Exploit IDOR Goal Determine whether object identifiers can be manipulated to access another user's data or actions. Assumptions the app exposes object-specific routes, IDs, or references authorization might be weaker than authentication the server may trust client-supplied identifiers too much Prerequisites authenticated test accounts with different privilege scopes ability to capture and replay requests understanding of object locations in the app Recon steps Map endpoints that expose object IDs in paths, query params, forms, or JSON. Compare requests from two different users. Look for predictable IDs, UUID reuse, sequential records, or leaked references. Exploit / test steps Capture a request that accesses one object. Change only the object identifier. Replay the request with the same auth context. Try both read and write operations. Repeat across hidden endpoints, exports, downloads, and mobile/API routes. Validation clues another user's object is returned writes succeed against another user's resource response metadata changes without an authorization error timing or status changes indicate object existence Mitigation enforce authorization on every object access server-side use indirect references only as a helper, not a replacement avoid relying on UI visibility for protection log authorization failures and suspicious object access patterns Logging / detection repeated access attempts across adjacent IDs many 403/404 combinations across the same route family auth context accessing objects outside expected ownership scope Related notes broken-access-control Broken Object Level Authorization http-messages References Testing / Lab: PortSwigger IDOR page — https://portswigger.net/web-security/access-control/idor Testing / Lab: PortSwigger access control topic — https://portswigger.net/web-security/access-control Foundational: OWASP WSTG authorization testing — https://owasp.org/www-project-web-security-testing-guide/latest/ ← PreviousDetect Kerberoasting and AS-REP RoastingNext →Exploit SQL Injection Explore nearby notes Security PlaybooksBreak JWT ValidationIdentify whether JWT handling is weak enough to allow acceptance of invalid, stale, mis-scoped, or attacker-influenced tokens. Security PlaybooksDetect DCSync and ntds.dit AccessDetect both forms of bulk Active Directory credential extraction — **DCSync** (IDL_DRSGetNCChanges via the DRSUAPI RPC interface) and **offline ntds.dit... Security PlaybooksDetect External Recon Scan PipelineDetect an external operator running a two-phase Masscan → Nmap-NSE recon pipeline (the offense playbook run-scan-pipeline) against your perimeter, with high enough... Security PlaybooksDetect Kerberoasting and AS-REP RoastingDetect both Active Directory Kerberos credential-attack families (Kerberoasting and AS-REP Roasting) via behavioral analysis on Event IDs 4768/4769 and... Security PlaybooksExploit SQL InjectionDetermine whether user-controlled input can alter SQL query logic in a way that changes access, data, or behavior. Security PlaybooksInspect File Upload SurfaceDetermine whether upload features create unsafe execution, storage, parser, or exposure paths.