Writing clean, extensible, and scalable code is very important for developers. However, since data is a significant part of today’s software applications, secure code is also a major consideration. For larger applications with several thousands of lines of code per file, it is a big challenge to ensure security vulnerabilities are caught. Add to this the constantly updated third-party and open source libraries imported into a project’s codebase, and you’ll quickly find yourself in a security rabbit hole.
What is SAST?
Code reviews can definitely help. But human reviewers can only do so much. This is where Static Application Security Testing (SAST) can help. SAST is a method of testing applications at the source code, byte, and binary levels. The objective of SAST is to search for code defects, including security vulnerabilities. SAST does this without having to execute the code in question.
SAST is also popularly known as “white-box testing” as it does its job by fully accessing the application’s internals. In contrast, DAST or Dynamic Application Security Testing is called “black box” testing as it only tests an application in its running state without considering the underlying codebase.
Why is SAST Important?
As mentioned previously, it is imperative that security vulnerabilities be detected – the earlier in the software development lifecycle, the better. The first place to begin is referring to the OWASP Top 10 to determine which vulnerabilities are imperative to be protected against. As attackers get better and better at exploiting vulnerabilities, responsible developers cannot stay put. Each additional code written or each new update to open source libraries being used requires maximum test coverage.
Most organizations employing CI/CD have to incorporate automated testing to ensure defects and vulnerabilities don’t reach users. This doesn’t mean the burden for ensuring vulnerability-free application solely falls on the DevOps team. Coders must ensure they catch vulnerabilities early on. SAST not only ensures detecting such vulnerabilities but also should be able to recommend remediations.
Performing SAST Effectively
First of all, the right tool should be selected. The tool to choose depends on many factors, including which programming language or framework is used. The following section lists some great tools.
Another critical step is setting up the right environment to perform SAST. Smaller applications and teams may perform SAST in the development environment alone. Larger scale apps and teams should have QA and pre-production environments as minor changes during the build can introduce issues. It is important then to ensure each deployment is being tested, including SAST.
Next, as the number of lines of code increases, it becomes inefficient to analyze everything at once. It is crucial then to prioritize lines of code that have the highest security risk. For instance, user forms that can be exploited for SQL injection attacks can be scanned first.
Lastly, scan results should be well analyzed to identify the remediation to be employed. In some cases, there will be false positives – or flagged code that aren’t really vulnerabilities. Proper analysis of scan results ensures the team will invest the right resources to fix vulnerabilities.
Top 3 Tools for SAST
Klocwork is a great SAST tool for C, C++, C#, and Java developers and works best with enterprise-level large-scale DevOps and DevSecOps environments. The Differential Analysis engine integrates well with the organization’s CI/CD pipeline and delivers instant, accurate results. This ensures each commit is free from vulnerabilities.
Klocwork not only finds vulnerabilities in real-time as they’re introduced in the code base, but it also fixes them right away. The results are benchmarked against industry and organization standards. This ensures compliance.
Some of Klocwork’s key features are:
- DevOps-ready: SAST is smoothly integrated into the CI/CD pipeline providing a solid layer of protection against vulnerabilities.
- It promotes collaboration: Klocwork Portal is a central source of data, configurations, and other information that cross-functional teams can access through the web.
- Developer-friendly: Klocwork needs no configurations. It has a vast array of plugins for most IDEs.
Veracode’s SAST tool has three methods that help security testing within the Software Development Lifecycle: IDE Scan, Pipeline Scan, and Policy Scan.
IDE Scan allows developers to discover vulnerabilities in real-time while coding. It scans the code while it is being written and shows feedback for the devs to ascertain whether they’ve written secure code or not before pushing code to production. Developers also get the chance to learn faster as they’re given positive reinforcement and access to tutorials that inform them better.
Pipeline Scan is geared more for DevOps engineers. It integrates well into the CI/CD pipeline so the DevOps team can quickly determine any problematic code not caught by devs and promptly give feedback to the devs.
Policy Scans ensure the apps being built comply with policies and security standards. The application is scanned and compared to policies and standards, and a summary report is given that will show the team how well the app abides by these.
SonarQube is an open-source tool from SonarSource which performs continuous code quality inspection. It provides support for over 25 programming languages and can be extended using plugins.
While it ensures the catching and remediating of security vulnerabilities, it also detects and fixes code smells such as unused variables, duplicated code, and other bugs. This means developers can minimize or completely eliminate technical debt as new issues are traced in real-time.
Setting up SonarQube is easy and quick. A major requirement is having Java installed. Then the tool can be downloaded and can be run out of the box. It has several different scanners depending on the project and environment wherein the code base is being scanned.