Broken Access Control

Summary

Failures in enforcing what an authenticated user is actually allowed to do — accessing another user's data by changing an ID in a URL is a classic, extremely common example.

• 1Test a practice app for an Insecure Direct Object Reference (IDOR) by manipulating a resource ID.
• 2Learn why this is consistently the most reported OWASP category in real-world audits.
• 3Understand the fix: server-side authorization checks on every request, never trusting client-side hiding alone.