CRISC Risk Response and Reporting Practice Question
Which of the following is the BEST Key Control Indicator (KCI) for measuring the effectiveness of a firewall?
⚠ Common exam trap
Many candidates confuse operational metrics (like patch age or change volume) with direct effectiveness metrics, leading candidates to choose a maintenance or activity indicator instead of a performance-based KCI.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Percentage of blocked intrusion attempts
The percentage of blocked intrusion attempts directly measures how effectively the firewall is enforcing its security policies to prevent unauthorized access. A high block rate indicates the firewall is correctly identifying and stopping threats, making it the most direct KCI for firewall effectiveness.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Percentage of blocked intrusion attempts
Why this is correct
This directly measures how well the firewall is performing its preventive function.
- ✗
Time since last firewall firmware update
Why it's wrong here
This indicates maintenance, not effectiveness in blocking threats.
- ✗
Number of firewall rule changes per month
Why it's wrong here
This measures change activity, not control effectiveness.
- ✗
Number of firewall alerts generated
Why it's wrong here
Alerts could be false positives; blocked attempts are a better measure.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CRISC practice question is part of Courseiva's free ISACA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CRISC exam.