The answer is local file inclusion (LFI). This Bash script testing for local file inclusion in a pentest uses curl to send HTTP requests with payloads and then checks the response for the string "root:x:0:0", which is the exact format of the root user entry in the /etc/passwd file on Unix-like systems. If the server returns that string, it confirms the script successfully forced the server to read and output a local file, a classic indicator of an LFI or path traversal vulnerability. On the CompTIA PenTest+ PT0-002 exam, this scenario tests your ability to recognize how automated scripts validate file inclusion flaws by looking for known system file contents rather than just error messages. A common trap is confusing this with command injection, but the key clue is the specific file content check. Memory tip: if you see "root:x:0:0" in a response, think "LFI reads the passwd file."
PT0-002 Tools and Code Analysis Practice Question
This PT0-002 practice question tests your understanding of tools and code analysis. 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 penetration tester is analyzing a Bash script that uses 'curl' to send HTTP requests with payloads and checks for a specific string in the response. The script contains: 'if echo $response | grep -q "root:x:0:0"'. Which vulnerability is the script most likely testing for?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Why wrong: SQL injection attacks aim to extract database content, not read system files like /etc/passwd.
B
Local file inclusion
The script is attempting to read the /etc/passwd file via a file inclusion vulnerability, which would return the password file content containing the 'root:x:0:0' line.
C
Cross-site scripting
Why wrong: XSS testing would typically look for script execution or reflected payload in the response, not system file contents.
D
Remote code execution
Why wrong: RCE testing would aim to execute commands and observe their output, not read a static file like /etc/passwd.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Local file inclusion
The script checks for the string 'root:x:0:0' in the HTTP response, which is the standard format of the root user entry in the /etc/passwd file on Unix-like systems. This indicates the script is testing whether the server is returning the contents of a local file (e.g., /etc/passwd) via a path traversal or file inclusion vulnerability, making Local File Inclusion (LFI) the correct answer.
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.
✗
SQL injection
Why it's wrong here
SQL injection attacks aim to extract database content, not read system files like /etc/passwd.
✓
Local file inclusion
Why this is correct
The script is attempting to read the /etc/passwd file via a file inclusion vulnerability, which would return the password file content containing the 'root:x:0:0' line.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Cross-site scripting
Why it's wrong here
XSS testing would typically look for script execution or reflected payload in the response, not system file contents.
✗
Remote code execution
Why it's wrong here
RCE testing would aim to execute commands and observe their output, not read a static file like /etc/passwd.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may confuse the presence of a specific string in the response with SQL injection (e.g., thinking 'root:x:0:0' is a database record), but the format is a direct match for the /etc/passwd file, which is a classic LFI indicator.
Trap categories for this question
Command / output trap
RCE testing would aim to execute commands and observe their output, not read a static file like /etc/passwd.
Detailed technical explanation
How to think about this question
The string 'root:x:0:0' is the first line of /etc/passwd, where 'x' indicates the password is stored in /etc/shadow, and the two zeros represent the user ID (UID) and group ID (GID) of the root user. In an LFI attack, a penetration tester might use a payload like '?file=../../etc/passwd' to read sensitive system files, and curl with grep confirms successful retrieval by matching this known pattern.
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 developer is choosing between AES-256 (symmetric) and RSA-2048 (asymmetric) for encrypting a large file that will be sent to a partner. Symmetric encryption is fast but requires key exchange; asymmetric is slower but solves the key distribution problem. A hybrid approach — encrypt the file with AES, encrypt the AES key with RSA — is standard. Questions like this test whether you understand when each approach applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this PT0-002 question in full detail.
Tools and Code Analysis — This question tests Tools and Code Analysis — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Local file inclusion — The script checks for the string 'root:x:0:0' in the HTTP response, which is the standard format of the root user entry in the /etc/passwd file on Unix-like systems. This indicates the script is testing whether the server is returning the contents of a local file (e.g., /etc/passwd) via a path traversal or file inclusion vulnerability, making Local File Inclusion (LFI) the correct answer.
What should I do if I get this PT0-002 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: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 PT0-002 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 PT0-002 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.