Question 46 of 509
Attacks and ExploitsmediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is to use the '!' command within 'less' to execute a shell. This technique works because when a binary like less is run with sudo, it inherits root-level permissions, and less includes a built-in escape feature that allows users to run shell commands by typing an exclamation mark followed by a command. Since the low-privileged user can execute less as root without a password, entering `!/bin/bash` inside the pager spawns a root shell, achieving privilege escalation. On the CompTIA PenTest+ PT0-002 exam, this scenario tests your understanding of sudo misconfigurations and the GTFOBins concept, where common binaries can be abused for privilege escalation. A common trap is forgetting that less retains its interactive shell feature even when run with elevated privileges. Memory tip: think "Less is more—exclamation mark opens the door."

PT0-002 Attacks and Exploits Practice Question

This PT0-002 practice question tests your understanding of attacks and exploits. 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 has gained a shell on a Linux machine as a low-privileged user. The user can execute the binary 'less' with sudo privileges without a password. Which technique can the tester use to escalate privileges to root?

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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

Use the '!' command within 'less' to execute a shell.

The 'less' binary, when executed with sudo, retains its ability to spawn a shell via the '!' command. Since the user can run 'less' as root without a password, typing '!/bin/bash' (or simply '!bash') inside 'less' will execute a shell with root privileges, effectively escalating to root.

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.

  • Exploit a buffer overflow in the 'less' binary.

    Why it's wrong here

    While buffer overflows could theoretically be exploited, this is not the most direct method given the sudo privilege. The '!' command provides immediate command execution without memory corruption.

  • Use the '!' command within 'less' to execute a shell.

    Why this is correct

    Correct. The '!' command in less allows execution of shell commands. With sudo, this runs as root, granting privilege escalation.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Run 'sudo -u root bash' to switch to a root shell.

    Why it's wrong here

    The sudoers rule only allows 'less' specifically. Running 'sudo -u root bash' would prompt for a password or be denied because the rule is not general.

  • Modify the PATH to trick sudo into running a malicious binary.

    Why it's wrong here

    PATH manipulation is not effective when the binary path is explicitly specified in sudoers (i.e., using the full path). Additionally, 'less' is typically at a fixed location.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may overlook the shell escape feature of pagers like 'less' and instead assume they need to exploit a binary vulnerability or use a generic 'sudo -u root bash' command, which fails because the sudoers rule is specific to 'less' only.

Trap categories for this question

  • Command / output trap

    While buffer overflows could theoretically be exploited, this is not the most direct method given the sudo privilege. The '!' command provides immediate command execution without memory corruption.

Detailed technical explanation

How to think about this question

The 'less' pager, like 'more' and 'vim', can execute shell commands when invoked with the '!' prefix. This feature is often enabled by default and is a classic sudo privilege escalation technique when a user is allowed to run 'less' as root. In real-world assessments, testers check for such misconfigurations using 'sudo -l' to list permitted commands, then leverage the pager's shell escape to gain a root shell.

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 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.

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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FAQ

Questions learners often ask

What does this PT0-002 question test?

Attacks and Exploits — This question tests Attacks and Exploits — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Use the '!' command within 'less' to execute a shell. — The 'less' binary, when executed with sudo, retains its ability to spawn a shell via the '!' command. Since the user can run 'less' as root without a password, typing '!/bin/bash' (or simply '!bash') inside 'less' will execute a shell with root privileges, effectively escalating to root.

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.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 11, 2026

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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.