Introduction to Interactive Application Security Testing (IAST)

What is IAST?

As modern applications grow more complex, security testing needs to keep pace with evolving threats. Interactive Application Security Testing (IAST) is a modern method for ensuring application security by analyzing how code behaves in real time as the application runs. By blending the best features of static application security testing (SAST) and dynamic application security testing (DAST), IAST provides robust coverage that identifies security flaws during execution. This proactive approach delivers continuous feedback to developers, which enables them to address vulnerabilities immediately as they interact with the application. Ultimately, this streamlines the development process and strengthens the security posture.

How IAST works

IAST operates by embedding security sensors directly into the application’s code, a process known as instrumentation. These sensors monitor the application’s behavior in real time, capturing interactions between the code and its environment. By combining elements of both static and dynamic testing, IAST can simultaneously analyze source code, runtime behavior, and HTTP traffic, offering a more holistic view of potential security issues.

This combination of static and dynamic analysis is called hybrid testing, which enables IAST to detect vulnerabilities in both the static code and during runtime. As a result, IAST can identify flaws that may only surface when the application is actively running. By working within the running application, IAST provides comprehensive coverage, uncovering risks that other methods may miss—such as configuration issues or runtime-specific threats. This empowers developers to quickly address vulnerabilities and fortify their application’s security posture.

Key benefits of IAST

Some IAST benefits include:

Real-time vulnerability detection

With IAST, security is woven into the fabric of the development process. By providing real-time feedback as the application runs, IAST enables teams to detect and remediate vulnerabilities early in the software development life cycle (SDLC). This proactive approach enhances security and helps avoid costly fixes later in the development process.

Accuracy and reduced false positives

One of the standout features of IAST is its ability to accurately observe application behavior, leading to precise detection of vulnerabilities. Unlike static or dynamic testing methods (SAST and DAST) that tend to generate a high number of false positives, IAST validates vulnerabilities in real-world conditions, dramatically reducing unnecessary alerts and allowing teams to focus on genuine security issues.

Developer-friendly integration

IAST tools are crafted with developers in mind, designed to integrate seamlessly into CI/CD pipelines. This means actionable insights are readily available during development, empowering teams to address vulnerabilities swiftly, without disrupting their established workflows. With IAST, security becomes a natural part of the development process rather than an afterthought.

Enhanced visibility for DevSecOps

IAST fosters a more collaborative approach to application security by empowering both security and development teams with detailed insights into vulnerabilities at runtime. This enhanced visibility enables teams to work together more effectively, ensuring that security risks are managed comprehensively and efficiently throughout the development lifecycle.

IAST compared to DAST and SAST

When it comes to application security testing, organizations often find themselves weighing the benefits of IAST against SAST and DAST. Each approach has its strengths, but IAST offers a unique combination of benefits that makes it a compelling choice.

SAST analyzes the application's source code and provides insights before the code is executed. While this method is fast and excels at identifying potential vulnerabilities early in the development process, it lacks the ability to detect issues that only arise during runtime, such as misconfigurations or complex interactions between components. It is also prone to false positives due to its lack of runtime context. As a result, teams may find themselves sifting through numerous alerts that do not translate into real security issues.

DAST, on the other hand, tests the application while it is running, mimicking an attacker's perspective. It effectively uncovers vulnerabilities present in the running environment. However, DAST lacks the code-level insights that can pinpoint the exact source of a vulnerability, making remediation more challenging. This outside-in approach often results in a limited understanding of how the application’s internal mechanics contribute to its security posture.

IAST bridges the gap between SAST and DAST by combining the strengths of both approaches. By embedding sensors in the application, IAST provides real-time monitoring of code execution and interaction with its environment. This allows for more accurate detection of vulnerabilities and significantly reduces false positives. Additionally, IAST integrates seamlessly into CI/CD pipelines, enabling developers to receive immediate feedback and remediate issues quickly.

IAST limitations

Some of the limitations to note for IAST tools include:

• IAST tools rely on the application being actively used or tested during runtime. If the code or functionality isn't exercised, vulnerabilities in untested areas may remain undetected. (blind spots)
• Instrumenting an application and running it with embedded security sensors can increase resource consumption, such as CPU and memory usage, during testing. This can slow down performance, especially for resource-constrained environments or applications with high runtime demands.

Enhance Application Security with Falcon ASPM

As the cybersecurity landscape becomes increasingly complex, adopting a proactive approach to application security is more critical than ever. By offering real-time vulnerability detection, improved accuracy, and seamless integration into development workflows, IAST provides  developers with critical insights they need to identify and remediate security risks. 

To complement application security testing, Falcon Application Security Posture Management (ASPM) ensures that organizations have complete visibility and insight into their deployed applications. Unlike IAST, Falcon ASPM does not require user activity or traffic to identify areas of risk within an application. Additionally, Falcon ASPM is completely agentless, meaning there is little to no impact on resources.

CrowdStrike Falcon® Cloud Security application security posture management (ASPM) gives teams a way to identify, assess, and prioritize their top application security risks based on what’s running in production right now.