Secure Coding for Developers

This roadmap helps developers write code that resists common attacks — input handling, authentication, access control, crypto, files, dependencies and secrets. You need experience in at least one programming language.

• Pick a language and framework you use daily
• Know the basics of how web applications work
• Plan your study time

• CyberA4U Academy — courses

Secure coding starts with a mindset: assume input is hostile, fail safely, and use proven libraries instead of inventing your own security.

• Think about how features can be misused
• Prefer secure defaults and proven libraries
• Use the OWASP Developer Guide

Tools & tech: Dev

• OWASP Developer Guide

Validate input for type, length, format and range as early as possible, preferably with allow-lists.

• Validate on the server side
• Use allow-lists and schemas
• Reject invalid input clearly

Tools & tech: Dev

Learn it on CyberA4U:Module 17: Database Query Injection Attacks

• OWASP Input Validation Cheat Sheet

Encoding output for its context (HTML, JavaScript, URL, SQL) prevents injection such as cross-site scripting.

• Use context-appropriate encoding
• Rely on framework auto-escaping
• Avoid unsafe raw HTML insertion

Tools & tech: Dev

• OWASP Cross Site Scripting Prevention Cheat Sheet

Common authentication mistakes include weak password storage, missing rate limiting, predictable reset tokens and insecure session handling.

• Store passwords with a strong hashing algorithm
• Rate-limit login and reset
• Manage sessions securely

Tools & tech: Dev

• OWASP Authentication Cheat Sheet

Broken access control is the top web vulnerability. Check authorization on every request, on the server, for every object.

• Enforce authorization server-side
• Check object ownership on every access
• Deny by default

Tools & tech: Dev

• OWASP Authorization Cheat Sheet

Use well-reviewed libraries and modern algorithms; never build your own crypto or hard-code keys.

• Choose appropriate algorithms and libraries
• Manage keys outside the code
• Use secure random numbers

Tools & tech: Dev

• OWASP Cryptographic Storage Cheat Sheet

File uploads and file paths are frequent sources of vulnerabilities: path traversal, malicious uploads and denial of service.

• Validate file type by content, not name
• Store uploads outside the web root
• Prevent path traversal

Tools & tech: Dev

• OWASP File Upload Cheat Sheet

Most code in an application comes from dependencies. Keep them minimal, updated and scanned.

• Scan dependencies for known vulnerabilities
• Update regularly
• Remove unused packages

Tools & tech: Dev

• OWASP Vulnerable Dependency Management Cheat Sheet

Secrets committed to code leak through repositories, logs and builds. Load them from the environment or a secret manager.

• Keep secrets out of source code
• Scan for committed secrets
• Rotate anything that leaked

Tools & tech: Dev

• OWASP Secrets Management Cheat Sheet

Tests can prove security requirements: unauthorized users are rejected, invalid input fails, sensitive data isn't returned.

• Write tests for authorization and validation
• Use ASVS requirements as test ideas
• Run them in CI

Tools & tech: Dev

• OWASP Application Security Verification Standard (ASVS)

A short security checklist in code review catches issues that automated tools miss.

• Build a security review checklist
• Apply it to every pull request
• Share findings as learning

Tools & tech: Dev

• OWASP Code Review Guide

Modern frameworks include CSRF protection, auto-escaping, parameterized queries and secure session handling — but only if you use them correctly.

• Know your framework's built-in security features
• Avoid disabling them
• Follow the framework's security guide

Tools & tech: Dev

• OWASP Cheat Sheet Series

Check that you can write and review code that avoids the most common vulnerability classes.

• Validate input and encode output
• Implement secure auth and access control
• Handle crypto, files, dependencies and secrets safely

• CyberA4U CTF Arena — practice challenges

You can now write more secure code. Continue with Application Security, DevSecOps Pipeline or Web Application Pentesting to see attacks from the other side.

• Keep your checklist
• Choose your next roadmap
• Share a before/after fix

• CyberA4U CTF Arena — practice challenges