---
title: TLS Clients Must Validate Server Certificates
impact: CRITICAL
impactDescription: prevents man-in-the-middle attacks
tags: tls, certificates, validation, mitm, security
---

## TLS Clients Must Validate Server Certificates

This rule ensures high quality and security in Python and PySpark applications.

**Implementation Guidance:**
- Follow standard Python best practices (PEP 8)
- Use type hints for better clarity
- For PySpark, prefer DataFrame API over SQL strings where possible
- Ensure proper resource management (using \`with\` statements)