Secure Software Development with the NIST SSDF
With Special Publication 800-218, the US National Institute of Standards and Technology (NIST) has published the Secure Software Development Framework (SSDF). The framework gives organizations a structured approach to improving software security across the entire development lifecycle.
Contents
Structure of the SSDF
The SSDF has three aims:
- reduce the number and severity of vulnerabilities in released software
- reduce the impact of the vulnerabilities that remain
- address security in every phase of the software lifecycle
To achieve these aims, the framework is divided into four practice groups. Each group contains specific practices and related tasks.
Prepare the Organization (PO)
The first group, Prepare the Organization, lays the foundation for secure software development. It covers defining clear security requirements, assigning roles and responsibilities, and implementing supporting tools. Training staff in software security and setting up a secure development environment are also central elements. These measures create the organizational basis on which all further security work builds.
Protect the Software (PS)
The second group, Protect the Software, focuses on protecting the software product itself. This starts with protecting the source code against unauthorized access and tampering. It continues with secure release mechanisms and extends to the secure archiving of software releases. These practices maintain the integrity of the software product throughout development and beyond.
Produce Well-Secured Software (PW)
The third group, Produce Well-Secured Software, builds security directly into the development process. It looks at every aspect of software development from a security point of view:
- threat modeling in the design phase
- continuous code reviews
- thorough security testing
- secure configuration of the software
Documenting security aspects for end users and using automation tools to scale the security practices complete this group.
Respond to Vulnerabilities (RV)
The fourth group, Respond to Vulnerabilities, deals with managing security problems after the software has been released. It covers identifying, assessing, and prioritizing vulnerabilities effectively, and analyzing them thoroughly to prevent similar problems in the future. This proactive approach to fixing vulnerabilities contributes significantly to the continuous improvement of software security.
How the SSDF relates to standards and regulation
A particularly useful feature of the SSDF is that it links to various standards, industry specifications, and regulations. For each practice, the SSDF gives specific references to the relevant documents. Important cross-references include:
- IEC 62443: an internationally recognized series of standards for the security of industrial automation and control systems.
- ISO/IEC 27034: a standard that provides guidance on application security.
- OWASP Application Security Verification Standard (ASVS): a catalog of security requirements and controls that serves as a benchmark for verifying the technical security of applications.
- Executive Order (EO) 14028: a US executive order on improving the nation's cybersecurity.
These links let organizations integrate the SSDF into their existing compliance work. They help ensure that software development not only follows the NIST recommendations but is also consistent with good practice and regulatory requirements.
Introducing the SSDF
The SSDF is deliberately flexible so that it supports different software development methods and environments. Organizations can select and adapt the practices that best fit their specific requirements and risks. Introduce the framework step by step, starting with the most critical practices.
Introducing the SSDF has several benefits:
- better software quality and security
- lower costs, because security problems are found and fixed early
- more trust from customers and partners
- better compliance with regulations and standards
- a more efficient response to security incidents
The introduction also brings challenges:
- a necessary cultural change in the organization
- training and qualifying staff
- integration into existing development processes
- selecting and implementing suitable tools
- continuously improving and adapting the practices
Why the SSDF is worth adopting
The NIST SSDF offers a broad and flexible approach to improving software security. By implementing its practices, organizations can strengthen their software development processes, reduce risks, and deliver more secure products. In a world that is increasingly connected and dependent on software, responsible software development needs frameworks like this one.
