# SSDF: Secure Software Development Framework
The Secure Software Development Framework (SSDF) is NIST Special Publication 800-218, published in February 2022 as the federal government's standardized approach to integrating security practices throughout the software development lifecycle. SSDF emerged from Executive Order 14028 on Improving the Nation's Cybersecurity, which mandated that software vendors selling to the federal government demonstrate secure development practices.
SSDF represents a fundamental shift from treating security as a post-development activity to embedding it as a core engineering discipline. The framework recognizes that software vulnerabilities introduced during development are exponentially more expensive to fix in production than during design and coding phases. SSDF provides a common vocabulary and set of practices that organizations can use to demonstrate secure development capabilities to government customers, but its value extends far beyond compliance requirements.
The framework consists of four practice groups spanning the entire development lifecycle: Prepare the Organization (PO), Protect the Software (PS), Produce Well-Secured Software (PW), and Respond to Vulnerabilities (RV). Each practice group contains specific practices, and each practice includes implementation examples that organizations can adapt to their development processes and toolchains.
SSDF differs from previous secure development guidance by focusing on outcomes rather than prescriptive tools or processes. It acknowledges that organizations using waterfall, agile, or DevOps methodologies can all achieve secure software outcomes through different implementation approaches. This flexibility has made SSDF practical for adoption across diverse software development environments, from traditional enterprise IT to cloud-native startups.
SSDF organizes secure development into four interconnected practice groups that create a comprehensive security posture throughout the software lifecycle.
Prepare the Organization (PO) establishes the foundational elements that enable secure development. PO.1 requires organizations to define security requirements for software development, including security and privacy requirements that software must meet. This goes beyond generic security policies to include specific requirements like input validation standards, encryption requirements, and authentication mechanisms. PO.2 focuses on implementing secure development processes and procedures, including secure coding standards, code review processes, and security testing procedures. PO.3 addresses secure environments for software development, requiring organizations to separate and protect development, testing, and production environments. PO.4 mandates establishing secure configurations for development tools and environments. PO.5 requires organizations to identify and confirm the security of third-party software components before incorporating them into applications.
Protect the Software (PS) focuses on protecting software code, components, and development artifacts from unauthorized access and tampering. PS.1 requires protecting code integrity through version control systems, access controls, and change management processes. Organizations must implement controls that prevent unauthorized modification of source code and maintain audit trails of all changes. PS.2 addresses protecting software from unauthorized access by implementing appropriate access controls for code repositories, development environments, and software distribution mechanisms. PS.3 focuses on archive and version control, requiring organizations to maintain integrity of software components and their provenance throughout the development process.
Produce Well-Secured Software (PW) encompasses the technical practices that result in secure software. PW.1 requires design review processes that identify security and privacy issues early in development. This includes threat modeling, security architecture review, and design pattern analysis. PW.2 mandates code review processes that identify security vulnerabilities, including both manual code review and automated static analysis. PW.3 requires organizations to verify third-party software components meet security requirements before integration. PW.4 focuses on security testing throughout development, including dynamic application security testing (DAST), interactive application security testing (IAST), and penetration testing. PW.5 addresses configuration and vulnerability management for software components. PW.6 requires organizations to review and address discovered security vulnerabilities and verify remediation effectiveness. PW.7 mandates that organizations review software for vulnerabilities prior to release. PW.8 requires organizations to maintain detailed records of security-relevant software information. PW.9 focuses on ensuring software integrity and authenticity through code signing, software bills of materials (SBOMs), and provenance documentation.
Respond to Vulnerabilities (RV) establishes processes for identifying, analyzing, and remediating vulnerabilities throughout the software lifecycle. RV.1 requires organizations to identify and confirm vulnerabilities in their software through vulnerability disclosure processes, security research, and ongoing monitoring. RV.2 focuses on assessing, prioritizing, and remediating vulnerabilities based on risk to users and systems. RV.3 requires organizations to analyze vulnerabilities to identify root causes and prevent similar issues. This includes reviewing development processes, tools, and training to address systemic security issues.
Implementation of SSDF practices scales with organizational maturity and development processes. A startup developing a single web application might implement PW.2 (code review) through peer review processes and automated tools integrated into their continuous integration pipeline. An enterprise software vendor might implement the same practice through formal code review boards, multiple automated analysis tools, and security champion programs across development teams.
The framework's strength lies in its recognition that different organizations will implement the same security outcomes through different means. SSDF provides the "what" of secure development while allowing organizations flexibility in "how" they achieve those outcomes within their existing development methodologies and toolchains.
SSDF addresses the fundamental economics of software security. Fixing a security vulnerability in production costs 30 to 100 times more than addressing the same issue during design or development. Organizations that implement SSDF practices reduce vulnerability remediation costs while improving software quality and customer confidence.
The compliance impact extends beyond federal contracts. Major corporations are increasingly requiring SSDF compliance from software vendors as part of vendor risk management programs. Financial services companies, healthcare organizations, and critical infrastructure operators are incorporating SSDF requirements into vendor assessments and software procurement processes. Organizations that proactively adopt SSDF practices position themselves competitively for both government and commercial opportunities.
The framework addresses a critical gap in how organizations approach software security. Traditional approaches treat security as a post-development activity, leading to expensive vulnerability remediation cycles and customer trust issues when security flaws are discovered in production. SSDF shifts security left in the development process, making security a shared responsibility between development and security teams rather than a security team afterthought.
Cyber insurance providers are beginning to recognize SSDF implementation as a risk reduction factor. Organizations with documented secure development practices may qualify for lower premiums or better coverage terms. As software supply chain attacks increase in frequency and impact, insurance providers view secure development practices as essential risk controls.
Common misconceptions about SSDF include viewing it as a waterfall-only framework or assuming it requires specific tools or technologies. SSDF is methodology-agnostic and tool-agnostic. Agile teams can implement SSDF practices through sprint security requirements, automated testing in continuous integration pipelines, and iterative threat modeling. DevOps teams can embed SSDF practices in infrastructure as code, automated security testing, and continuous monitoring.
Another misconception is that SSDF compliance is binary. SSDF implementation is progressive. Organizations typically begin with practices that align with existing processes and gradually expand implementation across all practice groups. The framework explicitly supports phased implementation based on organizational priorities and risk assessments.
CDA approaches SSDF through the Risk Governance and Assurance (RGA) domain using the Perpetual Compliance Assurance (PCA) methodology. While most organizations treat SSDF as a project with a defined end state, CDA recognizes that secure software development is an ongoing capability that requires continuous attention and improvement.
The conventional approach to SSDF implementation follows a familiar pattern: gap assessment, remediation planning, implementation, and validation. Organizations check the compliance box and move on to other priorities. Six months later, development teams have reverted to previous practices, security tools are generating unreviewed alerts, and the organization's secure development posture has degraded significantly.
CDA's PCA methodology treats SSDF compliance as a state that organizations must actively maintain. This means implementing monitoring and measurement systems that continuously validate SSDF practice implementation. For example, rather than implementing code review processes and assuming they will continue operating effectively, PCA establishes metrics that track code review completion rates, security issue identification rates, and remediation timeframes. When these metrics indicate process degradation, corrective actions are triggered automatically.
The RGA domain owns SSDF implementation because secure software development is fundamentally a risk management activity. Development teams make dozens of risk decisions daily: whether to use a third-party library, how to implement authentication, whether to prioritize security testing or feature delivery. SSDF provides the governance structure and assurance processes that ensure these decisions align with organizational risk tolerance.
CDA differs from conventional SSDF approaches in three key areas. First, we integrate SSDF practices with business processes rather than treating them as compliance overhead. Security requirements become engineering requirements. Code review becomes part of quality assurance. Vulnerability management becomes part of product maintenance. Second, we implement continuous monitoring of SSDF practice effectiveness rather than periodic assessments. Third, we treat SSDF as a capability development program rather than a compliance project, focusing on building organizational competencies that improve over time rather than achieving point-in-time compliance.
This approach recognizes that software development is a creative process performed by humans who work most effectively when security practices enhance rather than impede their productivity. Sustainable SSDF implementation requires practices that integrate naturally with how development teams actually work, not how compliance frameworks assume they should work.
• SSDF is mandatory for software vendors selling to the federal government and increasingly required by commercial customers as part of vendor risk management programs.
• The framework focuses on four practice groups spanning the entire development lifecycle: Prepare the Organization, Protect the Software, Produce Well-Secured Software, and Respond to Vulnerabilities.
• SSDF implementation is methodology-agnostic and tool-agnostic, allowing organizations to achieve secure development outcomes through practices that align with their existing development processes.
• Sustainable SSDF implementation requires treating secure development as an ongoing capability rather than a point-in-time compliance project, with continuous monitoring and improvement of security practices.
• Organizations that implement SSDF practices reduce vulnerability remediation costs, improve software quality, and position themselves competitively for government and commercial opportunities requiring demonstrated secure development capabilities.
• Perpetual Compliance Assurance (PCA): Compliance Is a State • Software Bill of Materials (SBOM) Management • DevSecOps Implementation Framework • Third-Party Risk Management for Software Components • Vulnerability Management Program Development
• NIST Special Publication 800-218, "Secure Software Development Framework (SSDF) Version 1.1: Recommendations for Mitigating the Risk of Software Vulnerabilities," National Institute of Standards and Technology, April 2022.
• Executive Order 14028, "Improving the Nation's Cybersecurity," The White House, May 12, 2021.
• "The Economic Impacts of Inadequate Infrastructure for Software Testing," National Institute of Standards and Technology, Planning Report 02-3, May 2002.
• NIST Special Publication 800-161 Rev. 1, "Cybersecurity Supply Chain Risk Management Practices for Systems and Organizations," National Institute of Standards and Technology, May 2022.
• "Software Supply Chain Security Guidance," Cybersecurity and Infrastructure Security Agency, September 2022.