SAST discovers potential issues in source code by analyzing code without actually executing it. It's an objective way to save developers' time by finding security defects in code earlier in the development process, an approach known as Shift-left. The principle of Shift-left is to take a task that's traditionally done at a later stage of the software development process and perform that task at earlier stages. The earlier you identify security flaws in your code, the more cost-effective it is to address them. But shifting left requires an adjustment in your development team's culture where the engineer who writes the code is responsible for fixing the security issues introduced in source code.

Let's look into how SAST can improve code security through a Shift-left approach:

Developers own source code security

The practice of Shift-left encourages software engineers instead of security teams to be responsible for producing secure, reliable code. It's one thing to have a shift-left mindset, but as part of an actual Shift-left process, Static Application Security Testing (SAST) materially shifts the responsibility of source code security assurance onto development teams and away from a dedicated security team.

Early detection of security issues

Incorporating SAST early in the code-review process is a proactive apporoach to detecting security issues in source code. Not only does SAST improve overall security posture, but the earlier it's applied, the less expensive it is to solve issues. Developers can go through a security checklist before pushing code to production rather than waiting for a security team to scan for vulnerabilities afterward.

Security risks increase when source code is already released

The worst time to discover a security flaw is after your software is in the wild, where malicious actors have unfettered access and can exploit vulnerabilities freely. While SAST identifies potential bugs and security vulnerabilities, it can also reveal code that's non-compliant with coding standards. By running SAST as part of code review process, your development team can catch and address potential problems before they grow into major security failures and breches down the line. Shift-left places your security reviews far in advance before any public exposure.

Continuous analysis helps mitigate problems

Running SAST continuously guarantees that your code security is kept consistent and up-to-date throughout the development process. Instead of running SAST in periodic intervals, it is run everytime a source code change is made (for example, in GitHub pull requests). The outcome of Shift-left for security review is a higher level of protection against security vulnerabilities at a fraction of the cost of more traditional methods: in other words: efficiency.

How SAST improves your codebase's security

SAST allows developers to review the Open Web Application Security Project (OWASP) Top 10, a list of the most common attacks on web applications. By detecting OWASP vulnerabilities in source code, developers can address these vulnerabilities consistently, ensuring that audits for SOC2, ISO 27001 go more smoothly.

Leveraging SAST to Review the OWASP Top 10

OWASP Top 10 is a classification of the most common attacks on web applications. It is compiled by Open Web Application Security Project, a non-profit organization striving to improve web application security. SAST can detect OWASP Top 10 vulnerabilities in source code, which allows you to address these vulnerabilities consistently.

Here's the updated list with associated risks:

• Broken Access Control: If access control systems aren't implemented correctly, a user can gain privileged access to your system, misuse an API, or act as a different user.
• Cryptographic Failures: User data must be encrypted in transit and at rest and shouldn't be encrypted using weak or old cryptographic algorithms or protocols.
• Injection: Code injection is an attacker sending invalid data into a web application, attempting to get the application to do something it's not supposed to.
• Insecure Design: Insecure design is a broad category representing different weaknesses, expressed as “missing or ineffective control design.
• Security Misconfiguration: Missing appropriate security hardening across any part of the application stack or improperly configured permissions on cloud services.
• Vulnerable and Outdated Components: Applications with vulnerable, outdated or unsupported components or third-party packages.
• Identification and Authentication Failures: A typical A07 vulnerability results from allowing weak passwords, permitting brute-force attacks, inefficient password recovery workflow, incorrect invalidation of session IDs, etc.
• Software and Data Integrity Failures: If your application relies on third-party packages from untrusted sources, it's vulnerable to unauthorized access or system compromise by injecting malicious code aka "supply-chain attacks."
• Security Logging and Monitoring Failures: The lack of logs for critical workflows or an alerting mechanism in case of anomalies can make your system vulnerable to clandestine attacks.
• Server-Side Request Forgery (SSRF): Fetching a remote resource without validating the user-supplied URL can allow an attacker to coerce the application to send a crafted request to an unexpected destination.

Addressing the OWASP top 10 also helps instill a culture of code security in software development teams. By understanding the importance of security in the development process, software engineers will become better at writing more secure code.

SAST prevents hardcoded secrets from being exposed

Developers often hardcode secrets to get code functioning quickly. Whether it's an API key, a password, or other sensitive data, hardcoding secrets into code is generally considered bad practice, and can lead to problems if the code is later exposed. Malicious entities can exploit hardcoded credentials to gain access to your systems. SAST can help prevent this from happening by automatically scanning code for hardcoded secrets by looking for specific patterns of code that are at risk of exposing sensitive information.

SAST finds Infrastructure as Code security (IaC) issues

Infrastructure as Code (IaC) is the process of managing and provisioning infrastructure using code rather than manually configuring it. IaC workflows are becoming increasingly popular as they offer greater flexibility and control over the infrastructure. But these workflows can be complex and challenging to keep it secure. SAST can help make IaC workflows more secure by identifying potential security issues early on. You can fix these issues before they cause damage. SAST can also help create more secure IaC templates and configs that can be reused across different projects, making your IaC security review scalable.

Steps to incorporate SAST into your development workflow

Find a SAST Tool

The first step is to find a SAST tool that meets your requirements. Some things you'll want to consider when thinking about purchasing a SAST tool:

• Reporting: Quality of the reported errors is the litmus. Quantity can be due to false positives/negatives.
• False positives/negatives: A high number of false positives is bad because it adds noise to the results and slows down the remediation process due to inaction.
• Onboarding: Ease of onboarding is key if you have hundreds or thousands of repositories.
• Programming language support: Does it cover the languages you use in depth?
• Speed: Evaluate analysis time and performance based on the size of the codebase.
• Security coverage: Detection of issues in OWASP Top 10 and CWE Top 25.
• Support/Documentation: Response time and competence. Check review sites like G2 to get more information.

Integrate with the source code hosting provider

Integrate SAST into your code-hosting providers, such as GitHub, GitLab, Bitbucket, Azure DevOps, etc. by granting the tool relevant permissions to access your repositories. Depending on the provider, this can be done through their own authentication system or by granting a personal access token. Once connected, the SAST tool will automatically scan your code for potential issues, bugs, and discrepancies and alert you if any are found. It will also track over time to help you quickly identify trends or areas of your code that require improvement or refactoring. This streamlined integration helps developers focus on delivering quality code quickly, securely, and efficiently.

Create awareness amongst engineers

Create awareness amongst engineers on the chosen SAST tool, as they'll have to use it every day. Learning how to use the SAST tools effectively gives your engineers ownership over the code security review process. Educating your engineers on the basics of software security and how to properly use a SAST tool will instill confidence in their work, enabling them to identify and fix security issues quickly and efficiently. Additionally, training your engineers on how to use the tool and how to fix potential security issues found will help you make sure that it is being used properly and that no vulnerabilities are created as a result of its use.

Gradually onboard repositories

Onboard repositories for scanning to the tool, gradually. You don't want to overload your engineering team with too much work at once. You can add more projects as your engineers get more comfortable using the tool.

Set up continuous SAST

The last step is to set up continuous SAST for any projects you've added, so you can automatically check your code for errors and potential issues on every source code change. Setting up continuous integration allows your SAST tools to run against any new code every time a change is made to your code base (ideally as part of the pull request workflow). Continuous SAST means that code changes don't affect your security mid-stream in the development process. This is an essential part of shifting your security review to the left.

SAST improves your security posture when implemented in a "Shift-left" manner for objective code review. It helps establish a security-first culture in your software development team. By automating objective code reviews, SAST catches code flaws that would otherwise go undetected and allows developers to improve overall code quality. The result is a lighter-weight, less expensive, more efficient, and more robust process that puts the responsibility for security onto the people writing the code.

Check out DeepSource to setup SAST and improve your code security.