Interactive Application Security Testing (IAST) tools combine elements of both static and dynamic testing to identify vulnerabilities within applications and APIs during execution, in real time.
The IAST market was valued at USD $1.2 billion in 2024 and is estimated to grow at a CAGR of 12.5% between 2026 and 2033 to reach a total value of USD $3.2 billion.
The overall application security market has an estimated value of $13.64 billion USD.
Static Application Security Testing (SAST) tools currently hold the largest revenue share within the wider security testing market, and Dynamic Application Security Testing (DAST) tools are expected to grow with the highest CAGR.
IAST is an emerging sector within cybersecurity. However, as IAST combines features from the above approaches to deliver the “best of both worlds”, we expect to see significant growth in this market.
Growth is largely being driven by evolving compliance regulations, and the increasing adoption of DevSecOps practices, which calls for developers to integrate security measures earlier on in the software development lifecycle.
IAST tools enable dev teams to meet these requirement without slowing down their development cycles, thanks to their automated testing and real-time alerting capabilities.
Why trust us: We’ve researched, demoed, and tested several leading IAST solutions, spoken to organizations of all sizes about the challenges they’re facing and the features that are most useful to them, as well as interviewed executives from leading providers in the IAST and wider application security testing spaces.
You can find our product analysis reports, interviews, and Top 10 shortlists of the best IAST products on the market in our DevSecOps Hub.
Know Before You Buy: Our Recommendations
Before we jump into the details, here are our top tips on how to get the most out of your IAST implementation:
For streamlined development: Integrate your IAST tool with your CI/CD pipeline so that you can gain feedback continuously throughout the development cycle. This will allow you to fix issues as they’re identified rather than having to go through them all at the end, saving you time and money.
For getting the most out of the tool: IAST isn’t a viable approach for apps that are still early in their development cycle or don’t yet have a stable build. To get the most out of your IAST tool, run your tests during the later quality assurance (QA) stages of development.
For best security practice: Fix any high/critical severity and exploitable vulnerabilities identified by your IAST tool before your application reaches production. This will help keep your app’s users secure, and it’ll be easier to carry out those fixes in development than in production.
How IAST Works
IAST tools are often referred to as “gray box testing”; they take an approach that sits somewhere in between “black box” and “white box”:
- In black box testing, tests are run based solely on the program’s behavior; testers have no access to the application’s underlying source code.
- In white box testing, testers have full access to the application’s source code.
IAST tools scan applications and APIs while they’re being executed by a human tester or an automated test runner. As the tester interacts with each feature, the IAST tool gives the developers real-time feedback on how they respond under certain conditions.
To do this, IAST tools use sensor modules to test the code behind each feature. These sensors access the code itself, as well as data flows, control flows, system configuration data, back-end connection data, and web components. If the IAST tool identifies a vulnerability, it reports back to the development team with details on the vulnerability and suggestions on how to address it, including information on where in the source code the vulnerability is located, to enable developers to find and remediate the issue quickly and precisely.
In terms of deployment, IAST solutions are designed to run tests on web-based applications. Most IAST tools scan code that’s being used in production, but the best solutions offer integrated development environment (IDE) integration to allow developers to test their code during development.
Deploying An IAST Tool: Key Considerations
During deployment, you can choose to use invasive or non-invasive sensors:
- Invasive sensors (used by most IAST tools) require you to instrument your source code. This means you have to maintain two separate versions of your code—one with sensors, and one without.
- Non-invasive sensors attach to the server-side runtime environment and analyze the code as it’s executed by the web or app server. This means you don’t have to modify the source code for them to work.
Finally, IAST tools can be deployed independently (“passive” or “self-sufficient” IAST) or alongside a DAST tool (“active” or “DAST-induced” IAST):
- With an active IAST implementation, the DAST tool activates the IAST sensors and uses them to validate vulnerabilities found during DAST attack simulations. Active IAST provides accurate results, but it requires you to build a testing environment and it can’t be automated, making it unsuitable for large-scale or fast-paced development environments.
- With a passive or standalone IAST implementation, you don’t need to run dedicated tests or simulated attacks; instead, the IAST tool automatically collects vulnerability data during all forms of functional testing. This makes passive IAST well-suited to fast-paced environments.
Benefits Of IAST
There are three main benefits to implementing an IAST solution:
1. IAST tools are designed to work in tandem with most popular tools and environments that your dev team is already using.
Because they analyze vulnerabilities in real-time, IAST tools integrate easily with CI/CD pipelines.
The best IAST tools also integrate with IDEs. This enables you to discover and fix vulnerabilities during development, before your app goes to market—which is easier and cheaper for you, and allows you to provide your customers with a secure, reliable product.
2. Due to the enhanced visibility it provides, IAST tends to have a lower false positive rate than other types of application testing, which helps reduce alert fatigue.
IAST tools provide insight into actual data flow, code execution paths, app configuration, and runtime behavior. This gives them the contextual awareness to confirm whether a vulnerability is actually exploitable, reducing false positives.
Plus, by testing the app’s source code while it’s running, IAST tools enable you to scan code being used in production, helping you avoid false positives that may have already been addressed in other parts of the code base.
“The number one thing you need to do is make sure you’re not getting noise,” Frank Catucci, CTO at Invicti tells Expert Insights. “It only takes a second to burn a bridge with a developer when you give them a false positive… First and foremost is making sure that accuracy is there.”
3. IAST offers some of the key benefits of DAST and SAST, without you having to sacrifice any visibility.
SAST tools trace vulnerabilities back to the source code, but don’t provide visibility into runtime performance. This is a “white box” testing approach.
DAST tools identify issues based on the application’s behavior, but don’t provide visibility into the underlying source code. This is a “black box” testing approach.
IAST tools take a “grey box” approach, searching for vulnerabilities within the source code based on runtime behavior.
Common IAST Challenges
There are two main challenges that you might come across when implementing an IAST solution. Here’s what they are and how to overcome them:
- The sensor modules within an IAST tool may only be compatible with certain languages and environments. Before investing in a tool, make sure it’s compatible with your project—particularly if you’re using any less popular or mainstream technologies.
- IAST tools can only be used while your code is actively running. This means the code has to be fully compiled before the IAST tool can work, so it may not be the fastest way to run certain tests. It can also mean that you miss certain interactions on edge cases. To avoid that, make sure your testers know exactly what functionality they need to test, or deploy the tool in a QA environment that runs automated, functional tests.
Best IAST Providers
Our team of software analysts and researchers have put together a shortlist of the best providers of patch management solutions, as well as adjacent lists covering similar topics:
- Top Interactive Application Security Testing (IAST) Tools
- Top Application Security Testing Solutions
- Top DevSecOps Tools for Application Security
Features Checklist
When comparing IAST solutions, Expert Insights recommends looking for the following features:
- Straightforward deployment: The solution should be straightforward to deploy, with little-to-no need for custom configuration.
- Integrations: The solution should integrate seamlessly with your CI/CD pipeline, including any build, test, QA, and bug tracking tools you’re already using. It should also offer web-based APIs that allow you to integrate it with any other tools that it doesn’t support out-of-the-box.
- Automated vulnerability testing: The solution should automatically scan your application for vulnerabilities. Make sure it’s able to identify OWASP Top 10 vulnerabilities and, to save time, offers options to scan only new code or code that’s been edited since the last scan.
- API and microservices testing support: The solution should be compatible with whatever architecture your project is built upon, e.g., cloud-based, standard, or microservices-based. If your app uses microservices, look for a tool that will test the security of its APIs.
- Compatibility with testing methods: The solution should support any testing methods you’re planning on using, such as automated test runners, manual QA/dev tests, unit testing, web crawlers.
- Real-time alerting: The solution should alert your team to any detected issues in real time, so you can fix them as quickly as possible.
- Low false positive rate: You should be able to set up your solution to only scan code that’s actually being used in production, so that it doesn’t flag any issues that have already been solved elsewhere.
- Guided remediation: The solutions should provide remediation guidance to help you address any issues it detects. This should include telling you the exact location of any vulnerabilities, so they’re easier for you to find and remediate.
- Compliance support: The solution should keep tabs on sensitive data to ensure your code remains compliant with standards such as GDPR.
Further Reading
You can find all our articles on IAST software in our DevSecOps Hub.
Want to jump right in? Here are a few articles we think you’ll enjoy:
- Shortlist: Top Interactive Application Security Testing (IAST) Tools
- Article: Application Security Testing: A Deep Dive Into Automating AST For Maximum Protection
- Interview: Invicti’s CTO On Finding The Right AppSec Solution
Interview:Avi Shua On The Power Of Unified, Cloud-Native Security
