SAST – All About Static Application Security Testing


Static Application Security Testing (SAST) has been a central part of application security efforts for over 15 years . Forrester’s State Of Application Security Report, 2021 found that lacking application security remains top cause of external security breaches, so it’s safe to say that SAST will be in use for the foreseeable future.

What Is SAST?

Static application security testing (SAST), one of the most mature application security testing methods in use, is white-box testing, where source code is analyzed from the inside out while components are at rest. Gartner’s definition of SAST is “a set of technologies designed to analyze application source code, byte code and binaries for coding and design conditions that are indicative of security vulnerabilities.”


Mend SAST.

Security at the Speed of DevOps


Why do we need SAST?

According to the Forrester report, a survey of security professionals showed that over two-thirds of external attacks in 2020 were carried out either through a web application (39%), or by exploiting a software vulnerability (30%) . SAST has become synonymous with application security testing tools, but if we really want to ensure our software is secure, it’s important to know how the tools we use work. 

This is part of an extensive series of guides about security tensing


What Problems Does SAST Address? 

SAST enables developers to detect security flaws or “weaknesses” in their custom source code. The objective is either to comply with a requirement or regulation (for example, PCI/DSS) or to achieve better understanding of one’s software risk. Understanding security flaws is the first step toward remediating security flaws and thus reducing software risk. 


How Does SAST Work?

As its name implies, SAST scans organizations’ static in-house code at rest, without having to run it. SAST is usually implemented at the coding and testing stages of development, integrating into CI servers and, more recently, into IDEs. 

SAST scans are based on a set of predetermined rules that define the coding errors in the source code that need to be addressed and assessed. SAST scans can be designed to identify some of the most common security vulnerabilities out there, like SQL injection, input validation, stack buffer overflows, and more. 


What new tools can be used for SAST?

A new generation of  SAST solutions lets enterprise application developers create new applications quickly, without sacrificing security. They aim to integrate with your existing DevOps environment and CI/CD pipeline, so developers don’t need to separately configure or trigger the scan. They expedite the SAST process, while supporting multiple programming languages and various different programming frameworks.

Modern SAST tools that include these capabilities increase efficiency and convenience for developers. They make it quicker and easier to detect vulnerabilities, and they ensure compliance and reinforce governance. As a result, developers will learn to trust their software tools and collaborate more readily with members of the security team. 


Typical SAST Benefits

SAST is a top application security tool and, when done right, is essential to organizations’ AppSec strategy. Integrating SAST into the SDLC will improve your organization’s security profile because it provides the following benefits:. 

#1 Shifting security left

Integrating security testing into the earliest stages of software development is an important practice. SAST helps shift security testing left, detecting vulnerabilities in proprietary code in the design stage when they are relatively easy to resolve. Finding and remediating security issues at this stage saves organizations the costly efforts of addressing them closer to the release date or, even worse, after release. 

#2 Ensuring secure coding

SAST easily detects flaws that are a result of fairly simple coding errors, helping development teams make sure that they comply with secure coding standards and best practices. 

#3 Detecting common vulnerabilities

Automated SAST tools can easily detect common security vulnerabilities like buffer overflows, SQL Injection, cross-site scripting, and more with high confidence.


Enhanced Benefits of Next-Generation SAST 

SAST is a mature technology. Since its introduction,  the application development environment has changed. The new generation of SAST products, led by Mend, is evolving SAST in response to these changes, particualarly the scale and rapidity of the modern environment . This evolution offers the following additional benefits that enhance those offered by previous SAST products:

#1 Ease of use

The new approach to SAST further integrates it with your existing DevOps environment and CI/CD pipeline, so developers don’t need to separately configure or trigger scans. This removes the need for them to leave their development environment to run scans, view results, and research how to fix security problems. It’s more efficient, convenient and easier for them to use. This ease of use encourages increased use within developers’ workflow, further shifting security left, and making security more robust. It makes security a tool that developers more actively want to use.

#2 Comprehesive CWE coverage 

The comprehensive detection provided by Mend SAST will ensure that you have visibility to over 70 CWE types — including OWASP Top 10 and SANS 25 — in desktop, web and mobile applications developed on various platforms and frameworks. Advanced SAST supports multiple programming languages and various different programming framework. For example, Mend SAST supports 27 different languages. This enables more comprehensive vulnerability detection, and increases the visibility to a larger number of CWE types. 

#3 Overcoming false positives and eliminating wasteful effort

SAST products typically generated  a high number of false positives, costing development and security teams a lot of time and effort weeding out the false alarms in search of the real issues. Considering the competitive pace of development and the amount of time it takes to remediate critical issues, dealing with the noise of false positives put quite a strain on development. Now, Mend has a patented set of analytics that enables teams to signficantly reduce the generation of false positives, and eliminate the identification of a vast majority of open source application vulnerabilities that they would otherwise have to sift through, and address unnecessarily.

#4 Speed

Traditional SAST solutions were designed for an earlier era, when the typical SDLC took considerably longer than it now does, and one scan could take several hours for a large codebase. In today’s fast-paced development environment, where the duration of a release cycle is less than a day, these products are a poor fit.  Numerous research studies have shown that many developers simply don’t use the application security tools that their security team provide, because they choose speed over security. The new Mend SAST has a scan engine that is 10 times faster than traditional SAST products, so your engineers will get results in minutes or less.   


How to Choose the Right SAST Tool for Your Organization

The AST market is full of SAST offerings, often bundled up with additional solutions, making it a challenge to find the right fit for your organization. 

OWASP’s list of criteria for selecting the right SAST tools can help companies narrow down the options and choose the solution that best helps them improve their AppSec strategies: 

Language support: A top consideration is which languages your organization uses. Make sure the SAST tool that you use offers you complete coverage for those languages.  

Vulnerabilities coverage: Make sure that your SAST tool covers at least all of OWASP’s Top Ten web application security vulnerabilities. 

Accuracy: Your SAST solution should be capable of minimizing the false positives and false negatives that create unnecessary work. So, it’s important to check the accuracy of the SAST tools that your organization is considering. 

Compatibility: Like any automated tool, it’s important that the SAST tool you use is supported by the frameworks you are already using so that it integrates easily into your SDLC. 

IDE integration: A SAST tool that can be integrated into your IDE will save you valuable remediation resources. 

Easy integration: Find the SAST tool that is easy to set up and integrates as seamlessly as possible with the rest of the tools in your DevOps pipeline

Scalability: Make sure the SAST tool you integrate today can be scaled to support more developers and projects tomorrow. A SAST tool can seem to scan quickly on a small sample project; make sure it delivers similar results on larger projects. 

Rising scale can also impact the cost of the solution. OWASP’s list points out that it’s important to consider whether the cost varies per user, per organization, per application, or per line of code analyzed. 


How to Implement SAST

Having chosen your SAST solution, it’s important to implement it correctly in order to optimize its effectiveness and maximize the benefits you get from it. Successfully achieving this involves following this process:

  • Select the means of deployment. Decide whether you will deploy SAST on-premises or on the Cloud. This consideration depends on how much control you wish to have, how quickly, how easily and and how much you might wish to scale up.
  • Configure and integrate into your SDLC. Considerations here include when and how you scan and analyze your code. You can elect to:
    • Analyze code as it’s compiled
    • Scan it as you merge it into your code base
    • Add SAST in your CI/CD pipeline
    • Run SAST in your IDE, enabling developers to detect and mitigate vulnerabilities as they code
  • Choose the extent of your analysis. You can decide between the following:
    • Complete: A full scan of your applications and their code. Is the most comprehensive and most lengthy
    • Incremental: Scan only new or changed code
    • Desktop: Code scanned as it’s written. Issues addressed in real time
    • Without Build: Analysis in the source code, for those not familiar with the building process or the IDE

Customize it to suit your needs. You might want to focusing on reducing false positives, creating new rules or revising old ones in order to identify new security flaws. Perhaps you want to create dashboards for analyzing scans, or build custom reports.

  • Proritize applications and results, based on what’s most important to you. Considerations include compliance issues, severity of threat, CWE, risk level, responsiblity, status of the vulnerability
  • Analyze results, track progress and evaluate urgency. Examine scan results to remove false positives. Set up a system that automatically sends issues to the developers responsible, and then assign them to be addressed
  • Report and governance. Use either built-in reporting tools (e.g. OWASP Top 10 violations) or push data to other reporting tools you already have. Ensure that development teams are using the scanning tools properly.


SAST: An Important Component in Your Application Security Journey

Using traditional SAST products to ensure security in application development requires a value tradeoff. And that tradeoff is speed. SAST offers high value when it comes to coverage and visibility over an organization’s static codebase. It also integrates early in the SDLC, enabling organizations to shift security left. But, traditional solutions presented major barriers to agility.

The next generation of SAST overcomes these barriers, to meet the demand of today’s rapid SDLC.  As the SDLC becomes shorter and shorter, and as ever more applications are developed, so the attack surface grows, and the risk to the application layer continuously rises. However, now, the need to make such a value tradeoff is significantly reduced. 

Integrating SAST demands organizations strive to find the right balance between covering all security vulnerabilities and minimizing risk, and delivering quality products at a competitive speed.  Now development teams can more confidently combine security and speed earlier than ever in the development process.



See Our Additional Guides on Key Security Testing Topics

Together with our content partners, we have authored in-depth guides on several other topics that can also be useful as you explore the world of security testing.

Application Security

Vulnerability Management

Cloud Native Security

Authored by Tigera

Meet The Author

Ayala Goldstein

Ayala Goldstein is a writer at Mend. She writes about everything open source, AppSec, and DevOps.

Subscribe to Our Blog