4. IDOR & Access Control

4. IDOR & Access Control: IDOR is like walking down a street of Lego houses and changing the house ID (from userId=5 to userId=6) in the URL to open your neighbor's front door an

IDOR is like walking down a street of Lego houses and changing the house ID (from userId=5 to userId=6) in the URL to open your neighbor's front door and access their private toy box.

2 Analogies: IDOR Vulnerabilities

2 Reasonings: Why IDOR Occurs

Only Checking Authenticated Status

Predictable Database Identifiers

2 LEGO Analogies: Access Verification Bricks

Vulnerability Simulation

Which of the following URLs is most susceptible to an IDOR exploit?

https://shop.com/api/getInvoice?id=1025

https://shop.com/api/getInvoice?id=d29038d1-12f3

https://shop.com/api/my-profile

https://shop.com/api/searchProducts?query=shoes

An integer ID like id=1025 is sequential and easily guessable. Changing it to 1026 allows attackers to scan and retrieve other client invoices.

What is the most robust way to mitigate IDOR vulnerabilities?