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Demystifying SAST

Shobhit Mehta


April 16, 2024

Experts estimate that by 2026, software supply chain attacks could cause damages of $80.6 billion (globally) to businesses. The cost will rise even further to $138 billion by 2031, a 3X increase from the $45.8 billion that businesses lost to such attacks in 2023. These increased costs are the result of i) weak or missing security processes in the software supply chain, and ii) the increasing complexity of these supply chains.

These findings paint a worrying picture of software as a source of risk to organizations. The most effective way to mitigate this risk is to thoroughly test every application, particularly its source code, prior to release. Software teams can choose from many testing approaches to test, validate, and refine source code and build more secure software. One of the most effective approaches is Static Application Security Testing (SAST).

This article explains the role of SAST in the software development lifecycle (SDLC) and explores how it enables organizations to proactively address and mitigate security concerns in their software assets. It also highlights some best practices that empower dev teams to ensure effective SAST implementation.

What is Static Application Security Testing?

SAST is the analysis of an application’s source code to identify its security vulnerabilities before it is pushed to deployment. Since the code itself is reviewed during testing, SAST can uncover various issues related to coding errors and design flaws, as well as potential security vulnerabilities that increase the risk of breaches.

SAST is also known as white-box testing because SAST tools have access to the application source code, so they can analyze the application’s internal structure, logic, design, and implementation to discover flaws that may affect the application’s security.

After analyzing the code, SAST tools generate a report that contains details about the:

  • identified security vulnerabilities
  • locations and severity levels of each vulnerability
  • recommendations for remediation

All of this information helps developers to locate and fix the vulnerabilities before code deployment.

Benefits of SAST

One of the key benefits of SAST is that it doesn’t require execution of the application code and can therefore be performed early in the SDLC (during development). SAST enables development teams to identify and remediate vulnerabilities before they can manifest in production and create quality or usability issues for end users.

When vulnerabilities are discovered earlier, they can be remediated faster, which prevents development delays and ensures timely deployment and delivery. Also, since less rework is required to fix the issues, the development costs are lower. Early and comprehensive remediations also facilitate compliance with regulatory standards. This idea of early and frequent testing is known as “shift-left testing”, and is an important aspect of modern-day development approaches like Agile and DevSecOps.

SAST testing tools help to automate the security testing process, thus generating faster testing results and increasing testing coverage. Furthermore, they can automatically identify critical vulnerabilities, such as those listed in the OWASP Top 10 with high accuracy, allowing teams to consistently create more robust, secure-by-design applications.

OWASP Top 10 web application security risks Source

SAST tools can run at any frequency and at any time, making SAST suitable for continuous integrations and frequent builds. Also, after making remedial changes, developers can rerun scans to ensure that they didn’t miss any issues that could potentially compromise the application’s security.

The most useful SAST tools provide graphical representations of discovered issues, point out issue locations in code, and provide in-depth remediation guidance. These features enable developers to easily navigate the code, quickly fix problems, and keep the SDLC moving at a brisk pace. Additionally, built-in reports and dashboards make it easy to track issues and remediations, and thus ensure that critical problems are resolved before production and deployment. 

Limitations of SAST

SAST is a very effective way to identify many types of vulnerabilities in software code. However, it also has its limitations. For one, it cannot discover run-time and environment-related issues. Some tools cannot analyze configuration files, server settings, or other components. Others miss:

  • vulnerabilities that require runtime context to detect, such as authentication bypasses or session management issues
  • architectural or design-level vulnerabilities like overly permissive privileges or insecure data flows
  • vulnerabilities introduced through complex interactions between components
  • zero-day vulnerabilities
  • sophisticated or new attack vectors

Another major drawback of SAST tools is that they may generate false positives, often because they cannot accurately determine runtime behavior or the execution context for certain code paths. These “non-issues” can lead to wasted time, slow down the SDLC, and delay application deployment.

Best Practices for SAST Implementation

To run an effective SAST, one good practice is to select a tool that supports the application’s programming language. Not all tools can do this, so it’s important to check beforehand that the tool can perform code reviews in that specific language.

Another way to boost SAST effectiveness is to get the team used to working with the tool from the earliest stages of the SDLC because this can generate numerous benefits for the team and application (as already established).

It’s also important to set up the tool’s infrastructure (access controls, authorizations, etc.) before deployment to ensure that it works as expected and generates desired results. The tool should also be integrated into the build environment and customized, based on the team’s desired false positive thresholds and reporting requirements.

Finally, since SAST tools have their limitations, it’s best to use them together with Dynamic Application Security Testing (DAST) tools, manual security reviews, and penetration testing. This combined approach can help strengthen the application’s security to a much larger extent than would be possible with SAST alone.

How Backslash differentiates from traditional SCA/SAST

Backslash stands out from conventional Static Application Security Testing (SAST) tools by honing in on its exceptional capability to pinpoint vulnerabilities that are externally accessible. This specificity in identifying internet-reachable vulnerabilities allows Backslash to significantly reduce the common problem of alert noise found in traditional SAST applications. This noise reduction not only clarifies the landscape of potential threats but also highlights areas of potential internet exposure that require immediate attention.

Diving deeper, Backslash differentiates itself through a sophisticated analysis of source-to-sink flows within the application code, enriched by an understanding of the application's architectural context. This approach empowers Backslash to accurately prioritize vulnerabilities that are not just theoretically exploitable, but those that present a tangible risk based on their exploitability and reachability. Many SAST tools fall short in this area, bombarding users with a flood of alerts that lack a clear indication of severity or a defined path of attack, which can obscure critical vulnerabilities and impede effective threat assessment and remediation efforts.

In contrast, Backslash’s methodical focus on external reachability and the strategic prioritization of exploitable vulnerabilities paves the way for a more targeted and effective approach to security. By filtering out the noise and zeroing in on the most critical vulnerabilities with a clear understanding of the potential attack paths, Backslash enables organizations to not just respond to, but proactively manage and mitigate security risks with precision, elevating their overall security posture and compliance capabilities in the realm of SAST.


SAST is a critical component of modern software development practices. Numerous SAST tools are now available to find critical defects and integrate security considerations from the very beginning of the SDLC. By adopting these tools, organizations can more effectively address security concerns to protect their applications and substantially reduce the risk of data breaches.