Application security has become a top priority for developers and organizations alike. However, determining the best approach to guarantee software security can be a complex process. Two leading methodologies that have surfaced in recent years are Software Composition Analysis (SCA) and Static Application Security Testing (SAST).
While both of these techniques play crucial roles in the development and security lifecycles, their unique characteristics make them suitable for different scenarios. This article explores both SCA and SAST, highlighting their key differences, when to choose one over the other, and how to use them together for a holistic security strategy. We hope these insights will help you make your software resilient to ever-evolving cyber threats.
What is Software Composition Analysis?
Software Composition Analysis, or SCA, is an approach used in the field of software development to manage and analyze the components of a software system. It deals primarily with the identification of open-source components, their versions, and their interrelationships. This process is crucial for managing vulnerabilities, licensing, and maintaining the overall security of a software system.
SCA tools are designed to scan the software codebase and identify open-source components, third-party components, and any associated licenses. They create a ‘Bill of Materials’ (BOM) that lists all of these components and their corresponding metadata. This comprehensive list aids in managing the diverse elements that make up a software system and ensures that they comply with the organization’s policies and legal requirements.
Software Composition Analysis is becoming more important in today’s IT environment, where open-source components constitute a significant portion of any software product. It allows developers to leverage the benefits of open-source software while mitigating the associated risks.
What is SAST?
Static Application Security Testing (SAST) is a white-box method of testing, where the tester has knowledge about the system under test. It involves analyzing the source code, bytecode, or binary code of an application to identify potential security vulnerabilities that can be exploited by attackers.
SAST is typically performed early in the software development lifecycle (SDLC) and can be integrated seamlessly into the development pipeline. It provides immediate feedback to developers about potential vulnerabilities in their code, allowing them to address these issues promptly.
The primary strength of SAST lies in its ability to analyze the entire codebase and find common coding mistakes that can lead to security vulnerabilities. It can identify issues like SQL injection, cross-site scripting (XSS), and buffer overflow, among others.
Software Composition Analysis vs. SAST: 5 Key Differences
While both SCA and SAST are important tools for managing software security, they serve different purposes and have unique characteristics. Let’s delve into the key differences between these two approaches.
1. Scope of Analysis
The primary difference between SCA and SAST lies in their scope of analysis. SCA focuses on identifying and managing open-source components in a software system. It helps manage the licenses associated with these components and identify potential vulnerabilities in them. On the other hand, SAST analyzes the entire codebase, including proprietary code, to identify potential security vulnerabilities.
2. Detection of Vulnerabilities
In terms of vulnerability detection, SCA relies on databases that contain known vulnerabilities in open-source components. It matches the components in the software system with these databases to identify potential risks. SAST, however, uses static analysis techniques to identify potential vulnerabilities in the code, regardless of whether they are known or not.
3. Point of Integration
SCA and SAST also differ in terms of their integration into the development lifecycle. SCA is typically integrated later in the SDLC, during the testing or deployment phase. This is because it requires a complete list of components, which is usually only available towards the end of the development process. On the contrary, SAST is integrated early in the SDLC, often during the coding phase. This allows developers to fix potential vulnerabilities as they write the code.
4. Time to Remediate
The time taken to remediate vulnerabilities also varies between SCA and SAST. Since SCA relies on known vulnerabilities, the remediation process often involves updating the component to a version that does not contain the vulnerability. This can usually be done quickly. SAST, however, requires more time for remediation. Since it identifies potential vulnerabilities in the code, developers need to understand the issue and modify their code to fix it.
5. Handling of False Positives
Finally, SCA and SAST differ in their handling of false positives. False positives refer to instances where the tool identifies a potential vulnerability, but it turns out to be a non-issue. SCA typically has fewer false positives since it relies on known vulnerabilities. SAST, however, can have more false positives, as it uses static analysis techniques that can sometimes misinterpret the code.
When to Choose SCA?
Projects with Extensive Use of Open Source
SCA is particularly beneficial for projects that heavily rely on open-source software. Open-source software is essentially a type of software whose source code is freely available to the public and can be modified or distributed without any restrictions. However, this freedom does come with certain risks, primarily in the form of vulnerabilities that malevolent actors might exploit.
Software Composition Analysis tools help identify these vulnerabilities by scanning the open-source components and checking them against known vulnerability databases. By doing so, they provide a clear insight into the security status of the software, which can then be used to take appropriate remedial actions. This makes SCA an invaluable tool for projects that heavily rely on open-source software.
Another area where SCA shines is license compliance. Open source software comes with a variety of licenses, each with its own set of obligations and restrictions. Non-compliance with these licenses can lead to severe legal consequences, including hefty fines and tarnished reputation.
Software Composition Analysis tools can help avoid such scenarios by providing a comprehensive overview of all the licenses associated with the open-source components used in a project. They can also highlight any potential licensing conflicts, thereby allowing the developers to address these issues proactively.
The quick remediation of vulnerabilities is another reason to choose SCA. Once a vulnerability is detected, it is essential to address it as quickly as possible to prevent it from being exploited. Software Composition Analysis tools not only help identify vulnerabilities but also suggest remediation paths.
This approach not only saves time but also ensures that the chosen remediation path is effective and does not introduce new vulnerabilities. It also allows developers to focus on their core tasks, thereby improving the overall efficiency and productivity of the project.
When to Choose SAST
Custom Code Projects
While SCA is excellent for open-source heavy projects, Static Application Security Testing (SAST) is a better choice for projects involving custom code. Custom code is more susceptible to vulnerabilities as it is developed from scratch and may not follow secure coding practices.
SAST tools help identify these vulnerabilities by analyzing the source code without actually executing it. They do so by building a model of the application’s code and using this model to identify areas where the code deviates from secure coding practices. This makes SAST an ideal choice for projects involving custom code.
Early Error Detection
Another advantage of SAST is its ability to detect errors early in the development lifecycle. Since SAST tools analyze the source code, they can identify vulnerabilities during the coding phase itself, well before the software goes into the testing or deployment phases.
Early detection of vulnerabilities not only saves time and resources but also reduces the risk of a security breach. It also instills a culture of secure coding among the developers, as they get immediate feedback on their coding practices.
Finally, SAST tools can help enforce coding standards across the project. Coding standards are essential for maintaining the quality and consistency of the code. They also play a crucial role in preventing vulnerabilities as they mandate the use of secure coding practices.
SAST tools can enforce these standards by flagging any deviations and suggesting corrections. This not only ensures that the code follows the prescribed standards but also helps inculcate a habit of secure coding among the developers.
Combining SCA and SAST for a Comprehensive Security Strategy
While both SCA and SAST have their strengths, they are not mutually exclusive. In fact, combining them can result in a comprehensive security strategy that covers all aspects of software security.
SCA can handle the open-source components, ensuring that they are free from known vulnerabilities and license issues, while SAST can take care of the custom code, ensuring that it adheres to secure coding practices and is free from potential vulnerabilities.
In conclusion, by choosing the right tool for the right project and combining them when necessary, you can ensure a robust and comprehensive application security strategy.
Author Bio: Gilad David Maayan
Gilad David Maayan is a technology writer who has worked with over 150 technology companies including SAP, Imperva, Samsung NEXT, NetApp and Check Point, producing technical and thought leadership content that elucidates technical solutions for developers and IT leadership. Today he heads Agile SEO, the leading marketing agency in the technology industry.