iSACA Cybersecurity Fundamentals Certification Practice Exam

What is a significant weakness of Intrusion Detection Systems?

1. Inability to block attacks

2. Excessive processing power usage

3. Can only detect internal threats

4. Requires constant user interaction

The correct answer is: Inability to block attacks

The significant weakness of Intrusion Detection Systems (IDS) is indeed their inability to block attacks. IDS are designed primarily to monitor and analyze network traffic for suspicious activities or policy violations. When a potential threat is detected, the IDS generates alerts or logs the event but does not have the capability to take preventive actions. This limitation can leave an organization's systems vulnerable if an identified threat is not mitigated in a timely manner through other means, such as firewalls or response teams. The other choices refer to aspects that are often not as critical to the primary function of IDS. For example, while excessive processing power usage can occur, many modern systems are optimized to handle data efficiently. Similarly, the notion that IDS can only detect internal threats is misleading. They are indeed capable of detecting external threats as well. Lastly, the requirement for constant user interaction is not a typical feature of IDS; they are designed to operate autonomously after initial setup, monitoring the network continuously without the need for ongoing user intervention. Thus, the inherent limitation of IDS is their passive nature in detecting threats rather than actively preventing them.