Security Audit or Penetration Testing: Which Do You Need?

Is the acquired information system secure enough to be facing the Internet? What is the security level of the system? Different terms are often used for evaluating the security of technical systems, even though the need might be the same: one person wants a security audit, another wants penetration testing, and a third seeks a security review. In this article, we aim to clarify the meanings and differences between security audits and penetration testing.

What is a Security Audit? 

A security audit involves reporting on the implementation of security requirements. Typically, an audit is needed to report the fulfillment of third-party requirements in an information system. Such requirements may include laws or regulations concerning personal or health data. GDPR is the obvious case in point, but also NIS2 and Cyber Resilience Act have their say about conducting security tests periodically, as are standards such as ISO27001 or PCI DSS. Application security can be evaluated based on standards such as OWASP ASVS. 

The purpose of a security audit is to report whether the inspected system complies with the requirements. If deficiencies are found, they are corrected. From the report's perspective, the result is binary: either the requirements are met or they are not. A security audit answers the question of how well security requirements are met. 

What is Penetration Testing? 

Penetration testing involves reporting on security vulnerabilities, deficiencies, and the risks they pose. The target of penetration testing can be an internet-connected application, system, device, or their combination. 

The goal of the testing is to find security vulnerabilities that can be exploited to penetrate, for example, the internal network and servers of the target organization. As the name suggests, the testing aims to bypass protections layer by layer until access to sensitive or otherwise exploitable information is achieved. 

Penetration testing: 

• Reveals the security weaknesses of the system as a whole at the system, network, and application levels.
• Reports the type of risk the deficiencies cause: does it endanger sensitive information in the system, or do the deficiencies allow the system to be used as a foothold for deeper intrusion into the organization’s network?
• Can also answer the question: what is the easiest route for an attacker to enter the organization?

How Does Security Auditing Differ from Penetration Testing? 

Penetration testing differs from auditing in that the system’s security requirements do not guide the process. The approach is exploratory, adaptive, and above all, creative, not based on predefined checklists or requirements. It also considers the business context, as otherwise the risks associated with each finding are solely analysed in the technical domain.  

A security audit may include a vulnerability scan, but the vulnerabilities are not usually actively exploited. In penetration testing, vulnerability scanning is just one step: identified vulnerabilities are actively exploited to find new security gaps. Active exploitation helps eliminate "false positive" findings reported by scanners and assess the true risk level of vulnerabilities. 

Auditing often involves interviews and reviewing available documents. Penetration testing is based on the attacker’s perspective and is a technical assessment of security. 

Security Auditing vs. Penetration Testing: Benefits

Benefits of Security Auditing:

• Comprehensive understanding of security

• Identification of risks and weaknesses

• Assurance of compliance with requirements 

Benefits of Penetration Testing:

• Practical testing of system and application security from a malicious attacker’s perspective

• In-depth understanding of weaknesses and areas for improvement

• Enables the implementation and prioritization of corrective measures

• Testing on an annual basis or flexible schedule whenever updates are made to applications, networks, or systems

• Helps organizations demonstrate compliance by showing that the security of target systems has been tested against cyber threats 

How to Choose the Right Approach?

The choice depends on your organization’s needs and resources. If you want to ensure compliance, an audit might be a good option. 

Penetration testing is a better choice when you need a realistic view of the security level of your systems and applications. Pentesting is especially appropriate if there are no external or other requirements for conducting an audit. 

For business-critical, frequently updated, or publicly accessible web applications, a continuous security assurance model (PTaaS) is particularly suitable.

Are You Managing Cyber Risks or Compliance?

Security audits and penetration testing are not mutually exclusive. It could be that security requirements only apply to the application and not its runtime environment. In this case, the application can be audited and compliance reported accordingly. Penetration testing, on the other hand, reveals the security status of the application's runtime environment.

Summary

• Security audits and penetration tests are methods for evaluating the technical security of a system. They differ, even though both terms may be used to describe security evaluation.

• Security audits report on compliance with requirements. Penetration testing reports on the risk posed by security deficiencies and provides recommendations for risk management actions. 

• Security should be tested even when there are no specific requirements.

Whether your organization chooses testing or auditing, the most important thing is to invest in the assessment and improvement of the security of digital services. 

Could we assist in your security evaluation? Contact us!