Certified Information Systems Security Professional (CISSP) Practice Exam

A countermeasure is accurately defined as a control implemented to prevent the exploitation of vulnerabilities. In the realm of information security, countermeasures are proactive actions or tools that are used to mitigate risks associated with identified threats and vulnerabilities. They are designed to reduce the likelihood of a security incident occurring, and can include a variety of strategies such as implementing firewalls, encryption, access controls, security patches, and intrusion detection systems.

Effective countermeasures not only aim to prevent attacks but can also mitigate their impact should they occur. By understanding and deploying countermeasures, organizations can better protect their information assets and ensure compliance with security policies and standards.

In contrast, other definitions do not capture the essence of countermeasures. Assessing risks relates to risk management processes, malware pertains to malicious software that intends to harm or exploit systems, and legal restrictions govern the use of information but do not serve the practical purpose of preventing security threats.