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Best Practices for Securing Containerized Applications
Which TWO of the following are best practices for securing containerized applications? (Select exactly 2.)
Quick Answer
The answer is using minimal base images such as Alpine or scratch and running containers as a non-root user. These two practices directly reduce the attack surface and limit the potential for container breakout, which is a core concern in container security best practices. A minimal base image eliminates unnecessary packages and libraries that could harbor vulnerabilities, while running as non-root ensures that even if an attacker compromises the container, they lack the privileges to escalate to the host system. On the CISSP exam, this topic appears in Domain 3 (Security Architecture and Engineering) and tests your understanding of secure configuration and isolation mechanisms. A common trap is confusing production hardening with debugging convenience—options like enabling debug ports or bind mounting the host filesystem are dangerously insecure. For a quick memory tip, think “lean and low”: keep the image lean (minimal base) and the user low (non-root).
⚠ Common exam trap
A common mix-up: candidates confuse 'persisting logs' (Option A) as a security measure, but in container security, mounting the host filesystem is a major isolation violation, not a best practice.
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
✓
Running the container process as a non-root user
Running the container process as a non-root user is a fundamental security best practice because containers share the host kernel; if an attacker compromises a container running as root, they may escape to the host with root privileges. By using a non-root user (e.g., via the USER directive in a Dockerfile), you enforce the principle of least privilege and reduce the attack surface significantly.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Mounting the host filesystem to persist logs
Why it's wrong here
Mounting the host root filesystem gives container access to all host resources.
- ✓
Running the container process as a non-root user
Why this is correct
Non-root user reduces privilege escalation risk.
- ✗
Cleaning the certificate store to prevent MITM
Why it's wrong here
Certificate store removal breaks HTTPS; instead, update certificates.
- ✗
Exposing port 22 for SSH debugging in production
Why it's wrong here
SSH is not recommended; use exec commands instead.
- ✓
Using minimal base images such as Alpine or scratch
Why this is correct
Minimal images reduce the attack surface.
Go deeper
Related to this question
Learn chapter
Security Governance and Principles
Key term
Access control
Access control is the security practice of determining who or what is allowed to view, use, or enter a resource, and under what conditions.
Key term
Security
Security in IT is the practice of protecting systems, networks, and data from unauthorized access, damage, or theft.
About these practice questions
Courseiva writes every CISSP question from scratch — 747 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on CISSP
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. A company is deploying a containerized application using Kubernetes. Which practice BEST ensures the security of the container images?
medium- ✓ A.Scan images for vulnerabilities and use minimal base images
- B.Restrict containers from running as root
- C.Use the latest version of the base image without scanning
- D.Enable container escape protection
Why A: Scanning container images for known vulnerabilities (e.g., using Trivy, Clair, or Snyk) and using minimal base images (e.g., Alpine or distroless) directly reduces the attack surface and eliminates unnecessary packages that may contain exploitable flaws. This practice is foundational to secure software supply chain management and aligns with the principle of least functionality in containerized environments.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CISSP practice question is part of Courseiva's free ISC2 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 CISSP exam.