Security audits and assessments: internal, external, penetration test, vulnerability assessment

CompTIA Security+ Preparation · lesson 40 of 45 · 25 min

Types of Security Assessments

Vulnerability assessment — identifies and prioritizes vulnerabilities. Does NOT exploit them. Automated scanning + manual review. Output: prioritized list of vulnerabilities with CVSS scores.

Penetration test — actively exploits vulnerabilities to demonstrate real impact. Authorized simulated attack. Output: findings with proof-of-concept exploits and remediation recommendations.

Security audit — systematic evaluation of security controls against a standard or policy. Checks compliance. Can be internal (self-assessment) or external (third-party). Output: audit report with findings and compliance status.

Risk assessment — identifies threats, vulnerabilities, and their potential business impact. Quantitative (dollar values) or qualitative (High/Medium/Low). Output: risk register with prioritized risks.

Red team exercise — full-scope adversary simulation. Red team (attackers) vs Blue team (defenders). Tests people, processes, and technology. More comprehensive than a pen test.

Purple team — red and blue teams work together. Red team attacks while blue team observes and improves detections in real time.

Audit Standards and Compliance

SOC 2 — Service Organization Control 2. Audits cloud service providers on Trust Service Criteria: Security, Availability, Processing Integrity, Confidentiality, Privacy. Type 1: point-in-time. Type 2: over a period (6–12 months).

ISO 27001 — international standard for Information Security Management Systems (ISMS). Certification requires implementing controls from Annex A and passing an external audit.

PCI-DSS — Payment Card Industry Data Security Standard. Required for organizations that process, store, or transmit cardholder data. Annual assessment by a Qualified Security Assessor (QSA).

HIPAA Security Rule — requires healthcare organizations to implement administrative, physical, and technical safeguards for electronic Protected Health Information (ePHI).

Key Terms

Key Terms

Knowledge Check — 10 Questions

Security+ — Security Audits & Assessments

A vulnerability assessment differs from a penetration test because:

  • Vulnerability assessments are more expensive
  • Vulnerability assessments identify vulnerabilities without exploiting them
  • Penetration tests are automated
  • They are identical
  • Answer: Vulnerability assessments identify vulnerabilities without exploiting them

Vulnerability assessments find and prioritize vulnerabilities. Pen tests actively exploit them to demonstrate real impact. A red team exercise tests:

  • Only technical controls
  • People, processes, and technology through full adversary simulation
  • Only network security
  • Only application security
  • Answer: People, processes, and technology through full adversary simulation

Red team exercises are comprehensive — they test the entire security program, including human responses and detection capabilities. SOC 2 Type 2 differs from Type 1 because:

  • Type 2 is more expensive
  • Type 2 evaluates controls over a period (6–12 months); Type 1 is point-in-time
  • Type 1 is more rigorous
  • They cover different industries
  • Answer: Type 2 evaluates controls over a period (6–12 months); Type 1 is point-in-time

SOC 2 Type 2 is more valuable — it demonstrates that controls were operating effectively over time, not just at one moment. PCI-DSS applies to organizations that:

  • Use cloud services
  • Process, store, or transmit cardholder data
  • Have more than 100 employees
  • Operate in the US only
  • Answer: Process, store, or transmit cardholder data

PCI-DSS applies to any organization that handles payment card data — regardless of size or location. A purple team exercise involves:

  • Red team attacking without blue team knowledge
  • Red and blue teams working together to improve detections in real time
  • Only blue team defensive exercises
  • External auditors only
  • Answer: Red and blue teams working together to improve detections in real time

Purple teaming is collaborative — red attacks while blue observes, improving detection rules and response procedures together. ISO 27001 certification requires:

  • Only a self-assessment
  • Implementing ISMS controls and passing an external audit
  • Only technical controls
  • Annual penetration testing
  • Answer: Implementing ISMS controls and passing an external audit

ISO 27001 certification requires implementing an ISMS with Annex A controls and passing a formal external audit by an accredited body. A risk assessment output is:

  • A list of open ports
  • A risk register with prioritized risks and their business impact
  • A list of CVEs
  • A compliance checklist
  • Answer: A risk register with prioritized risks and their business impact

Risk assessments produce a risk register — threats, vulnerabilities, likelihood, impact, and risk treatment decisions. HIPAA Security Rule protects:

  • Payment card data
  • Electronic Protected Health Information (ePHI)
  • Government classified data
  • Financial records
  • Answer: Electronic Protected Health Information (ePHI)

HIPAA Security Rule requires healthcare organizations to protect ePHI through administrative, physical, and technical safeguards. An internal security audit is conducted by:

  • External auditors only
  • The organization’s own security team (self-assessment)
  • Government regulators
  • Customers
  • Answer: The organization’s own security team (self-assessment)

Internal audits are self-assessments — valuable for continuous improvement. External audits provide independent verification.

A QSA (Qualified Security Assessor) conducts _____ assessments.

Answer: PCI-DSS
QSAs are certified by the PCI Security Standards Council to conduct formal PCI-DSS compliance assessments.


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