OSS Security: A Complete Guide to Open Source Software Risk

May 10, 2024
By Aaron Linskens

Open source software (OSS) security starts with understanding the risks introduced by the open source components that power modern software.

Open source software has become the foundation of modern application development. Most organizations no longer build applications from scratch. Instead, they assemble software from thousands of open source and third-party components.

That shift has fundamentally changed how organizations manage software risk. When developers adopt an open source component, they are not simply consuming code. They are inheriting the security practices, maintenance decisions, dependency relationships, and long-term viability of the project behind it.

As a result, evaluating OSS security has become a critical part of managing software supply chain integrity. Organizations must examine the component’s immediate functionalities, the health of the software project, its vulnerability history, the activity from the contributor community, and the responsiveness of its maintainers.

A comprehensive OSS security evaluation entails:

• Scrutinizing the development methodology;
• Gauging the project community’s activity;
• Analyzing the codebase’s security, particularly in terms of open source vulnerabilities;
• Assessing the open source project maintainer’s level of involvement and responsiveness to security issues serves as an important element for review.

This guide explores how to evaluate OSS security, identify common open source risks, strengthen software supply chain security, and use practices such as software composition analysis (SCA), software bills of materials (SBOMs), dependency management, and open source governance to reduce risk throughout the software development lifecycle.

What is OSS Security and Why Does It Matter?

OSS security is the practice of ensuring the safe usage of software components that are developed and distributed as open source.

Evaluation of OSS security encompasses various factors, many of which will be unique to different organizations. Notably, these factors pertain to the software’s design, code quality, and level of support from the OSS community.

When you leverage OSS, you trust the developers of that specific software project and their presumable commitment to ensuring its security. However, this trust remains incomplete until you assess the software yourself and measure its security against a defined set of standards. Your assessment of OSS security is necessary. It’s an assurance of the software’s security posture in the larger context of your software development life cycle (SDLC).

OSS security and software supply chain security are inseparable. One can’t exist without the other because the security of the software supply chain often depends on the security of the OSS components entering development environments, CI/CD pipelines, and production systems.

Common OSS Security Risks and Open Source Vulnerabilities

While OSS presents numerous advantages due to its open and adaptable nature, it also contains security complexities that require specific attention, especially in the context of software supply chains.

Consider the following OSS security risks:

• Challenges stemming from a project’s open nature: The free accessibility of the source code allows for collaborative improvements in which maintainers and contributors find and fix bugs. However, this openness also means threat actors can readily analyze the code to find and exploit open source vulnerabilities.
• Lack of comprehensive testing: Open source projects typically lack centralized quality control, resulting in no guarantee that the code has been rigorously tested for security flaws. An absence of efficient testing procedures can lead to latent bugs or open source vulnerabilities slipping through the cracks.
• Limited vendor accountability: Unlike commercial software vendors, who often provide dedicated support, open source projects tend to lack the structure or resources required to take accountability for security issues. A decentralized structure, or a reduced resource, could lead to delays in addressing open source vulnerabilities, potentially exposing users of that OSS to related risks.
• Transitive dependency risk: Many open source components rely on additional software dependencies that developers may not directly select or review. These transitive dependencies can introduce open source vulnerabilities, licensing concerns, or maintenance risks that remain hidden without visibility into the full dependency tree.
• Software supply chain attacks: Threat actors increasingly target software supply chains by compromising open source packages, maintainer accounts, or distribution mechanisms. Attacks such as dependency confusion, typosquatting, and malicious package injection can introduce risk even when organizations believe they are consuming trusted software.

While OSS’s collaborative spirit can facilitate bug identification and remediation, it can also expose the code to exploitation by threat actors. By prioritizing OSS security in your SDLC, you can harness open source's advantages while proactively addressing its associated risks.

How to Conduct an Open Source Risk Assessment

To fortify OSS security in your SDLC, take a proactive approach. As you explore strategies to elevate your OSS security, several critical aspects come into play.

Below, we delve into strategic measures that can substantially enhance your OSS security posture:

1. Review code quality: Before utilizing an open source codebase, it's crucial to check the quality of the code. This is pivotal because code quality directly influences security. Inadequate code quality increases susceptibility to security vulnerabilities.
2. Evaluate open source licensing: Thoroughly assess the software’s licensing terms. Confirm whether or not the license permits redistribution or modification and if there are any special conditions. Also, consider the potential ramifications of the license in your specific use case, particularly in a case such as GPL which might introduce risks for closed-source products as opposed to licenses such as BSD or MIT.
3. Gauge community involvement: Ensure a community actively maintains the software project. Continued involvement from its original maintainers can be a good sign as well, but note that they could also have passed the reins to new champions to improve upon or carry on the success of the project. A balanced combination of community contributions and oversight can enhance the software's stability and security over the long term.
4. Check code maintenance: To gauge the software’s health and security status, pay attention to both code maintenance practices and repository updates. Ensure maintainers or the community promptly address bug reports and security vulnerabilities. Assess the frequency of repository updates, as regular updates often indicate a well-maintained project, while prolonged inactivity might suggest potential risks. Also, check the version of the open source project you’re considering. Generally, the earliest versions tend to exhibit more security issues due to a gradual identification of vulnerabilities over time.
5. Make security assessments: When evaluating software security, consider two risk factors: vulnerabilities, which are often unintentional weaknesses, and malicious contributions, which are deliberate insider threats to software. Gather insights from news, blogs, and developers to gain a comprehensive understanding of potential vulnerabilities or past instances of harm associated with the software. This approach ensures a thorough assessment of OSS security challenges and risks.
6. Check for SBOM availability: Determine whether the project publishes a software bill of materials (SBOM). Projects that provide an SBOM offer greater transparency into component composition, dependency relationships, and software supply chain exposure.

By using these strategies to evaluate OSS, you give your organization the best chance to remain empowered against the evolving landscape of threats and challenges. However, evaluating an open source project is only the beginning.

Many organizations treat OSS security as a project selection exercise, but open source risk is not static. New vulnerabilities are disclosed, maintainers change, dependencies evolve, and threat actors continually develop new ways to target software supply chains. Effective OSS security requires continuous monitoring throughout the software development life cycle.

Using Software Composition Analysis to Automate OSS Security

Evaluating a single open source project is relatively straightforward. Evaluating every open source component across hundreds of applications is not.

As organizations increase their use of open source, dependency management becomes a core OSS security challenge. Security teams need visibility not only into direct dependencies selected by developers, but also into the transitive dependencies introduced throughout the software supply chain.

Software composition analysis (SCA) tools help organizations automate OSS security by continuously identifying:

• Open source vulnerabilities
• Transitive dependency risks
• License compliance concerns
• Outdated components
• Policy violations
• Component health indicators

Rather than relying on manual reviews, automated SCA solutions like Sonatype Lifecycle provides visibility into the open source components used throughout development and helps teams prioritize remediation efforts based on risk.

SBOMs and Software Supply Chain Security

Understanding exactly what components exist within your environment has become a foundational requirement for software supply chain security.

A software bill of materials (SBOM) provides visibility into what is inside your applications. Similar to an ingredient list for software, an SBOM inventories the open source and third-party components used within an application, along with their versions and dependency relationships.

This visibility becomes especially important when new vulnerabilities are disclosed. Organizations with accurate SBOMs can quickly determine whether they are affected, identify the applications at risk, and prioritize remediation efforts before vulnerabilities become incidents.

An SBOM helps organizations:

• Understand what components exist within an application.
• Identify exposure to newly disclosed vulnerabilities.
• Accelerate incident response.
• Improve software transparency.
• Support compliance and audit requirements.

However, generating an SBOM is only the first step. An SBOM provides a snapshot of what’s in an application at a specific point in time. To remain effective, that inventory must be paired with continuous monitoring and vulnerability intelligence as risks emerge and software evolves.

SBOM management solutions such as Sonatype SBOM Manager help organizations operationalize SBOMs, maintain visibility into software composition, assess software supply chain risk, and adhere to regulatory requirements.

OSS Security Best Practices for a Secure Software Development Lifecycle

Incorporating robust security measures into your SDLC isn’t just a best practice — it’s a necessity in today’s threat landscape. If your SDLC processes are firmly rooted in infosec best practices, you can significantly bolster your application and minimize risks of vulnerabilities and malware.

Consider the strategies below which can be augmented with Sonatype’s solutions:

• Strengthen your application’s defenses: Strengthen your application’s security by implementing best practices for writing clean and secure code. Prioritize readability and maintainability to reduce the possible introduction of vulnerabilities. Boost these efforts by automating your security processes with Sonatype Firewall, which enables early identification of vulnerabilities and blocks malicious components automatically.
• Advocate rigorous code review and testing: Instill a code review culture within your team with repeatable practices to proactively uncover security flaws. Incorporate diverse perspectives and expertise into the review process. Security testing tools and techniques normalize your analysis, help identify vulnerabilities, and enforce compliance with security standards. Streamline security endeavors with Sonatype Lifecycle to receive ongoing monitoring alerts for vulnerabilities on any component, and enforce custom policies tailored to your compliance goals.
• Prioritize dependency management: Recognize the pivotal role of streamlined management of software dependencies. Today’s software often hinges on a diverse array of open source libraries and components. Regularly scrutinize and update these dependencies with an SCA tool to preempt vulnerabilities stemming from outdated code. Stay vigilant about security advisories and patches. Sonatype Lifecycle enables you to know the location of each of your components and their dependencies, so you can quickly generate a software bill of materials (SBOM) for any application, both to provide full visibility of your application’s dependencies and to help efficiently remediate vulnerabilities as well.
• Extend your secure design principles to OSS components: Aligning your design decisions with security principles builds a foundation to defend against vulnerabilities throughout development. Apply these principles to your use of OSS as well. Sonatype Lifecycle makes this easier by offering real-time, data-driven insights into the security health of your software components, so you can ensure that you are using OSS components safely.

Building Confidence in the Security of Your OSS Use

OSS brings immense flexibility and collaborative potential to the table, yet it carries with it inherent complexities that demand careful attention — especially in the context of a software supply chain.

By implementing robust security measures in your SDLC, you can transform your software's security landscape:

• Shielding it from potential threats;
• Enhancing threat detection capabilities; and
• Proactively identifying vulnerabilities, while still reaping the benefits of OSS components.

Sonatype Firewall and Sonatype Lifecycle operate as potent allies in your quest for fortified security. Sonatype Firewall guards against vulnerabilities, preventing malicious components from infiltrating your systems. Sonatype Lifecycle serves as a comprehensive toolkit for ongoing monitoring, compliance enforcement, and visibility into your software components.

By fostering a culture of security awareness and embracing OSS security, you build not only stronger applications but inspire trust, resilience, and innovation. Ultimately, securing your use of the OSS ecosystem translates into safeguarding your product's future.

Written by Aaron Linskens
Aaron is a technical writer at Sonatype. He works at a crossroads of technical writing, developer advocacy, and information design. He aims to get developers and non-technical collaborators to work better together in solving problems and building software.