PT0-003 CompTIA Exam Lab Questions

DIR_MODE=0777 configures new home directories to be created world-readable, world-writable, and world-executable (rwxrwxrwx). With such permissive permissions, any unprivileged local user can traverse into other users’ home directories, list files, read them, and even modify or replace them. That makes exposure of other users’ sensitive data the most likely and immediate outcome once the tester has any local user account.

Why the other options are less likely:

B. Unauthorized sudo execution: Requires membership in sudo/wheel or explicit entries in /etc/sudoers. Nothing in the snippet indicates that, and file mode on home dirs doesn’t grant sudo.

C. Hijacking default login shells: DSHELL=/bin/zsh only sets the default shell for new users. Replacing /bin/zsh or altering /etc/passwd would require root.

D. Corrupting the skeleton configuration: SKEL=/etc/systemd-conf/temp-skeleton is under /etc/…, which is root-owned on standard systems. A normal user cannot write there, so “corrupting the skeleton” is unlikely without privilege escalation.

Practical exploitation as a non-privileged user (illustrative):

# Find world-writable homes

find /home -maxdepth 1 -type d -perm -0002 -ls

# Read another user's files

cd /home/targetuser && ls -la && cat Documents/tax_return.pdf

(Depending on per-file permissions.)

CompTIA PenTest+ PT0-003 Objective Mapping (for study):

Domain 3.0 Attacks and Exploits

3.1 Exploit system vulnerabilities and misconfigurations (e.g., insecure file permissions leading to data exposure/privilege abuse).

The attack narrative is a critical part of the report that tells the story of how the tester exploited vulnerabilities, gained access, and moved laterally. It helps stakeholders understand the real-world impact in a readable and logical sequence.

User activities are more operational logs than part of a pentest report.

Customer remediation plan is the client’s responsibility.

Key management might be discussed but is not a required component of the report.

An external attack surface review focuses on identifying publicly accessible assets that an attacker could exploit. The first step in this process is information gathering, which involves enumerating domains, subdomains, public IPs, DNS records, and other internet-facing resources. This is done using passive reconnaissance tools such as Whois, Shodan, Google Dorking, and OSINT techniques.

Option A is correct because it aligns with the assessment goal—finding public-facing systems and their vulnerabilities before an attacker does.

Option B (phishing assessment) is incorrect because it involves social engineering, which is not part of an external attack surface review.

Option C (physical security review) is incorrect as it pertains to physical penetration testing, not an external attack analysis.

Option D (vulnerability assessment) is incorrect because a vulnerability assessment is a later step after reconnaissance. The first step is identifying assets through information gathering.

A false positive occurs when a vulnerability scan incorrectly flags a security issue that does not exist or is not exploitable in the context of the application. Here's the reasoning:

Definition of Command Injection:Command injection vulnerabilities occur when user-controllable data is passed to an interpreter or command execution context without proper sanitization, allowing an attacker to execute arbitrary commands.

Code Analysis:

The response variable is defined as a constant (const), which implies its value is immutable during runtime.

The response is not sourced from user input nor used elsewhere, meaning there is no attack surface or exploitation pathway for an attacker to influence the content of response.

Scanner Misclassification:Static Application Security Testing (SAST) tools may flag vulnerabilities based on patterns (e.g., .innerHTML usage) without assessing the source and flow of data, resulting in false positives.

Final Classification:Since the response variable is static and unchangeable, the flagged issue is not exploitable. This makes it a false positive.

CompTIA Pentest+ References:

Domain 3.0 (Attacks and Exploits)

Domain 4.0 (Penetration Testing Tools)

OWASP Static Code Analysis Guide