalities in the centrifuge. The virus was developed using vulnerabilities in the Windows operating system and Siemens devices, with the aim of disrupting Iran’s nuclear program. Russia’s Permanent Representative to NATO, Rogozin, stated that the virus has had a serious impact on Iran’s Bushehr nuclear power plant, causing radioactive material leakage and posing a danger no less than the Chernobyl nuclear power plant accident.

Whether it is Prism Gate or Stuxnet worm, organized network attacks are aimed at developing attack methods for specific vulnerabilities or setting up artificial vulnerabilities to facilitate network attacks. Attacks targeting vulnerabilities in industrial control systems or equipment are generally destructive and require people to be vigilant, raise awareness, and strengthen prevention at all times.

The above content, by introducing the structure of UPS power supply and the principle of dynamic environment monitoring, clarifies that UPS power supply is one of the network power and environmental devices that are the foundation of the computer room. Most of them are embedded and programmable intelligent devices under the power environment monitoring system. At the same time, by introducing cases and methods of domestic and foreign network attacks, especially those targeting industrial control computers and embedded devices, it is shown that intelligent devices such as industrial control computers and UPS power supplies may have human vulnerabilities. Without protective measures, there is a risk of cutting off power supply to industrial production and information technology equipment, and the consequences are unimaginable. This is not a groundless speculation. Hackers once released a tool to perform DoS attacks on Siemens SIPROTEC series protection relays.

Network security is a long and arduous task. While emphasizing the autonomous control of IT critical application hosts and software, people cannot ignore the vulnerability risks of power supply and power environment control systems.