  Cyberattacks on industrial control systems (ICS) have been drawing attention
in academia. However, this has not raised adequate concerns among some
industrial practitioners. Therefore, it is necessary to identify the vulnerable
locations and components in the ICS and investigate the attack scenarios and
techniques. This study proposes a method to assess the risk of cyberattacks on
ICS with an improved Common Vulnerability Scoring System (CVSS) and applies it
to a continuous stirred tank reactor (CSTR) model. The results show the
physical system levels of ICS have the highest severity once cyberattacked, and
controllers, workstations, and human-machine interface are the crucial
components in the cyberattack and defense.
