Security in software development and DevSecOps

Informatec Digital » Resources » Security in software development and DevSecOps

Software security is no longer an optional extra added at the end of a project, but a key component from the very first application sketch. In a world where code is deployed multiple times a day and where cyberattacks are increasingly sophisticated, continuing to rely on last-minute manual reviews is a recipe for disaster.

Integrating security throughout the entire development lifecycle (from initial concept to production maintenance) is the foundation of approaches like DevSecOps, developer-centric security, and secure SDLC models from frameworks such as OWASP SAMM or the NIST SSDF. The goal is simple to state but complex to achieve: to create secure software by design without hindering business agility and preventing security from becoming a bottleneck.

What is security in software development and why does it matter?

When we talk about software development security, we're referring to all the practices, tools, and processes applied to ensure an application withstands attacks, preserves data integrity, and maintains service availability throughout its lifecycle. It's not just about "putting in a firewall" or using encryption, but about designing and programming the software in a way that makes security vulnerabilities less likely.

Malware attacks and software vulnerabilities can compromise authentication, authorization, integrity, and confidentiality. If these threats are addressed during the design phase, many can be mitigated before they become a problem in production, preventing emergency patches and data breaches.

The central idea is that every piece of software should undergo security testing before reaching the user, and that these tests shouldn't be an isolated "filter," but rather a routine part of every version. This results in more resilient software that doesn't need to accumulate layer upon layer of additional security as vulnerabilities are discovered.

The ultimate goal is to achieve secure-by-design applications , with controls built into their architecture, frequent automated testing, and a culture where developers, security, and operations all work together. This requires a conscious effort from the entire technical team, not just a small group of cybersecurity specialists.

DevSecOps and developer-centric security

The term DevSecOps emerged to address a very specific problem: traditional models, in which the security team only joined at the end of the development cycle, no longer fit with frequent releases, agile methodologies, and CI/CD pipelines. Previously, updating an application once or twice a year allowed for a thorough review; now, with continuous deployments, that approach has become an unacceptable obstacle.

DevSecOps promotes the seamless integration of security into Agile and DevOps , so that application and infrastructure security is addressed from the outset and continuously. The idea is to detect and fix vulnerabilities as soon as they appear, when they are still inexpensive to remediate, rather than discovering them shortly before deployment.

Furthermore, DevSecOps promotes security as a shared responsibility : development, operations, and security collaborate closely, rather than working in silos that only communicate at the end. The motto of this approach is often summarized as "software, safer, sooner": delivering faster and more secure software by automating controls and reducing friction in the development lifecycle.

A key pillar of this philosophy is developer-centric security . Instead of the security team acting as a "police force" at the end of the process, security tools are brought closer to the developers' own work environment, for example, by integrating scanners into the IDE or version control system. This way, some of the analysis, testing, and patching is done directly from the developer's keyboard.

This approach of "bringing security closer to the code" allows vulnerabilities to be discovered and fixed almost as soon as they are written, without waiting for periodic audits or large-scale penetration testing. As a result, development teams stop seeing security as a nuisance that slows down their work and instead embrace it as a core quality criterion.

Security is built into every stage of the SDLC.

For security to be truly effective, it must be integrated into all phases of the development lifecycle (SDLC), not treated as a final "quality check." Treating security only as a concern at project closure creates a bottleneck for the security team, especially since they can't possibly be experts in all the technologies and cloud environments used today.

The modern approach proposes security that is “woven” throughout the entire SDLC: from defining requirements, through planning and design, to implementation, testing, deployment, and maintenance. The entire organization internalizes that security is an essential part of product success , not a separate concern that can be postponed.

Previously, security reviews were primarily manual testing and isolated tools for each application or service, combining spot scanners with penetration testing. Today, tools are designed with integration and automation in mind: they connect to CI/CD pipelines, incident tracking systems, and code repositories, enabling a much smoother workflow.

Vulnerability scanners are integrated into the continuous integration process, so every code change is automatically analyzed before moving to the next stage. At the same time, findings are logged as regular tasks, visible to the entire team, making it easier to prioritize, track, and measure resolution times.

All of this means that security is no longer an afterthought but becomes a structural component of the SDLC . Instead of simply “passing a security check” right before deployment, the organization assumes that every commit, every merge, and every delivery is part of a continuous chain of security checks.

Common software security practices

Within this way of working, there are a number of software security initiatives that many organizations already implement or are beginning to adopt. It's not an exhaustive list, but it helps to understand what kinds of activities we should integrate into the SDLC to strengthen security.

A key first step is static code analysis (SAST). This involves analyzing the source code (including infrastructure as code) to detect unsafe programming patterns or known vulnerabilities. It's typically an automated process that can be run on every commit or push, providing developers with near real-time feedback.

On the other hand, dynamic security analysis (DAST and similar approaches) evaluates the entire application and its underlying infrastructure while it is running. This includes, for example, port scans, cross-site scripting tests, container configuration reviews, and analysis of internet-facing services to identify vulnerabilities that are only visible when the system is operational.

Alongside automated tools, manual code reviews remain essential. While many functions are already reviewed for logical bugs, incorporating a security perspective into these code reviews allows for the detection of less obvious vulnerabilities that a scanner might miss. However, this does require the team to have some training in attack patterns and best practices.

Penetration testing goes a step further: experts are hired to act as attackers and attempt to compromise the infrastructure or applications. They can use anything from automated analysis to real exploits, and the result is usually a report detailing vulnerabilities that standard tests missed, with specific recommendations for mitigating them.

A related but different approach is Bug Bounty programs . This model invites researchers and advanced users to report vulnerabilities in exchange for a financial reward or recognition. It's an effective way to channel third-party findings and turn potential attackers into collaborators.

Finally, we must not forget security training for technical staff . The threat landscape changes rapidly: what made sense ten years ago may be bad practice today. Keeping developers up-to-date on the OWASP Top 10, emerging attacks, and secure design patterns greatly reduces the risk of human error, which remains the cause of a significant portion of security breaches.

The Secure Software Development Life Cycle (Secure SDLC)

Integrating security into the SDLC isn't about adding an "extra phase" at the end, but rather about weaving practices and controls into the existing stages. This creates a sustainable process that delivers real value without disrupting the team's dynamics. A secure SDLC typically includes the following phases:

The requirements stage clearly defines the problem to be solved and the level of security needed. This is the time to transform incidents, requests for new features, and known vulnerabilities into concrete projects, assessing their impact on overall risk. Involving the security team at this stage helps prioritize effectively and understand the implications of each change.

Next comes the planning phase , where decisions are made about what will be built and how it will be approached. It is important that security also participates in this phase, validating that the planned solution does not introduce new attack vectors and that business objectives are aligned with data protection, regulatory compliance, and resilience requirements.

The solution design phase focuses on the architecture: which systems interact, what services are created, how they relate, and what data flows are established. Diagrams should be reviewed with the security team to identify potential vulnerabilities in trust boundaries, entry points, authentication mechanisms, encryption, and so on. Fluid communication in these early stages prevents the discovery of serious problems once everything is already programmed.

Next comes implementation , the moment to translate the design into code. This is where practices such as static analysis at each commit, integrating security rules into the CI pipeline, and conducting code reviews with a focus on security become crucial. The sooner a flaw is detected in the code, the lower the cost of fixing it.

Once the code is ready, it moves to the testing and implementation phase . In addition to functional tests, it's advisable to include more comprehensive security analyses here: DAST scans, manual security testing of critical functionalities, and, when resources allow, penetration testing focused on major changes. The findings at this stage should be used to adjust automated tools to prevent regressions.

After deployment, preventative maintenance begins . Even if the software is released to production "without known vulnerabilities," the environment and threats change: new CVEs appear, dependency flaws are discovered, legal requirements are modified, and so on. The maintenance phase includes monitoring for new vulnerabilities, updating components, reviewing security logs, and responding to incidents.

The entire process is circular: each new bug, improvement, or vulnerability discovered feeds back into the requirements phase . A secure SDLC is therefore a cycle of continuous improvement, not a linear path. This mindset helps teams refine their controls and tools with each iteration, instead of thinking that "everything is done" after a deployment.

Reference frameworks: OWASP SAMM and NIST SSDF

For organizations that want to go a step further, it is very useful to rely on established maturity models and secure development frameworks . Two of the most relevant are the OWASP SAMM model and the NIST SSDF framework, which offer practical guidance for integrating security into development processes.

The OWASP Software Assurance Maturity Model (SAMM) is the evolution of OWASP's former CLASP. It proposes a set of security practices organized by domains (such as governance, building, verification, and deployment), with different maturity levels. The idea is that each organization adapts these practices to its own risk profile, rather than trying to apply a rigid list of controls.

The NIST Secure Software Development Framework (SSDF) outlines fundamental secure development practices based on recommendations from multiple expert organizations. It divides the secure SDLC into four main sections: preparing the organization, securing the software, producing secure software, and responding to vulnerabilities. Each section includes specific activities that can be implemented gradually.

“Preparing the organization” means getting people, processes, and technologies ready so that secure development is a cross-cutting practice, both at the corporate level and within each team. “Protecting the software” encompasses measures to prevent unauthorized manipulation of code, build artifacts, and the supply chain.

The "producing secure software" block focuses on minimizing vulnerabilities in each version , integrating static analysis, dependency review, container scanning, and similar controls into daily operations. Finally, "responding to vulnerabilities" refers to identifying overlooked flaws, correcting them quickly, and adjusting the process to prevent their recurrence.

Training, Threat Modelling and safety culture

For all of this to work, simply installing tools isn't enough; it requires building a shared security culture within the team. This means developers must understand that protecting applications is part of their job and that security teams must be integrated into daily operations, not just when an incident occurs.

Specific training is a good starting point. Empowering developers to identify vulnerabilities and write more secure code drastically reduces the occurrence of basic errors. Resources like the OWASP Top 10 help identify the most common weaknesses in web applications and understand how attackers think.

Another high-impact practice is Threat Modelling . This involves analyzing an application (or a new feature) from the attacker's perspective: what assets need protection, what inputs exist, what data flows are critical, and what vulnerabilities could be exploited. Based on this analysis, mitigations are designed and incorporated into the technical design itself.

If performed during the design phase, threat modeling influences the architecture from the outset , preventing insecure solutions that would later require rewriting. Data flow diagrams and known attack patterns are typically used to structure the analysis, involving both development and security teams.

In parallel, it's important to encourage development teams to learn to think like an attacker . This doesn't mean everyone needs to be an expert penetration tester, but rather that they understand how small vulnerabilities combine to create a larger attack, how credentials are stolen, or how weak cloud configurations are exploited.

Limitations of traditional penetration testing

Traditional penetration testing remains a valuable tool, but it has limitations when applied in environments with continuous deployments. By definition, a pentest provides a snapshot of security at a specific point in time: it assesses the state of the application and infrastructure as they are on that day.

As soon as the team deploys new versions or changes configurations, some of the findings may become outdated . If releases are frequent, maintaining full penetration tests after each change becomes impractical in terms of time and cost.

Furthermore, when a penetration test is performed at very advanced stages of the development lifecycle, the vulnerabilities discovered are often costly to fix , frequently requiring complex security updates . Sometimes this involves modifying key components or rewriting entire parts of the application, with the resulting impact on planning, budget, and team morale.

And in organizations with many services and applications, it's difficult to scale manual penetration testing across the entire catalog. There's a tendency to prioritize only the most critical systems, leaving gaps in other areas that can also be exploited by attackers.

Continuous safety testing of CI/CD pipelines

To adapt to this pace of change, models such as continuous security testing in the CI/CD pipeline are emerging, combining 24/7 automated scans with targeted, one-off manual tests. The idea is to move from ad hoc audits to a constant flow of vulnerability detection and remediation.

This approach blends automated scanners that check applications, web assets, APIs, and exposed surfaces with the intervention of penetration testing experts who investigate the most complex findings and look for logical vulnerabilities that the tools cannot detect on their own.

The major advantage is that teams receive fast and detailed information about security issues, even when the CI/CD pipeline is very fast. This reduces the window of exposure because vulnerabilities are identified and fixed before the affected code reaches (or remains in) production for an extended period.

Another benefit is that continuous testing facilitates the link between vulnerability management and application security . Frequent reports, with clear lists of vulnerabilities and their evolution over time, help in making risk decisions, prioritizing fixes, and justifying investments in security improvements.

Some services even offer free retesting after applying fixes, allowing you to verify that the solutions actually work and that no regressions have been introduced. This all fits perfectly with the continuous improvement ethos of DevSecOps.

Typical DevSecOps components and tools

In practice, a DevSecOps environment relies on several key technological components . Continuous integration (CI) unifies the work of all developers and automatically runs unit, integration, and security tests every time new code is integrated.

Continuous delivery (CD) ensures that software is always ready for deployment by sequentially verifying and approving software (including security checks) at each stage. Only versions that pass all defined controls are promoted to higher-level environments.

Security automation is achieved through SAST and DAST tools, dependency scanners, infrastructure-as-code analysis, and container reviews. These tools are integrated into the CI/CD pipeline, in systems like Jenkins, GitLab CI, or similar, so they run without manual intervention.

Vulnerability management solutions are also commonly used to centralize findings, prioritize risks, and track their resolution. Alongside these, secrets management tools (such as Vault) prevent credentials and keys from being exposed in code or deployment configurations.

Finally, continuous monitoring and auditing rely on observability and SIEM platforms (such as ELK or Splunk) that collect logs, detect anomalous behavior, and facilitate compliance audits. This layer completes the loop, enabling the detection of production incidents and timely response.

Applying DevSecOps to mobile app development

When we talk about mobile applications , the DevSecOps approach must be adapted to their specific characteristics. The planning and design phase must consider specific risks: device permission management, secure credential storage, communication encryption, and compliance with regulations such as GDPR.

During development, SAST scanners adapted to languages ​​like Kotlin, Swift, and Java are used, and external dependencies and SDKs are carefully reviewed. Many vulnerabilities in mobile apps arise precisely from poorly maintained third-party libraries or those with excessive permissions.

In the testing phase, DAST scans are combined with mobile-specific tests : man-in-the-middle (MITM) attack simulation, binary integrity verification, local storage analysis, and backend API interaction review. This helps identify flaws in both the app and the services it consumes.

Integration into the CI/CD pipeline means that every commit undergoes automated security checks , ensuring that no version with serious flaws reaches app stores. Furthermore, a post-deployment monitoring system is configured to detect unusual behavior, error spikes, or patterns that might indicate an attack.

Finally, a clear incident response process is defined to enable the rapid release of urgent patches if a critical vulnerability is discovered in production. The ability to react and update the application quickly is key to maintaining user trust.

Taken together, all these practices, frameworks, and tools allow security to cease being an obstacle and become an ally of agile development. By involving developers from the outset, automating testing with each change, and leveraging standards such as OWASP SAMM or NIST SSDF, organizations can create more robust software, reduce the cost of bug fixes, and be much better prepared for a constantly evolving threat landscape.