CISA Protection of Information Assets Practice Question
During an audit of a public key infrastructure (PKI), the IS auditor finds that certificate revocation lists (CRLs) are only updated weekly. Which of the following is the MOST significant risk?
⚠ Common exam trap
CISA often tests the difference between availability/performance impacts and security impacts; candidates may pick network traffic or validation delays because they sound like consequences of large CRLs, but the most significant risk is that revoked certificates remain trusted.
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
✓
Revoked certificates may be accepted as valid
If CRLs are only updated weekly, revoked certificates may still be accepted as valid during the interval between revocation and CRL publication, allowing compromised or misused certificates to be trusted. This is the most significant risk because it undermines the revocation mechanism and can enable impersonation or man-in-the-middle attacks. Timely revocation is critical to PKI trust.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Certificate authorities may become unavailable
Why it's wrong here
Weekly CRLs leave a window in which a revoked certificate still validates, so compromised keys remain usable for days. Auditors often flag CRL latency as a freshness control, but CA availability depends on redundancy and capacity, not on how frequently revocation data is republished.
- ✓
Revoked certificates may be accepted as valid
Why this is correct
Weekly CRL publication creates a window in which a revoked certificate remains absent from the list, so relying parties continue to treat it as valid. Until the next update, compromised or misissued certificates can still authenticate, undermining the PKI's revocation assurance.
- ✗
Increased network traffic due to large CRLs
Why it's wrong here
CRL size is driven by the number of revoked certificates, not the publication interval, so weekly updates do not inflate traffic. It is tempting because large CRLs genuinely strain bandwidth and client download times, which is why delta CRLs and OCSP exist, but that is not the risk here.
- ✗
Users may experience delays in certificate validation
Why it's wrong here
Weekly CRL publication leaves a window in which a revoked certificate still validates, so a compromised or rogue key remains usable for up to seven days. Delays in validation affect performance, not security, and would matter only where latency is the audit concern — not where revocation timeliness is.
Go deeper
Related to this question
About these practice questions
This CISA question is part of Courseiva's 934-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISACA exam blueprint
This CISA 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 CISA exam.