If you are working in application security you certainly heard one or more of these terms, but what’s the real meaning behind the acronym? In this article, I will try to clarify this tongue twister list.

SAST: Static Application Security Testing

This family groups all the technologies dedicate to test the security of code at rest and will try to detect possible security issues, based on some strategies or policies.

This category can be further divided into three others:

• CSI – Code Static Inspection
  They scan the code, in source or binary format, looking for patterns that can lead to security issues, they can also enforce guidelines and policies. There’s a lot of choice of tools in this area, but I think you should always include Error Prone, praised by Doug Lea.
• SCA – Software Composition Analysis
  They scan the external component pulled along your code build looking for known vulnerabilities that can potentially expose the code to exploits later. It’s worth mentioning here that on average 80% of the code you ship it’s not your code but is somebody else’s code! Meterian, our host here, is, in fact, a SAST/SCA tool.
• SIS – Sensitive Information Scanners
  They scan the repositories where the code is stored in search of sensitive information inadvertently stored in them that can subsequently be leaked. It might sound a trivial thing to check, but it’s just good security hygiene to have one of such scanners in place. The effective to use greatly depend on your SDLC process, but I would strongly suggest using one of them, such as for example GitLeaks.

DAST: Dynamic Application Security Testing

This family groups tools used to test an application in an operating state (but not in production) using automated black box testing. They also frequently include specific security tests where the system tries to feed the application with malign data to simulate common patterns of attack. They interact with exposed interfaces such as APIs, network protocols, web pages. One opensource incarnation of such system is the Ebay DAST Proxy, released to the opensource community in late 2016.

RASP: Run-time Application Self-Protection

This is a very interesting category of tools where an agent is embedded into the application so that it protects the system at runtime and it’s typically deployed directly in production. The most common scenario sees the RASP agent “melted” with the application code through code instrumentation so that it can directly analyze the application behavior, providing active protection. A RASP, after detecting and blocking the attack, can shut down a user session, stop executing the application, and sometimes it also offers the ability to deploy code fixes at runtime. It also provides detailed reports that can be fed to monitoring systems. Baidu, the Chinese multinational technology company specializing in Internet-related services and product, is actively maintaining OpenRASP, an opensource RASP solution that works on Java and PHP web platforms.

IAST: Interactive Application Security Testing

These family of tools usually combine the RASP and DAST approaches: when testing an agent is embedded in the application while the test system executes attacks. This is a fully automated process so that it can be embedded in a continuous delivery system and ensure that a certain level of checking is done at frequently, even at every release, and with no human intervention.

Conclusions

What shall we do? As repeated endlessly again and again in the literature, you will need a complete approach to security testing, so considering using any of these tools is a step in the right direction. As we saw, there’re also opensource solutions available, so we do not really have any excuse to avoid putting this together.