Shift Left Security: Integrating Pentesting Early in Development

TL;DR

In application security,  “shift left” is a guiding principle for how organizations should implement security practices into the development process.  Today’s application security testing tools and technologies are built to facilitate  this security-centric approach, but the term has taken on a new meaning compared to when it first entered the scene years ago. 

Over the past decade, software development has drastically changed with the proliferation of impactful technology, such as APIs and open-source code. However, shift left has remained a North Star for organizations seeking to improve application security. Its meaning has become more nuanced for those attempting to achieve a mature application security framework. 

Read on to learn how penetration testing can be integrated into a shift left security approach, including the benefits, challenges, and best practices for leveraging pentesting early in the software development lifecycle (SDLC).

Integrating Pentesting Early: A Shift Left Approach to Security

Shift left security emphasizes integrating security practices early in the SDLC. Traditionally, security was addressed towards the end of development, but this approach has evolved to emphasize early identification of vulnerabilities. By shifting security left, developers can catch issues before they become costly problems. Proactive security testing plays a crucial role in identifying potential weaknesses in systems or code. Pentesting mimics real-world cyberattacks to uncover vulnerabilities and confirm secure foundations, configurations, or designs, leading to stronger, more resilient software.

What is Shift Left Security?

In short, shift left security is a proactive approach that integrates security measures early in the SDLC, rather than waiting until later stages such as testing or deployment. The term “shift left” comes from the practice of moving security activities to the left side of the SDLC timeline, which traditionally places development and design phases at the start. By identifying and addressing vulnerabilities early—think during planning, design, and coding—organizations can prevent disastrous security issues from emerging later in the process.  

The core principles of shift left security include early threat detection, continuous security testing throughout the SDLC, cross-team collaboration, and the use of automation. Security risks are spotted and mitigated at each phase, ensuring that security is not an afterthought but a foundational aspect of development. Developers, security experts, and other stakeholders collaborate to embed security practices into workflows, while automated tools help detect vulnerabilities more efficiently, enabling smoother integration into continuous delivery pipelines. 

The benefits of shifting security left are significant. It helps reduce the cost of fixing vulnerabilities by addressing them early, avoiding the complex and expensive task of remediating issues after deployment. Early detection minimizes the risk of breaches, ensuring secure software is delivered faster. Additionally, it fosters a security-conscious culture within development teams, ensuring that secure coding practices become ingrained and consistently followed.

The Role of Penetration Testing in Shift Left Security

In the traditional approach, penetration testing occurs after development, often during the final stages or post-deployment, which can delay issue resolution. This reactive approach can’t keep up with the influx of vulnerabilities and exposures. Enter the shift left approach which incorporates penetration testing early in the development process, enabling earlier identification of vulnerabilities—before they can be deeply embedded into the system, reducing risk, and promoting faster and higher quality software delivery.

Key Benefits of Early Penetration Testing

Early penetration testing allows teams to detect and resolve security weaknesses swiftly and effectively. This enables quicker fixes, ensuring the software remains secure throughout its lifecycle, and improves time-to-market by avoiding delays caused by late-stage security discoveries.  

Finding and fixing vulnerabilities early in the development cycle also significantly lowers remediation costs. When issues are discovered later—after deployment or during final stages—the cost of addressing them can be substantially higher due to the complexity of changes required and the potential for widespread impact. Early pentesting prevents any unexpected delays by allowing teams to tackle security issues before they are integrated, leading to more straightforward fixes. 

When security testing is integrated into the development process, developers become more familiar with secure coding practices, while security teams gain a better understanding of the development pipeline. This collaboration ensures that security is prioritized from the start, enhancing communication, knowledge sharing, and the development of more secure applications overall.

Challenges of Integrating Pentesting Early

Balancing speed with thoroughness can be a challenge as developers often prioritize rapid delivery, which can conflict with the in-depth nature of penetration testing. Resource and skill gaps within development or security teams may also hinder effective testing as specialized expertise is required to perform thorough assessments. Keep in mind that automated pentesting tools, while efficient, can generate false positives, requiring manual review and validation, slowing down the process in unforeseen ways. To mitigate these challenges, consider streamlining workflows, upskilling teams, and enhancing validation and prioritization methods to reduce false alarms while maintaining thorough testing.

Best Practices for Shift Left Security with Penetration Testing

To effectively integrate early penetration testing into your strategy, keep in mind the following shift left security practices recommended by The NetSPI Agents.

1. Automating Penetration Testing in CI/CD Pipelines: Automating penetration testing within continuous integration and continuous delivery (CI/CD) pipelines is essential for speed and efficiency. By integrating automated pentesting tools into the pipeline, security assessments can run every time code is updated, providing real-time feedback on vulnerabilities. 
2. Incremental Testing for High-Priority Components: Rather than conducting full-scale penetration tests on all components simultaneously, NetSPI recommends focusing on high-priority or high-risk areas first. Performing incremental testing on critical code sections, such as authentication or sensitive data handling, allows developers to prioritize addressing the most significant vulnerabilities early in the development lifecycle. 
3. Combining Pentesting with SAST/DAST Tools: Combining penetration testing with Static Application Security Testing (SAST) and Dynamic Application Security Testing (DAST) tools provides a comprehensive security strategy. SAST scans the code for vulnerabilities, while DAST tests the running application for security flaws. NetSPI recommends using all three methods together to achieve a more thorough assessment, catching vulnerabilities at different stages. 
4. Using Threat Modeling to Scope Early Tests: Threat modeling helps identify potential attack vectors early, allowing teams to scope penetration tests based on real-world threats. This approach ensures testing is targeted and relevant, reducing wasted effort and ensuring that the most significant risks are addressed proactively and effectively.  

Implementing Shift Left Security in Your Organization

To implement shift left security effectively, start by creating a culture of security awareness across the organization. Encourage all team members to prioritize security from the outset, fostering a mindset that sees security as everyone’s responsibility. Promote collaboration between security, DevOps, and QA teams and integrate security into development, from planning to deployment. This cross-functional teamwork enables faster identification and resolution of vulnerabilities. Invest in training developers on secure coding practices, helping them understand common vulnerabilities and how to mitigate them.

Simplify Proactive Security with NetSPI

It’s time to adopt a proactive, collaborative security approach. NetSPI simplifies the steps toward proactive security by offering a single integrated platform to enable continuous threat expose management. Ready to secure your applications from the start? Contact us to explore tools and strategies for integrating penetration testing into your shift left security framework.