SCA Vs. SAST: Everything You Need to Know

Security bugs and flaws are common in software applications. No matter how well the developers follow the security guidelines and write the code, the final result will have some security issues.

To make this worse, malicious users are ready with their exploitation scripts everywhere on the web. Sometimes they are easy to detect with the help of firewalls and intrusion detection systems, but most of the time they are undetectable. They attack software applications every day to steal crucial information and user data. In other words, the attackers are potentially watching anyone on the web— waiting for the perfect opportunity to slide in and make their move.

This is why an array of application security testing tools are available to help organizations address security risks.

In this article, we'll be talking about two major application security tools— SAST and SCA and if we can combine both for a better testing process. Both these methods come under the umbrella term Application Security Testing (or AST for short), and so before diving into them, let's talk about application security testing and its benefits.

What is Application Security Testing?

Application Security Testing (AST) is the process of making applications more resistant to security threats using tools and practices that allow the developers to detect and fix all the vulnerabilities in the codebase.

Due to the complexity of modern web applications, developers require multiple vulnerability detection tools that rely on various testing methodologies. Some tools can detect the common problems in the codebase, some do dynamic testing on already running deployments, and some identify the open-source software in the codebase to check license compliance and known vulnerabilities.

Benefits of Application Security Testing

To help the developers maintain a secure codebase, various types of security testing are required throughout the different stages to secure the Software Development Life Cycle (SDLC). Below are the reasons why organizations need to invest in application security

Protect against External Attacks: Security testing reduces the risk of attacks by reflecting all the errors in the codebase during testing and then fixing them.

Reduces Intrinsic Business Risk: With security testing, the developers test the software on every ground, highlight all the bugs and fix them so that the end user's data can stay safe. If the software's security is improper, it could affect the organization's reputation, and as a result, the whole business could come at risk.

Cost Savings: performing security testing during SDLC saves costs by detecting bugs early. After detection, developers fix all the issues instantly, and this, in turn, saves both time and money.

Increases Demand: If the software is well maintained and up-to-date with security patches, it will enable security to be a competitive advantage for the business. Positive user experiences, ratings, and reviews will be in order, which will increase the demand for the software.

SAST and SCA are the two most popular application security testing tools. Now to identify which one you need or how to combine both for better results, it's imperative to understand what these are and how they are beneficial for your application.

What is SAST?

Static Application Security Testing (SAST), also known as static analysis, is a structural testing methodology that analyzes source code to pinpoint security vulnerabilities that makes the application susceptible to attacks. It scans an application before the code is compiled and is known as white box testing.

Why is SAST important?

SAST takes place during the early stage of the SDLC as it doesn't require a working application but can take place even without the code being executed. It allows the developers to detect bugs and vulnerabilities during the initial stages of the development process and resolve issues without breaking builds or passing on bugs to the final version of the application.

SAST tools provide developers with real-time feedback as they code, allowing them to fix the errors before passing the code to the next stage of the SDLC. SAST tools also show graphical representations of the issues found, from source to sink. With these representations, it becomes easier to navigate the code. Some tools also show the exact location of the vulnerabilities and highlight the issues. Further, these tools can also provide in-depth guidance on how to fix the issues and the best place in the code to fix them without requiring deep knowledge of the security domain.

With the help of SAST tools, developers can also create customized reports and export them offline. Tracking all the security issues using a tool in an organized way allows developers to remediate the issues promptly and release the application with the least issues.

What is SCA?

Software development today relies heavily on the use of open-source components and frameworks. And while open-source components can help to speed up the development process, they can also lead to vulnerabilities if the developers don't audit all the code snippets as well as libraries or components that are outside of the code base.

Software composition analysis (SCA) is an automated process that tracks all the open-source components in an application's codebase. This analysis allows developers to evaluate the security, license compliance, and code quality of these open-source components.

Why is SCA important?

Manual tracking of open-source code in a codebase is no longer viable; it can't keep up with the huge amount of open-source code. And the increasing prevalence of cloud-native and more complex applications makes the use of SCA tools essential.

With the development speed fastening due to the adoption of DevSecOps methodologies, organizations need security solutions that can cope with the development speed, and that's why SCA tools have become a necessity.

While SCA and SAST, both have their advantages, there are a few key differences between them that can help you understand which one is right for you.

SAST Vs. SCA Testing: The Key Differences

Now that we know what is SAST and SCA and why they are important for choosing the right option for your application, it’s crucial to understand the key differences.

On checking the differences, you’ll be able to identify which testing tool is appropriate for your application and its security. Here are the key differences between SCA and SAST.

Vulnerability Detection

While SAST tools can scan an organization's application's codebase for potential vulnerabilities based on a set of predetermined rules, SCA focuses on identifying the open-source codebase so the developers can manage their exposure to vulnerabilities and license compliance issues.

Source Code Access

SAST tools focus specifically on the source code to detect vulnerabilities. This means they will need access to the source code to scan it. On the other hand, SCA tools discover all open-source software components, including their supporting libraries, which are the direct and indirect dependencies. This process doesn't require giving source-code access to the SCA tools.

SDLC Integration

SAST and SCA tools can be integrated during the early stage of the SDLC and help the developers track vulnerabilities at the earliest and, in turn, save time and resources. Both SCA and SAST tools integrate with CI servers and IDEs. However, SCA offers end-to-end SDLC coverage of the open-source components all the way to post-development— offering coverage for vulnerabilities found in these open-source components even after years of release.

False Positives

If the code is improperly configured, SAST tools will detect a high number of false positives in the source code. In contrast, SCA tools are known for their faster working speed, are suitable for releasing early and often and have low false rates for open-source codes.

Timeframe

Running open-source code scans using SAST tools (SAST tools can be used to scan both, source code and open-source code) is often time-consuming; sometimes, it takes hours. However, as aforementioned, SCA tools run within seconds, no matter how large the codebase is.

Applciation Coverage

Developers often mistake the higher volume of security vulnerabilities flagged by SAST to mean that it offers better code coverage. However, SAST tools only cover the code written by development teams themselves which makes up for as little as 10-30% of the final application, with the rest being from open-source components that can only be scanned using SCA.

Exploitability

Given their static nature, both SAST and SCA tools are unable to clearly define the real-world exploitability risk of the vulnerabilities that they detect. However, SCA tools detect open-source known vulnerabilities which tend to be more commonly exploitable given their public disclosures and readily available exploit information.

Risk Coverage

SAST tools can detect various potential code flaws, known as CWEs. Some of the most common CWEs are listed in lists like OWASP Top 10 and MITRE Top 25. All these flaws are security risks in the application. On the other hand, SCA tools can identify both security and license compliance risks associated with open-source software.

By now, you must have understood which one is more suitable for you - SAST or SCA, or if you can utilize both of these to make your application fully secure. Thankfully, you can combine both and ensure that the application doesn't have any vulnerabilities at the time of its launch.

Combining SAST and SCA for Better Application Security

When looking at these two technologies together, it becomes clear that both of these are required to build a secure application. So the best option here is to combine both tools.

While combining these two can be quite challenging, with the right approach and the knowledge of how to do it properly, it can be done smoothly. Here are a few ways to perform it smoothly:

Use the DevSecOps Model

Developers can follow the DevSecOps model while using SAST and SCA to mitigate vulnerabilities by implementing both tools and approaches at every stage of the development process. To begin, they should introduce SAST and SCA tools to the developers as early as possible. Specifically, the tools should be introduced during the coding phase— the time during which the code is being written for the application.

Integrate SAST and SCA Into the CI/CD Pipeline

Another way of combining SCA and SAST tools is by integrating them into CI/CD pipeline. CI stands for continuous integration and refers to a software development approach where the developers combine code changes in a centralized hub multiple times a day. CD, continuous delivery, then automates the software release process.

Create a Consolidated Workflow with SAST and SCA

The final way to use SAST and SCA is by creating a consolidated workflow. To do this, the developers would need to purchase some cutting-edge cybersecurity tools that allow teams to conduct SAST and SCA scanning simultaneously. This, in turn, helps the developers save time and effort.

Scantist has an SCA tool that is completely free to use - and you can try it now!