IDOR testing rewards a systematic approach. Rather than poking at individual parameters, work through the application methodically.
1. Identify references
Walk every workflow and record where the application exposes an object reference: sequential IDs, UUIDs, filenames, and encoded tokens. Include references hidden in redirects and export links.
2. Classify each reference
For each reference, note whether it is read or write, what object it addresses, and what authorization the application should require. This turns a list of parameters into a list of testable hypotheses.
3. Prove cross-user access
Using two accounts, attempt to access each object as the wrong user. Record the exact request, the response, and the sensitivity of any data returned. A reproducible proof of concept is the deliverable.
4. Assess scope
Where a reference is enumerable, estimate how many objects are affected without exfiltrating real user data. Scope drives severity.
Sample content for development and testing. Test only with authorization.