The answer is directory traversal. This vulnerability, also known as path traversal, is exploited when an attacker manipulates variables that reference files with “dot-dot-slash” (../) sequences, like changing the file parameter to ../../etc/passwd, to break out of the web root and access sensitive system files. On the Certified Ethical Hacker CEH exam, this scenario tests your ability to identify input validation flaws in web applications, often appearing in the web application penetration testing domain. A common trap is confusing directory traversal with command injection—remember, traversal uses file paths, not system commands. A useful memory tip: think of the “../” as a ladder climbing out of the web folder, and if the application doesn’t sanitize that ladder, it’s a traversal.
CEH Web Application and Injection Attacks Practice Question
This CEH practice question tests your understanding of web application and injection attacks. 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 web application allows users to view documents by specifying a filename in the URL, e.g., /getDocument?file=report.pdf. A tester changes the file parameter to '../../etc/passwd' and retrieves the system password file. Which vulnerability is being exploited?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Directory traversal
Directory traversal (path traversal) occurs when user input is used to access files outside the intended directory. The use of '../' sequences indicates directory traversal.
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.
✗
Local File Inclusion (LFI)
Why it's wrong here
LFI typically includes files for execution, not just reading; directory traversal is the core technique.
✓
Directory traversal
Why this is correct
Directory traversal exploits insufficient input validation to access arbitrary files.
Related concept
Static NAT maps one inside address to one outside address.
✗
Remote File Inclusion (RFI)
Why it's wrong here
RFI involves including remote files, not local traversal.
✗
Command injection
Why it's wrong here
Command injection involves injecting OS commands, not file path traversal.
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.
Trap categories for this question
Command / output trap
Command injection involves injecting OS commands, not file path traversal.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CEH question in full detail.
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 CEH NAT questions on configuration and troubleshooting.
Web Application and Injection Attacks — This question tests Web Application and Injection Attacks — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Directory traversal — Directory traversal (path traversal) occurs when user input is used to access files outside the intended directory. The use of '../' sequences indicates directory traversal.
What should I do if I get this CEH 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 CEH 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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. While analyzing web server logs, an analyst finds the following entry: GET /../../../../etc/passwd HTTP/1.1 with a 200 OK response. Which vulnerability is indicated, and what is the MOST likely impact?
Why B: The path contains '../' sequences indicating directory traversal. A 200 response suggests the attacker successfully read the /etc/passwd file, leading to disclosure of system user accounts. This can aid further attacks like password cracking.
Last reviewed: Jun 21, 2026
Question Discussion
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This CEH practice question is part of Courseiva's free EC-Council 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 CEH exam.
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