It is all about figuring out what will work best for your team's workflow

A typical and sometimes dreaded component of the development process is using a static code analysis tool. These days, from free, open-source tools to high-end commercial goods, there are so many options that deciding which one is best for your development team can be difficult.

We'll get to that later, but first, let's discuss the many sorts of application security testing tools available.

In this article

  1. What is Static Code Analysis?
  2. What is a static code analysis tool?
  3. The Differences between open-source and commercial SAST tools
  4. Using test projects to choose a SAST tool
  5. Making SAST tools work for your team

What is Static Code Analysis?

It is the process of scanning source code for vulnerabilities and flaws before running a program, usually with an automated tool.

What is a Static Code Analysis Tool?

For many years, static code analysis techniques have been available, often known as static application security testing - SAST tools. These tools are a sort of software that searches an application's source code and summaries any security issues before it is deployed in the field. Other automated security testing technologies, such as dynamic application security testing (DAST) and interactive application security testing, have emerged over time (IAST).

Using a combination of all of these technologies, according to Nicole Schwartz, a product manager specialized in application security testing at GitLab, a prominent code collaboration and DevOps platform, is often the best strategy. While SAST tools look for vulnerabilities in source code, DAST tools don't look at source code and instead run against live versions of programs. Adding an application security platform can unify these testing approaches, providing a centralized view of vulnerabilities to help teams address risks more efficiently.

"One of the best features of DAST is that it is language agnostic. It does, however, require an operating environment against which to hit."

Since SAST tools scan source code, they must be compatible with and built for the programming language used by the development team to create the scanned application. According to Schwartz, one advantage of this method is that SAST tools may pinpoint security vulnerabilities to individual lines of code, which can assist speed up the debugging and patching process.

Despite the differences between the SAST and DAST tools, combining their results in a more robust and secure application. Both SAST and DAST play a key role in formalizing DevSecOps to achieve software security testing at speed.

If you follow all of these phases in your software development process, you'll catch everything. If you only focus on one, even if you do it flawlessly, there will still be things that a SAST scanner or a DAST scanner won't catch.

Using the SAST and DAST tools in unison ensures a more secure application.

Additional great topics on software testing:

https://www.parasoft.com/solutions/application-security-testing/

https://www.parasoft.com/solutions/compliance/owasp/

https://www.parasoft.com/solutions/api-testing/

https://www.parasoft.com/blog/api-testing-guide/

https://www.parasoft.com/solutions/test-data-management/

https://www.parasoft.com/blog/what-is-service-virtualization/

https://www.parasoft.com/solutions/unit-testing/

The Contrasts between commercial SAST and open-source tools

When looking at the price for SAST tools, keep in mind how your development team is built and functions.

According to Schwartz, "certain tools charge by lines of code." "Other times, it's based on the number of developers you have."

On the other hand, companies may not always need to pay for SAST tools, especially at first.

"There are a lot of free scanners out there," Schwartz explained. "Start with that and show your management how valuable it is, then upsell it to a commercial tool because it will be more usable."

While many open-source SAST tools effectively detect vulnerabilities, she claims they fall short in terms of support and user experience.

"There are numerous free scanners available. Begin with that and demonstrate its worth to your boss."

A paid scanning tool will "probably just be a better-refined offering," according to Schwartz.

"Some of the more complex technologies that have assistance, they gather a load of information about your environment," she explained, allowing them to reduce the number of false positives reported based on relevance."Or maybe there's a bug in this dependency's function." It'll go through your entire code to see if you've ever used that function. If you didn't, don't worry about updating that dependence — open-source tools won't."

Particular tools can track how sections of your codebase interrelate

ShiftLeft gets its name from the concept of bringing security concerns earlier in the development lifecycle or "shifting left" in security parlance. This includes ShiftLeft, a corporation whose main product is a SAST tool. According to ShiftLeft's head of marketing, the company's tool works by merging graphs generated by an application's compiler that maps out the flow of the code (i.e.,the control flow graph).

ShiftLeft's SAST tool builds a composite graph that maps all conceivable paths across a given application, allowing the tool to check that all relevant security protections are present along each route, according to Fife.

According to Arun Balakrishnan, ShiftLeft's director of products, the ShiftLeft tool searches for "whether something is traveling from point A to point C without going through a point B, which is a check that you do." If no point B can be discovered, the route is vulnerable to a security breach.

"If this then translates to the database," he explained, "it's a potential SQL injection." "You may have a string with HTML content in it, and that's when cross-site scripting happens." It could be a remote code execution if the string has a path and ends up in the system command. These are all common vulnerabilities in web applications."

The composite graph also allows users to construct their custom queries to execute on the graph or utilize ShiftLeft's templated queries.

Paid tools like ShiftLeft, according to Schwartz, are sometimes able to catch more flaws by looking at problems in the way different pieces of code interact, rather than only looking at isolated chunks of code for vulnerabilities.

"If you have two items on their own, they might not be harmful," she explained. "However, if you chain them together, there's a good chance something will go wrong."

Scans that look at code interactions can uncover more flaws.

Using test projects to choose a SAST tool

GitLab, according to Schwartz, sometimes runs several SAST tools against test projects to determine which tools to keep. This technique can also be useful for development teams looking for an early SAST tool.

"Every now and then, we'll take test projects and run a bunch of open-source scanners to observe the one that is highly performant as well as finds the most bugs," Schwartz explained. "We might re-benchmark if something fresh comes out on the market."

The GitLab team evaluates features such as scanning speed, the quantity of false positives, and the tool's ability to detect more vulnerabilities. They switch to a new tool if it performs better against their benchmarks than the one they were previously using.

According to Schwartz, there are ready-made test projects available online for organizations that don't have test projects on hand.

"We'll take test projects and run a lot of open-source scanners to see which one is the fastest and finds the most bugs."

"There are purposely weak code projects out there," she noted. She cited the Juice Shop and WebGoat apps as examples, both mock websites maintained by the Open Web Application Security Project community—designed to showcase typical security flaws.

However, because the programming language is vital for SAST tools, choosing a test project written in the same language as your code is critical. Otherwise, test results might not indicate the SAST tool's suitability for your application.

Making SAST tools work for your team

Choosing a SAST tool that integrates effectively with a development team's workflow is also contingent on making the decision. It's critical, according to Schwartz, to include developer feedback in the decision-making process.

"In an ideal scenario," Schwartz added, "you'd have one person on the engineering team who understands how the security team works." "And they could say, 'I'd like to utilize this technology because of the way my team operates.' Unfortunately, there aren't many engineers who are passionate about security or are interested in it. So the security team tells engineering, 'Hey, you have to utilize this.'And that's fine occasionally, but a lot of the time, the security guys don't understand the development workflow, and so [the developers] are suddenly required to do all this implementation and other insane work, which disrupts their workflow and causes problems."

Developers that consider SAST to be their least favorite four-letter word frequently complain that they're flooded with alerts that, upon closer analysis, aren't true vulnerabilities.

"Unfortunately, all of the tools have a high false-positive rate," Schwartz said. Doing risk analysis and prioritizing sections of the program that are most vulnerable to threats is one approach to avoid wasting development time running after alerts all of the time.

"It's like, I have a login page here, and I save customer information in this database." "These are the two places where I'm taking a chance," she explained. "You can say, 'I don't want to scan any areas of my application except the login page and the sites that allow me to view customer information or personally identifiable information.' So you're now disregarding a whole bunch of portions of your code about which you don't care if it's breached because you're going to deprioritize them.

"How DevOps is designed also influences whether or not using the SAST tool will be easy to integrate into the development cycle or cumbersome.

"Probably the most significant thing is your workflow as an engineering team," Schwartz said, "and where you could place a scan that would be the least uncomfortable for you and most useful." "It's a delicate balancing act." "Scanning all the time wastes a lot of time and resources."

She emphasized the necessity of being vigilant when looking for security weaknesses in programming. She stated that the Heartbleed Bug, which affected most websites employing the secure HTTPS protocol and was identified in the OpenSSL protocol, was the product of a single developer's error.