Pentest & Security Auditing

As a penetration tester, it is essential to understand the when, how, and why of security audits and their relationship to penetration testing.

Security audits and penetration testing are distinct assessments with unique objectives, scopes, and outcomes. Security audits evaluate an organization’s overall security posture, focusing on compliance, policies, and controls, while penetration testing is more targeted, aiming to identify and exploit vulnerabilities in a system.

• Audits are often conducted first to assess compliance and controls.

• Penetration testing follows to simulate real-world attacks, testing the effectiveness of the controls in practice.

In some cases, audits and penetration testing may be combined, but they generally serve different purposes and are performed sequentially for a comprehensive assessment.

Differences

Differences	Security Audit	Penetration Test
Purpose	Evaluate overall security posture, compliance, and controls.	Identify and exploit vulnerabilities in specific systems.
Scope	Broad; includes policies, procedures, and technical controls.	Narrow; focused on specific applications, networks, or systems.
Methodology	Systematic review of documentation, interviews, and assessments.	Simulated attacks using various tools and techniques to exploit vulnerabilities.
Outcome	Comprehensive report on security posture, compliance status, and recommendations for improvement.	Detailed findings of vulnerabilities, exploitation techniques, and remediation steps.
Frequency	Conducted periodically (e.g., annually, biannually) or as required for compliance.	Performed as needed (e.g., after major changes, before product launches, or periodically to ensure ongoing security).

Approach to Security Assessments

Organizations typically choose between two approaches: sequential and combined. Most commonly, organizations adopt the sequential approach.

Sequential Approach

Perform Security Audit First: Companies conduct a security audit initially to evaluate their overall security posture, ensure compliance with regulations, and identify areas for improvement in policies and procedures.

Conduct Penetration Test Afterwards: Following the audit, a penetration test is carried out based on the audit findings to assess the effectiveness of technical controls and identify specific vulnerabilities.

Advantages

• Provides a comprehensive view of security from both policy and technical perspectives.

• Identifies and addresses gaps in procedural and technical controls.

• Helps prioritize remediation efforts based on audit findings.

Example

Context: SecurePayments Inc. is a fictional organization that processes credit card transactions and must adhere to PCI DSS standards. They are using a sequential approach to assess their overall security posture.

Security Audit

Audit Completion: SecurePayments Inc. has performed a security audit through an independent audit firm and is using the findings in the audit report as the basis of their remediation efforts.

Key Findings

• Inadequate encryption for cardholder data in transit.

• Weak/inadequate network security controls and traffic monitoring.

• Weak access control policies allowing excessive permissions.

• Outdated incident response procedures.

• Corresponding Recommendations:

  • Implement strong encryption protocols for data in transit.

  • Revise access control policies to follow the principle of least privilege.

  • Update and test incident response procedures regularly.

SecurePayments Inc. followed the security auditing lifecycle and made the necessary improvements based on these recommendations.

Penetration Test

Objectives: After making the necessary changes based on the audit findings, SecurePayments Inc. has hired you (or your firm) to test the technical controls and security measures implemented to verify their effectiveness.

Phase 1: Planning and Preparation

• Scope Definition: Identify that the PCI DSS scope includes the cardholder data environment (CDE).

• Documentation Review: Review SecurePayments Inc.’s network diagrams and PCI DSS self-assessment questionnaires to understand current security measures and compliance status.

• Objectives:

  • Define the scope of the penetration test to focus on areas identified in the audit, such as network security and application vulnerabilities.

  • Set up a testing schedule and inform stakeholders.

Phase 2: Information Gathering and Reconnaissance

• Gather information on SecurePayments Inc.'s security policies, including access control policies, encryption standards, and incident response procedures.

• Review the most recent PCI DSS audit report to identify areas of concern highlighted by auditors.

Phase 3: Penetration Test Execution

• Conduct network scanning, enumeration, and vulnerability assessments to identify weaknesses, misconfigurations, or vulnerabilities.

• Attempt exploitation of identified vulnerabilities to assess their impact.

• Test the effectiveness of newly implemented encryption and access controls.

Phase 4: Findings and Recommendations

Outcome: The penetration test uncovers additional vulnerabilities:

• An exposed administrative interface that allows unauthorized access.

• SQL injection vulnerabilities in a customer-facing web application.

Recommendations

• Secure the administrative interface by implementing additional authentication and access controls.

• Patch the SQL injection vulnerabilities and conduct a thorough review of application security.

Summary of Sequential Approach

Security Audit Results

• Identified compliance gaps and policy deficiencies.

• Provided recommendations for improving security policies and procedures.

Penetration Testing Results

• Revealed specific technical vulnerabilities.

• Offered targeted recommendations to address these technical weaknesses.

Combined Approach

Integrate Security Audit and Penetration Testing: Some organizations opt for a combined approach, integrating security audits and penetration tests into a holistic security assessment.

Advantages

• Streamlines the assessment process by merging policy, procedural, and technical evaluations.

• Offers a complete picture of the organization’s security posture in a single engagement.

• Can be more efficient and cost-effective by addressing both compliance and technical vulnerabilities simultaneously.