Writing Secure Python Applications: Preventing SSRF, SQL Injection, and XSS
1. Core Security Foundations Treat all input as untrusted. Validate strictly (whitelists over blacklists), normalize before checks, and enforce types and sizes. Use framework security features instead of writing your own. Least privilege: minimize DB, filesystem, and network permissions. Secrets management: use environment variables or secret stores, never hardcode. Dependency hygiene: pin and audit dependencies with pip-audit or Safety. Secure HTTP headers: add HSTS, X-Frame-Options, CSP, and others. Logging & monitoring: log relevant events, but never credentials. Testing: integrate Bandit and Semgrep in CI. 2. Preventing SQL Injection (SQLi) Principle: Never build queries using string concatenation. ...