In today’s software-driven world, it’s crucial to ensure the security of software during development. Yet many software development life cycle (SDLC) models lack specific emphasis on software security, requiring the addition of secure software development practices or software security frameworks alongside existing SDLC processes to ensure robust security measures.
The National Institute of Standards and Technology (NIST) seeks to address this need with a framework to enhance software supply chain security. NIST’s Secure Software Development Framework (SSDF) outlines a core set of high-level practices you can integrate into any SDLC model.
By following the practices outlined in the SSDF, your organization can:
- reduce vulnerabilities in released software;
- minimize the impact of exploited vulnerabilities; and
- eliminate the root causes of exploits to prevent future recurrences.
Additionally, the SSDF offers guidance to help you manage risks associated with your software supply chain and better align with principles of secure software development.
In this blog post, we explore the SSDF, the details of its four groups of core practices, and the intended outcomes and influence on your existing software development processes.
What is the SSDF?
The SSDF is a guide created by NIST to help organizations develop and maintain secure software systems. NIST describes the SSDF concisely as “a set of fundamental, sound practices for secure software development.”
The SSDF establishes a structured approach to incorporate security measures into existing software development practices, thereby reducing vulnerabilities and improving overall software quality and reliability. NIST based its development of the SSDF on established industry standards and existing secure software development documentation.
The framework aims to enhance software security through the integration of best practices, processes, and activities into an SDLC. It focuses on proactive security measures, addressing vulnerabilities early, and promoting a culture of security with principles such as Shift Left regardless of the SDLC model favored by your organization.
Who should use the SSDF?
The SSDF is designed to benefit two different personas in software development:
- software producers
- software acquirers
Regardless of their size, sector, or level of maturity, the SSDF provides guidance to enhance software security practices and ensure the delivery of reliable and secure software products.
Software producers — such as commercial-off-the-shelf product vendors, government-off-the-shelf software developers, custom software developers, and internal development teams — can leverage the SSDF to establish and strengthen their secure software development practices to help their products meet higher standards of security and resilience.
Additionally, the SSDF remains relevant for software acquirers, encompassing both federal agencies and other organizations. Software acquirers can utilize the SSDF to assess and verify the security posture of the software products they procure. By incorporating the SSDF, they can prioritize acquisition of secure software and make informed decisions to mitigate potential risks associated with software vulnerabilities and supply chain compromises.
Where is the SSDF published?
NIST publishes the framework, and it is freely available on their website within their Computer Science Resource Center (CSRC). NIST is widely recognized as a leading authority in cybersecurity and has a strong reputation for producing authoritative publications, ensuring the legitimacy and reliability of the framework.
How is it maintained?
Executive Order 14028: Improving the Nation’s Cybersecurity called for NIST, among other agencies, to develop initiatives that enhance the security and integrity of software supply chains. With the issuance of Executive Order 14028 in March 2021, NIST's role in maintaining the SSDF, originally released in April 2020, gained added significance.
In February 2022, NIST published its updated (Version 1.1) SSDF to incorporate emerging security practices, evolving threats, and industry advancements, ensuring its relevance in an ever-changing landscape. Changes made in the updated SSDF highlight a greater importance to secure software supply chains, where there’s been an exponential increase in attacks over the past three years alone.
As part of their maintenance process, NIST collaborates with stakeholders, industry experts, and the public to gather feedback and insights. This feedback helps ensure the SSDF remains aligned with the evolving cybersecurity landscape. NIST also conducts periodic reviews, taking into account emerging security practices, evolving threats, and advancements in the software development field.
What are the four groups of core practices put forth in the SSDF?
The SSDF puts forth four groups of core practices to achieve more security and reliability in software. Each group addresses specific aspects of secure software development and software supply chain security. We delve into each of these groups below.
Prepare the Organization
The first group of core practices establishes a runway for successful integration of the SSDF. Prepare the Organization (PO) highlights the significance of preparing both your development team and entire organization for secure software development practices.
This involves a few steps.
- Educate employees about secure coding practices.
- Designate key stakeholders.
- Equip them with the necessary relevant skills.
- Establish robust processes and systems to facilitate secure software development.
By emphasizing shared responsibility, PO ensures the integration of security from the beginning, fostering a culture of secure practices throughout your organization.
Protect the Software
Protect the Software (PS) underscores the need to safeguard software from unauthorized access and malicious actors throughout the development process. It provides guidance on adopting measures such as rigorous access controls, data encryption, strong authentication protocols, as well as archiving and protecting software releases.
PS offers specific tactical guidance to protect the integrity of the software and mitigate potential security risks.
Produce Well-Secured Software
Produce Well-Secured Software (PW) emphasizes the development of software with minimal vulnerabilities. It aligns closely with secure coding standards and provides best practices to prevent, detect, and eliminate security flaws. Adhering to PW involves implementing a security-centric development process, including regular code reviews, comprehensive testing, and continuous monitoring.
By following these practices, security issues can be swiftly identified and resolved, ensuring the production of robust and secure software.
Respond to Vulnerabilities
Respond to Vulnerabilities (RV) focuses on a proactive and structured approach to identify, manage, and remediate vulnerabilities. It incorporates best practices advocated by NIST, such as vulnerability scanning, timely patch management, and responsive incident management.
By promptly addressing vulnerabilities and software risks, your organization can enhance the resilience of your software, reducing the potential for successful cyber attacks.
Why should you leverage the SSDF and better secure your software?
By embracing a culture of security, your organization can effectively integrate new security practices into your existing development workflows.
By adopting the SSDF, your organization can shift toward achievement of these key benefits:
- Proactive security measures: The SSDF encourages organizations to take a proactive approach to security. By integrating security considerations into the SDLC, organizations can identify and address vulnerabilities early on, minimizing the potential for security breaches and mitigating risks.
- Security-first SDLC approach: The SSDF promotes a security-first approach to the SDLC. It emphasizes the importance of incorporating security practices from the initial phases of requirements gathering and design through to coding, testing, deployment, and maintenance. This ensures security remains a priority throughout the entire development process.
- Integration of new security practices: The SSDF helps organizations integrate new and emerging security practices into their existing development workflows. By following the framework's guidance, organizations can stay updated with the latest security practices and adapt their processes to address evolving threats and industry advancements.
In addition to the benefits offered by the SSDF, your organization can also leverage Sonatype's Software Supply Chain Maturity Framework. This framework complements the SSDF by providing guidance on measuring the maturity of your software supply chain. By aligning your software supply chain practices with Sonatype-defined maturity levels, you can further enhance the security and integrity of your software. In our next blog post in this series, we will dig into the connections between the SSDF and Sonatype’s maturity themes and functions.
While implementing the SSDF may initially seem challenging, the framework provides a structured path to develop software that is both functional and secure. By following its principles, organizations can bolster their cybersecurity practices, reduce vulnerabilities, and ultimately build trust in their software products. Embracing the SSDF is a crucial step towards ensuring the security and reliability of your software in today's evolving threat landscape.
