TOP 10 / OWASP 2025 — Introduction 00 / 14
OWASP Top 10 · 2025
Introduction to
OWASP Top 10
Ten vulnerability patterns that reach production systems every day. See if you can recognise them.
OWASP Top 10 · 2025 Edition

Ten ways production systems actually get compromised.

You're about to see ten incidents — a support ticket, a Slack alert, a postmortem finding. Each one is a different vulnerability pattern from the OWASP Top 10. Your job is simple: read the signal and pick what kind of problem it is.

Some you'll recognise immediately. Others might surprise you. Both reactions are useful — that's the point.

~8 minutes · no code in this module
You'll classify each incident, get immediate feedback, and see which OWASP category it maps to. The deep dives — code review, exploits, fixes — live in the individual modules after this.

// recognition score

0 / 10
calculating...

// the ten modules ahead

Each vulnerability gets its own module.

You'll go deep — real case, code review, exploit walkthrough, multi-language fix, knowledge check. Start with whichever felt least familiar.

// carry this forward

the pattern behind all ten

Every vulnerability on this list exists because code trusted something it shouldn't have — an input, a default, a dependency, an assumption about what would never happen.

This module
Recognition — you saw the signals
You've now seen every OWASP Top 10 category as an incident, not a definition. The names should feel like something you've encountered, not something you memorised.
Next
Each module — code review, exploit, fix, self-check
Every module follows the same arc: a real case anchors the vulnerability. You find the vulnerable line. You watch the exploit. You see the fix in multiple languages. You test yourself. Start with whichever pattern felt least familiar.
Right now
One thing to check in your codebase today
Pick the incident that felt most familiar. Open your codebase. Search for the pattern — not whether it exists, just where you'd start looking. That single search is worth more than finishing this module.