Automating Security in Python: A Hands-On Guide to SAST with Bandit and GitHub Actions

Introduction

In today's fast-paced development cycles, security can no longer be an afterthought. Static Application Security Testing (SAST) tools help developers catch vulnerabilities early by analyzing source code before it is compiled or deployed to production.

In this article, we will explore how to apply a SAST tool to a Python application. While tools like SonarQube or Snyk are popular, we will focus on Bandit, a powerful and lightweight tool designed specifically to find common security issues in Python code.

What is Bandit?

Bandit is an open-source SAST tool maintained by the Python Packaging Authority (PyPA). It parses Python code, builds an Abstract Syntax Tree (AST), and runs appropriate plugins against the AST nodes to detect security flaws like hardcoded passwords, injection vulnerabilities, and unsafe library usage.