The correct answer is that without salting, the hashes are vulnerable to precomputed rainbow table attacks. MD5 is a fast, deterministic hash function, meaning the same password always produces the same hash; an attacker can precompute a massive table of common passwords and their MD5 hashes, then instantly reverse any unsalted hash by looking it up. This is the primary concern because the lack of salt removes the only defense against such precomputation, making even complex passwords trivial to crack if they appear in the table. On the ISC2 CC exam, this question tests your understanding that hashing is one-way but not secure without salt—a common trap is confusing speed with strength, when in fact MD5’s speed is a vulnerability, not an asset. Remember the mnemonic: “No salt, no safety—rainbow tables make unsalted MD5 a plaintext playground.”
ISC2 CC Security Principles Practice Question
This CC practice question tests your understanding of security principles. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
During a security audit, you discover that a financial application stores passwords using MD5 hashing without salt. What is the primary security concern with this practice?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "primary"
Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Without salting, the hashes are vulnerable to precomputed rainbow table attacks
Option B is correct because MD5 is vulnerable to rainbow table attacks, and lack of salting makes it easy for attackers to precompute hashes. Reversibility is not the primary concern (hashing is one-way). Speed is actually a vulnerability, not a strength. Compliance violation is a secondary issue.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
MD5 is reversible, allowing attackers to recover plaintext passwords
Why it's wrong here
MD5 is a one-way hash; it is not reversible, but it is cryptographically broken.
✗
MD5 is too slow, causing performance issues during authentication
Why it's wrong here
MD5 is fast, which is actually a weakness for password storage, not a strength.
✓
Without salting, the hashes are vulnerable to precomputed rainbow table attacks
Why this is correct
Rainbow tables can quickly find matching plaintext for unsalted MD5 hashes.
Clue confirmation
The clue word "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Storing hashes violates PCI DSS compliance, but does not affect security
Why it's wrong here
It does affect security; PCI DSS requires strong cryptography and salting.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A security team runs a vulnerability scan on a web application and discovers an unpatched SQL injection flaw. The team prioritises remediation by CVSS score — critical flaws are patched within 24 hours, high within 7 days. Questions like this test whether you understand vulnerability management processes, scanning tools, and remediation prioritisation.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CC question in full detail.
Identify which CC exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Security Principles — This question tests Security Principles — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Without salting, the hashes are vulnerable to precomputed rainbow table attacks — Option B is correct because MD5 is vulnerable to rainbow table attacks, and lack of salting makes it easy for attackers to precompute hashes. Reversibility is not the primary concern (hashing is one-way). Speed is actually a vulnerability, not a strength. Compliance violation is a secondary issue.
What should I do if I get this CC question wrong?
Identify which CC exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This CC practice question is part of Courseiva's free ISC2 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 CC exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.