# How a Static Code Analyzer Can Fix Application Security Issues
Security vulnerabilities are mostly a result of an application’s dependencies. In a bid to avoid “re-inventing the wheel”, we developers often go for ready-made libraries. These libraries’ creators ensure tight security around them, but there still can be errors at times.

There’s a very low chance that you discover these security issues during the execution of your code. This is because they do not break the syntax or code compilation, so if you aren’t careful, your application may have vulnerabilities without your knowledge. And by the time you discover it, you may have already been compromised.


[Image Source](https://www.zdnet.com/article/open-source-security-this-is-why-bugs-in-open-source-software-have-hit-a-record-high/)

Security is a big factor when building applications as any flaw may affect both the users and owners of the tool. This introduces the importance of security checks during development. There are many ways to go about checking security vulnerabilities, but for this scope of this article, we’ll talk about static code analyzers.

Static code analyzers have been gaining a lot of traction lately, and this is because they are the first step in discovering errors in source code. They have their benefits and limitations, all of which we’ll get to see in this article, and also how they play an important role in fixing application security issues.

## What is a Static Code Analyzer?

A static code analyzer is a tool that inspects non-executing code and throws warnings or errors at specific places that do not agree with the configuration made on the analyzer. They are also referred to as [SAST](https://www.perforce.com/blog/kw/what-is-sast) (static application security testing) tools.

Let’s break this down.

Without this analyzer, you’ll have to **execute** your source code to discover compiling or syntax errors. Static code implies code that is just written, not executed. With static code analyzers, you can discover errors in your IDE (or the analyzer-specific IDE) without even executing the codes.

Most static code analyzers also provide specific solutions for those errors and, in some cases, insights that can help developers resolve the errors. This technique makes debugging easier as you can fix nearly every error right in your IDE.

Static code analyzers are used a lot in application development. In some cases, they are referred to as linting tools. For example, [ESLint](https://eslint.org/) is used when building JavaScript applications.

## Getting Started with Static Code Analyzers for your Application

You can’t pick just any static code analyzer you find online. You need to make sure the tool can cater to your potential needs. Here’s a few to start with:

- Which programming language does the tool support?
- Is the tool’s community active?
- How many users does this tool have?
- Does the tool support [dynamic code analysis](https://en.wikipedia.org/wiki/Dynamic_program_analysis)?

Analyzers that support dynamic code analysis give you the benefits of analysis during program development (static code) and also during execution. Best of both worlds.

## The Benefits of Static Code Analyzers for Security

Some static code analyzers offer more than just discovering syntax errors from static code. They warn against bad indentations, the use of quotes, provide insights on coding standards, and many other things depending on the configuration. Some static code analyzers are specifically made for detecting security issues.

How do they do this by just looking at the code?

They scan through the application’s source code to determine poor coding patterns that malicious users can take advantage of. For example, a code implementation that changes a file name without authorization checks, or absence of input validations, not preventing access to inject contents into an application, and many more. When the analyzer comes across such patterns, it throws a warning which gives you insight on how to resolve them.

Some static analyzers also scan [dependencies](https://books.google.co.in/books?id=jVq9AQAAQBAJ&pg=PA116&dq=open+source+dependencies&hl=en&newbks=1&newbks_redir=1&sa=X&ved=2ahUKEwjpnLWA5azuAhWYlEsFHS8nCKEQ6AEwAXoECAcQAg) used in applications and compare them with some public databases that show vulnerable versions of several dependencies. Such analyzers give a warning on the dependency used and even a link for you to verify the reason they are classified as vulnerable.

## Limitations of Static Code Analyzers

While they are very beneficial, they have their limitations. Here are some of them:

- Support for programming languages is limited to only a few
- Can only identify what they “know” to be a security issue
- False-positive cases, where an issue identified is not an issue (this depends on how complex the tool is)
- Limited to static code, so security may be absent in static code but only present during the execution

## Conclusion

Static code analyzers play a very important role in application development. They help you identify errors faster even before you consider software testing. Using the right tool for your application increases application development efficiency while assuring secure code. In this article, we’ve looked at what static code analyzers are, their limitations, and their benefits in regards to building secured applications.