Open Source Security: Threats, Technologies, and Best Practices

What Is Open Source Security?

Open source security refers to methods and practices to protect open source software, and closed source software solutions that incorporate open source components, from security vulnerabilities. It involves identifying, managing, and mitigating risks associated with the use of open source. Open source software creates unique risks, because its code is publicly available and vulnerabilities can be more easily exploited by malicious actors. 

Ensuring security involves regular checks, updates, and compliance with best practices to preempt and respond to security threats. Open source security is growing in importance because of the growing use of open source components in enterprise applications across industries.

Open source security includes both defensive measures, like vulnerability scanning and monitoring, and legal measures, such as compliance with licensing terms to ensure these components remain safely integrated within systems.

Why Is Open Source Security So Important?

Open source security is critical due to the widespread use of open source software in modern applications. According to the Linux Foundation Census III report, there are over 12 million observations of free and open source software (FOSS) libraries in production applications across more than 10,000 companies. 

However, much of the most widely used FOSS is maintained by only a handful of contributors, making it vulnerable to security risks if those contributors fail to address critical vulnerabilities. Additionally, the decentralized nature of open source makes it difficult to centrally measure and secure all dependencies, increasing the risk of unpatched vulnerabilities being exploited.

Globally, open source attacks have been on the rise, targeting both individual projects and entire software supply chains. The report highlights that attackers actively exploit vulnerabilities in FOSS, with supply chain security becoming a major concern. For example, the Log4j vulnerability exposed millions of systems to remote code execution attacks, demonstrating how a flaw in a single open source library can have global consequences.

Common Open Source Security Risks 

Unpatched Vulnerabilities

Unpatched vulnerabilities occur when open source components are not updated to address known security flaws. Attackers actively monitor vulnerability disclosures, looking for opportunities to exploit software that remains unpatched. This is especially risky for widely used libraries, as even a single unpatched vulnerability can impact thousands of systems. 

Dependency Chains

Open source software often depends on other libraries to function, creating extensive dependency chains. These chains can be difficult to manage, as vulnerabilities in a low-level or indirect dependency may be unknown to the organization using the software. For example, a library might rely on an older, insecure version of another library, exposing the entire application to risk. Since many dependencies are nested or hidden, these risks are hard to detect manually. 

Abandoned or Unmaintained Projects

Open source projects often rely on volunteer contributors or small teams, which means that some projects may eventually be abandoned or become inactive. If a project is no longer maintained, security vulnerabilities remain unpatched, and users may not be alerted to emerging risks. 

Malicious Code Injections

Malicious code injections happen when attackers introduce harmful code into open source repositories or packages, often through compromised contributor accounts, malicious pull requests, or by gaining control of a project. Once integrated, this code can execute harmful actions such as stealing sensitive data, opening backdoors, or installing malware on systems using the library. 

Typosquatting and Malicious Package Names

Typosquatting attacks exploit common typing errors by creating malicious packages with names similar to legitimate ones. For example, a malicious package named "numpi" might trick developers intending to download "numpy." Once installed, these packages can introduce backdoors or exfiltrate sensitive information.

License Mismanagement

Open source components come with varying licenses that dictate usage, modification, and distribution rights. Failing to comply with these licenses can lead to lawsuits, financial penalties, or forced disclosure of proprietary code if a license requires it (e.g., copyleft licenses like GNU General Public License). Mismanagement can also create compliance risks during mergers, acquisitions, or software audits. 

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Identifying and Managing Open Source Vulnerabilities

Several common measures are used to manage the security risks associated with open source software. 

Using Software Composition Analysis Tools 

Software composition analysis (SCA) tools assist in managing open source security by identifying vulnerabilities in third-party libraries and dependencies. Traditional SCA tools scan codebases to detect outdated or vulnerable components, but real-time SCA solutions go further by monitoring the behavior of a running application. This helps distinguish between theoretical risks and actual threats by identifying which vulnerable functions are executed within an application.

Advanced real-time SCA solutions provide deep visibility into how libraries and dependencies interact down to the function level. These tools detect vulnerabilities and assess their real-world exploitability, allowing security teams to focus on high-risk issues. 

Implementing Software Bill of Materials (SBOMs)

A software bill of materials (SBOM) lists all components within a software product, detailing each component’s origin, version, and known vulnerabilities. SBOMs improve transparency and enable more effective vulnerability management by providing a clear overview of all elements in use. This documentation assists in faster identification of affected parts if a vulnerability arises.

SBOMs also ensure better compliance with licensing requirements, reducing the risk of non-compliance. Maintaining an accurate and up-to-date SBOM allows organizations to respond efficiently to security incidents, simplifying vulnerability management processes. Implementing SBOMs as part of standard security protocol reinforces preparedness against security threats.

Using Open Source Vulnerability Scanners

Open source vulnerability scanners identify security flaws in open source components. They analyze software dependencies, compare them against known vulnerability databases like the National Vulnerability Database (NVD), and provide actionable insights to remediate risks. By automating the detection process, they reduce the effort needed to find vulnerabilities.

To maximize the effectiveness of vulnerability scanners, organizations should integrate them into the software development lifecycle, including during code commits, builds, and deployments. This ensures continuous monitoring and reduces the risk of introducing vulnerabilities into production systems.

7 Best Practices for Securing Open Source Software

Organizations should implement the following best practices to ensure the security of any software that incorporates open source components.

1. Maintain an Accurate Inventory of Open Source Components

Keeping a detailed inventory of open source components used in projects is essential for security. This inventory includes information about component versions, licenses, and any known vulnerabilities. Having this visibility helps in managing updates and patches effectively.

An accurate inventory also aids in maintaining compliance with open source licenses, avoiding legal complications. Regular updates of the inventory ensure it reflects the current state of all dependencies, enabling proactive actions against emerging vulnerabilities. Maintaining this inventory aids in sustaining security in environments that leverage open source software.

2. Continuously monitor open source dependencies for vulnerabilities and security risks

The most foolproof way to deal with the challenge of securing open source software is to continuously monitor what open source libraries are actively being used and check them against known (and even unknown) security risks. With the rate at which vulnerabilities are disclosed for open source software, understanding which libraries are being actively being run versus those that aren’t even used drastically reduces the backlog of security risks for developers to act on.

3. Regularly Update and Patch Open Source Dependencies

When open source libraries are being used and are vulnerable, updating and patching them regularly is crucial to mitigating potential security risks. Security analysts and developers must consistently monitor for updates and implement patches that address known vulnerabilities or implement other mitigating controls when no patch is available. Staying current with updates ensures that systems benefit from the latest security and feature improvements offered by the community.

4. Conduct Security Assessments of Open Source Software

Conducting regular security assessments helps identify potential vulnerabilities in both proprietary and open source software components. These assessments involve code reviews, penetration testing, and static analysis to detect weak points before they can be exploited. Proactively assessing the security posture allows teams to fix issues before they escalate.

Assessments also enable a deeper understanding of the software environment, guiding informed decisions about integrating open source tools. By regularly evaluating the security of open source software, organizations can adapt their strategies to evolving threats and bolster their overall security framework.

5. Enforce License Compliance and Governance

Organizations must implement governance frameworks to oversee license management, ensuring adherence to legal requirements. This can prevent costly legal challenges and maintain integrity in software operations. Creating a licensing policy detailing acceptable use and distribution guidelines helps mitigate risks.

Effective license governance involves training team members on compliance essentials, auditing software assets, and consistently updating policies as licenses evolve. These practices embed compliance awareness into the organizational culture, protecting against inadvertent license breaches and ensuring sustainable use of open source software within legal bounds.

6. Implement Secure Coding Practices

Secure coding practices are essential to developing safe open source software. Developers must adhere to coding standards that prioritize security, such as input validation and secure error handling. These practices minimize vulnerabilities, reducing the likelihood of exploitation. Continuous education on secure coding helps keep developers informed about new threats and mitigation strategies.

Adopting industry-recognized coding frameworks and guidelines, such as OWASP, improves software reliability. Secure coding extends beyond initial development, requiring ongoing evaluations to adapt to evolving cybersecurity landscapes. Implementing these practices cultivates a proactive security posture, helping protect open source solutions against attacks.

7. Move From Reachability to Exploitability

Many tools that help with open source security include reachability analysis, which is the ability to estimate the likelihood that an open source component will be run when the application is in production. 

Advanced SCA tools go beyond reachability and use deterministic analysis to identify exploitability. Exploitability monitors the behavior of the running application and determines with certainty whether a vulnerable open source component is present in an application, and layers on several other risk factors (business criticality, internet, exposure, and more).

This level of visibility simplifies open source security processes and separates signal from noise, as the rate of security risks with open source software continues to grow.

Open Source Security with Oligo

Developers push back when security findings seem untrustworthy, excessive, or lacking actual context of running applications. With Oligo, security and developers can see the actual components running in their applications, including full call stacks and root cause analysis to understand exactly which open source security vulnerabilities need to be addressed first. 

Learn more about our approach to open source security.