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Why are SAST solutions not the best option for AST?

The Basics of Static Application Security Testing (SAST)

First, let’s cover some basics of what exactly is SAST? It’s a set of technologies that analyze the application’s code, byte code, and binaries line by line. We call it white-box testing as the analyzed code is transparent and available. SAST offers:

  • Pinpoint accuracy when it comes to recognizing flaws in the code
  • Identification of vulnerabilities that you can’t detect without direct access to the source code
  • Identification of weaknesses that can become severe security risks later if they aren’t remediated immediately

SAST lets you pinpoint the exact location of a flaw. You see the precise line number in the source code that needs remediating. This reduces remediation time and effort for developers. SAST identifies many common vulnerabilities like XSS, buffer overflow, and SQL injection. It’s efficient when it’s implemented into the Software Development Life Cycle (SDLC) early. It lets us identify and remedy issues swiftly to save time and money if you use it correctly. SAST isn’t useless. It has a lot of strengths, but it also possesses many weaknesses.

Shortcomings of SAST solutions

We know now that SAST has pinpoint accuracy when it comes to finding flaws in the code. On the flip side, there are many issues that SAST can’t reliably identify. SAST falls short when it comes to finding issues connected to:

  • Authentication (how vulnerable is the code to brute force attacks, or is a password reset as effective as it can be, etc.)
  • Sensitive data storage and transmission (especially in cases when it can’t tell the difference between sensitive and non-sensitive data)
  • Privilege escalation and lack of authorization
  • Data privacy (making sure it masks certain sensitive information when it’s displayed)

The misuse of SAST is another issue. As mentioned above, SAST can’t reliably identify many things. Some organizations don’t have access to the source code. This is a big issue as SAST is very complex. For it to function properly it needs a semantic understanding of the code. This includes the codes’ dependencies, configuration files, etc. and lots of other pieces that are always in motion. Most aren’t even written in the same programming language. Can SAST understand all these moving pieces? While also being swift, accurate, and have a low false-positives rate? Not exactly. When a developer uses multiple code languages, multiple instances of SAST solutions need implementing.

That means all of them require separate maintenance and configuration. This adds a lot of overhead. The development also differs from the production phase. This entails problems in production that don’t exist in the non-compiled code. Another issue is Microservices. SAST can’t work in a world of Microservices. That’s a huge problem as most developers today use because they’re an architectural style that’s highly maintainable and organized around business capabilities.

The effectiveness of SAST goes down even further when JavaScript, Python, and other dynamically typed languages appear. 

Another issue is false positives. A developer can get a result that points out a lot of findings. Only it turns out most weren’t actually exploitable, or relevant. These results take time to examine and see if a flaw can seriously damage your application or not. SAST also doesn’t identify new kinds of vulnerabilities. You can customize it to perform this as well but it takes extra work from the development team. Developers can’t be 100% sure that their code is free of problems as SAST can’t detect a large number of them.

Should you choose DAST over SAST?

The best way to reinforce your security is to use both DAST and SAST. However, DAST has advantages over SAST. While SAST needs the language and the web application framework to work, DAST does not. DAST scanners are language-independent. They can scan HTTP, WebSockets, and API. Being a black-box solution it interacts with the app from the outside. Testing the app’s defenses against techniques that a hacker might use. DAST is able to identify both standard and severe security vulnerabilities. Some DAST solutions even detect 0-day vulnerabilities.

Because of its language independence, DAST is easily integrated into a CI/CD pipeline. It then scans the application, looking for ways to exploit vulnerabilities. DAST sends remediation guidelines as soon as it detects a vulnerability.

DAST is easier to use. It’s more effective at finding vulnerabilities that a hacker might exploit. Properly implemented DAST solutions even only report vulnerabilities that can be exploited to significantly reduce false positives. Most importantly, it saves a lot of money and time for both the developers and the SecOps team.

The superiority of NexDAST

One of the most cutting-edge DAST solutions on the market is NeuraLegion’s NexDAST. Why? Because:

– It integrates seamlessly into the CI/CD pipeline
– Developers get a ticket directly when a vulnerability gets identified
– 0-false positives (We validate that a vulnerability can be exploited  to avoid false-positive scenarios)
– Offers remediation guidelines for identified vulnerabilities.
– Flexible and accurate

NexDAST is easy to integrate into the most popular SDLC tools. This includes CircleCI, Github, Azure DevOps, Jenkins and others. NexDAST is also not destructive. Meaning it exploits vulnerabilities, but it does not create sustained damage. 

As examples:

SQLi (It registers the information about the data’s vulnerability without changing it)
XSS (Things that affect the user change, but no sustained damage is done)
OS Command Injection (It exfiltrates the exploit to confirm the vulnerability, but no files are deleted and the server doesn’t restart)

Want to find out more about NexDAST? We’ve covered it in-depth in one of our blogs before, and if you have a problem that NexDAST can help with, request a demo here!

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