- A
Deploy a Web Application Firewall (WAF) in front of the web server to filter malicious SQL patterns
A WAF can provide virtual patching without code changes, blocking SQL injection attempts.
- B
Implement network segmentation to isolate the web server from the database server
Why wrong: Segmentation reduces the impact but does not prevent SQL injection attacks from reaching the database.
- C
Apply input validation on the web server by configuring the web server itself to sanitize inputs
Why wrong: Input validation requires application-level changes; web servers typically do not have built-in input validation for application logic.
- D
Apply the latest security patches to the web server operating system
Why wrong: OS patches do not fix application-level vulnerabilities like SQL injection.
200-901 Application Deployment and Security Practice Question
This 200-901 practice question tests your understanding of application deployment and security. 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.
A financial services company deploys a multi-tier application on Cisco UCS with separate VMs for web, app, and database tiers. The security team runs a vulnerability scan and finds that the web server is vulnerable to SQL injection. The development team cannot fix the code immediately because of a pending third-party library update. The company needs to deploy a security control to mitigate the vulnerability as soon as possible without changing the application. Which of the following is the best immediate mitigation?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Clue:
"immediately / without restart"Why it matters: Time or reboot constraint — the correct answer must take effect right away without requiring a reboot or reload.
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
Deploy a Web Application Firewall (WAF) in front of the web server to filter malicious SQL patterns
A Web Application Firewall (WAF) operates at Layer 7 and can inspect HTTP/HTTPS traffic for malicious payloads, such as SQL injection patterns, without requiring any changes to the application code. By deploying a WAF in front of the web server, the company can immediately filter out malicious SQL patterns (e.g., ' OR 1=1 --) using signature-based or behavioral rules, providing a virtual patch until the code fix is available. This aligns with the requirement to mitigate the vulnerability without modifying the application itself.
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.
- ✓
Deploy a Web Application Firewall (WAF) in front of the web server to filter malicious SQL patterns
Why this is correct
A WAF can provide virtual patching without code changes, blocking SQL injection attempts.
Clue confirmation
The clue words "best", "immediately / without restart" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Implement network segmentation to isolate the web server from the database server
Why it's wrong here
Segmentation reduces the impact but does not prevent SQL injection attacks from reaching the database.
- ✗
Apply input validation on the web server by configuring the web server itself to sanitize inputs
Why it's wrong here
Input validation requires application-level changes; web servers typically do not have built-in input validation for application logic.
- ✗
Apply the latest security patches to the web server operating system
Why it's wrong here
OS patches do not fix application-level vulnerabilities like SQL injection.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the distinction between network-layer controls (like segmentation) and application-layer controls (like WAF), trapping candidates who think isolating the database server stops SQL injection, when in fact the malicious SQL commands are generated by the web server itself after the attack has already succeeded.
Detailed technical explanation
How to think about this question
A WAF can be deployed as a reverse proxy or inline device, inspecting HTTP request parameters, headers, and cookies for SQL injection signatures using regular expressions or machine learning models. In a Cisco UCS environment, a virtual WAF (e.g., Cisco Firepower NGIPS with WAF capabilities) can be integrated into the traffic flow without physical hardware changes. Real-world scenarios often involve WAFs providing 'virtual patching' for zero-day vulnerabilities, allowing organizations to comply with PCI DSS requirements while awaiting vendor patches.
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.
TExam Day Tips
- 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 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.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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Learn the concepts, then practise the questions
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FAQ
Questions learners often ask
What does this 200-901 question test?
Application Deployment and Security — This question tests Application Deployment and Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Deploy a Web Application Firewall (WAF) in front of the web server to filter malicious SQL patterns — A Web Application Firewall (WAF) operates at Layer 7 and can inspect HTTP/HTTPS traffic for malicious payloads, such as SQL injection patterns, without requiring any changes to the application code. By deploying a WAF in front of the web server, the company can immediately filter out malicious SQL patterns (e.g., ' OR 1=1 --) using signature-based or behavioral rules, providing a virtual patch until the code fix is available. This aligns with the requirement to mitigate the vulnerability without modifying the application itself.
What should I do if I get this 200-901 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best", "immediately / without restart". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jun 24, 2026
This 200-901 practice question is part of Courseiva's free Cisco 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 200-901 exam.
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