The answer is SQL injection and cross-site scripting (XSS). A web application firewall (WAF) most effectively prevents these two attacks because they operate at the application layer, where a WAF inspects HTTP traffic for malicious payloads using signature-based detection and heuristic analysis. SQL injection attempts to manipulate database queries through user input, while XSS injects client-side scripts into web pages; both can be blocked by a WAF before they reach the application server. On the CompTIA SecurityX CAS-004 exam, this question tests your understanding of WAF capabilities versus other controls—a common trap is confusing cross-site request forgery (CSRF) with XSS, but CSRF requires anti-forgery tokens that a WAF cannot enforce, and session hijacking is typically mitigated at the network layer. Remember the memory tip: "WAFs love the web layer—SQL and XSS are their prey; tokens and sessions are not their way."
CAS-004 Security Engineering Practice Question
This CAS-004 practice question tests your understanding of security engineering. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
A security architect is evaluating web application firewall (WAF) features to protect against common attacks. Which TWO of the following attacks can a WAF most effectively prevent?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Cross-site scripting (XSS)
SQL injection and XSS are application-layer attacks that a WAF can detect and block based on signatures or heuristics. CSRF requires tokens, and session hijacking is often at the network layer.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
Static NAT maps one inside address to one outside address.
✓
SQL injection
Why this is correct
WAFs can filter malicious SQL patterns.
Related concept
Static NAT maps one inside address to one outside address.
✗
Distributed denial-of-service (DDoS)
Why it's wrong here
DDoS mitigation often requires dedicated DDoS protection services.
✗
Cross-site request forgery (CSRF)
Why it's wrong here
CSRF is best mitigated by anti-CSRF tokens; WAFs are not effective.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related CAS-004 NAT questions on configuration and troubleshooting.
Security Engineering — This question tests Security Engineering — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Cross-site scripting (XSS) — SQL injection and XSS are application-layer attacks that a WAF can detect and block based on signatures or heuristics. CSRF requires tokens, and session hijacking is often at the network layer.
What should I do if I get this CAS-004 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related CAS-004 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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 CAS-004 practice question is part of Courseiva's free CompTIA 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 CAS-004 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.