Secure Software Development Lifecycle 101

LEARN on the phases of a software development lifecycle, as well as how to integrate security or take an existing SDLC to the next level: the secure SDLC (software development lifecycle).

The digital transformation that has swept across all industry sectors means that every business is now a software business.

Whether you’re selling software directly to your customers or building it to manage your operations, your organization needs to protect your bottom line by building trust in your software without sacrificing the speed and agility that will keep you competitive in your market. However, many organizations are still lagging behind when it comes to integrating security into their SDLC.

Too many development teams still view security as a bottleneck, an issue that forces them to rework code they thought was done, and prevents them from releasing exciting new features. But insecure software puts your business at increasing risk.

Exciting new features will not protect you or your customers if your product is open to exploitation by hackers.

Your team must embed security by developing secure software processes that enable, rather than inhibit, the delivery of high quality, highly secure products to your market.

Secure your SDLC to secure your business

Ongoing reports of data breaches and supply chain attacks demonstrate that compromised software can have a devastating impact on your business.

When software risk equals business risk, it must be prioritized and managed proactively.

To manage risk and remove friction from your organization’s digital transformation initiatives, your application security programs must “change everywhere.”

This means that security must move from being the last thing development teams tackle to a series of processes and tools that are built into every step of the application development process.

And security programs work best when development teams adopt tools and solutions that integrate seamlessly into development toolchains and workflows.

The SDLC is a well-established framework for organizing application development work from conception to decommissioning.

Over the years, several SDLC patterns have emerged from waterfall and iterative to, more recently, agile, continuous integration and continuous delivery.

Each new model tended to increase the speed and frequency of deployment.

In general, SDLCs include the following phases:

Planning and requirements;

Architecture and design;

Test planning;


Tests and results; and

Release and maintenance.

In early SDLC systems, organizations waited for the testing phase to perform security-related activities.

Worse still, in many cases the insecure code disappeared due to time constraints.

That’s why teams have implemented “left shift” processes to align security activities with development.

As SDLC systems have evolved, this process has extended to the idea of ​​”change everywhere”, which incorporates security concerns into all stages of development.

The later a bug is found in the SDLC, the more expensive it becomes to fix.

When a bug is discovered late in the cycle, developers have to abandon the work they’re doing and go back and review code they may have written weeks ago.

Worse still, when a bug is found in production, the code is pushed back to the start of the SDLC.

At this point, the domino effect can kick in and bug fixing eventually pushes back further code changes.

So not only will the bug cost more to fix as it goes through a second cycle of SDLC, but a different code change could be delayed, which also increases costs.

The best, fastest, and cheapest approach is to embed security testing into every step of the SDLC to help discover and mitigate vulnerabilities early, and embed security as you code.

Security assurance activities include architecture analysis during design, code review during coding and build, and penetration testing before release.

Here are some of the key benefits of a secure SDLC approach:

Your software is more secure;

All stakeholders are aware of security considerations;

You catch design flaws early, before they’re coded;

You reduce your costs, thanks to the early detection and resolution of defects; and

You reduce the overall intrinsic business risks for your organization.

How does a secure SDLC work?

Generally speaking, a secure SDLC involves integrating security testing and other activities into an existing development process.

Examples include writing security requirements alongside functional requirements and performing an architecture risk analysis during the SDLC design phase.

There are many secure SDLC models in use, but one of the best known is the Microsoft Security Development Lifecycle, which outlines 12 practices organizations can adopt to increase the security of their software.

There is also the National Institutes of Standards and Technology’s Secure Software Development Framework, which focuses on security-related processes that organizations can incorporate into their existing SDLC.

How to start?

If you’re a developer or tester, here are some things you can do to move to a secure SDLC and improve your organization’s security:

Educate yourself and your colleagues on secure coding best practices and available security frameworks;

Perform a risk analysis of the architecture at the start;

Consider security when planning and creating test cases; and

Use code analysis tools for static analysis, dynamic analysis, and interactive application security testing.

How do you progress beyond the basics?

Beyond these fundamentals, management must develop a strategic approach for a more significant impact.

If you’re a decision maker interested in implementing a complete secure SDLC from scratch, here’s how to get started.

Perform a gap analysis to determine what activities and policies exist in your organization and how effective they are.

Create a software security program or software security initiative (SSI) by setting realistic and achievable goals with defined indicators of success. Formalize the processes for security activities within your ISS.

Invest in safe coding training for developers and the right tools. Use outside help if needed.

And after?

Does your organization already follow a secure SDLC? If so, congratulations. But there is always room for improvement.

You can benchmark your security program against the programs of other organizations.

Building Security In Maturity Model (BSIMM) can help you do that.

Over the past decade, BSIMM has tracked the security activities performed by more than 100 organizations.

Since every organization and every SDLC is different, BSIMM doesn’t tell you exactly what you need to do, but its observation model shows you what others are doing in your own industry – what works and what doesn’t. .


Comments are closed.