IDOR learning path

Orientation and first principles — what the bug class is and how it behaves.

1. GraphQL IDOR Vulnerabilities: What They Are and How to Fix
   8 min readescape.tech2026
   Library focusing on preventing Insecure Direct Object References (IDOR) in GraphQL APIs. It details how IDOR vulnerabilities arise from improper validation of object identifiers, allowing unauthorized data access. The resource highlights real-world examples like vulnerabilities in PayPal, Vimeo, and Shopify, and provides practical advice on implementing strong authentication and strict authorization checks within GraphQL resolvers to mitigate these risks.
2. IDOR Attack Guide | Hackviser
   7 min readhackviser.com2026
   Guide detailing Insecure Direct Object Reference (IDOR) vulnerabilities, explaining how attackers exploit missing authorization checks in applications. It covers manual testing techniques including URL parameter, POST body, HTTP header, cookie, file access, and API endpoint manipulation. The guide also outlines automated discovery methods using Burp Suite and ffuf, and explores attack vectors like numeric and GUID/UUID manipulation, hash-based bypass, parameter pollution, mass assignment, and blind IDOR exploitation.
3. IDOR Vulnerability Exploitation Guide — RedfoxSec
   7 min readredfoxsec.com2026
   Guide to Insecure Direct Object Reference (IDOR) vulnerabilities, a critical OWASP Top 10 risk. This resource details how IDORs occur when applications trust user-provided object references without proper authorization checks, enabling unauthorized access to sensitive data. It covers common exploitation techniques like incrementing integer IDs, predictable GUIDs, and path traversal with examples using tools like Burp Suite Intruder and `curl`. The guide also discusses horizontal and vertical IDOR, provides a methodology for discovery, and highlights the importance of testing PUT, DELETE, and PATCH requests, along with harvesting object references from API responses.
4. What is IDOR? Complete Guide
   9 min readvaronis.com2026
   Guide to Insecure Direct Object References (IDOR), this document details how broken access control vulnerabilities allow attackers to manipulate direct object references like database keys or query parameters to access unauthorized data. It covers how IDORs work, including URL tampering, body manipulation, and cookie/JSON manipulation, and explains the risks such as data confidentiality breaches and integrity corruption. The guide also discusses detection methods using tools like Burp Suite and OWASP ZAP, and prevention techniques involving robust access control and session management.
5. How I found an IDOR in Google Classroom on Day 3 of my Hunting?
   3 min readinfosecwriteups.com2026
   Writeup detailing an Insecure Direct Object Reference (IDOR) vulnerability discovered in Google Classroom. The vulnerability stemmed from the `batchexecute` system, an undocumented internal RPC protocol. By manipulating `submission ID` parameters within POST requests to the `batchexecute` endpoint, an attacker could post private comments to any student's assignment submission, bypassing intended authorization controls and making the comment visible to the student and teacher. The writeup also explains how submission IDs were discoverable through traffic analysis.

Real testing methodology, tooling, and writeups that show the work.

1. How I Found a Cross-Student IDOR in Academy LMS That Leaked Correct Quiz Answers
   8 min readinfosecwriteups.com2026
   Writeup of a Cross-Student IDOR vulnerability in Academy LMS plugin, affecting over 2,000 installations. The vulnerability, discovered by analyzing the plugin's API controllers, allowed any enrolled student to view another student's quiz results and obtain correct answers. This was achieved by exploiting two authorization failures in the `get_student_quiz_attempt_details` endpoint, which incorrectly processed the `user_id` parameter from requests and evaluated access permissions against the target user's context rather than the caller's.
2. IDOR-Scanner: Burp Suite Extension for Automated IDOR Detection
   3 min readgithub.com2026
   Extension for Burp Suite that automatically detects Insecure Direct Object Reference (IDOR) vulnerabilities. It passively scans HTTP requests and responses for numeric fields in URL paths, query parameters, JSON, and form data. Actively, it increments these numeric fields, sending modified requests to identify confirmed IDORs by checking for differing response sizes and 200 OK statuses. An option to right-click and scan specific issues is also provided.
3. IDOR Vulnerability Detection Through HTTP Traffic Analysis
   20 min readsycope.com2026
   Analysis of Insecure Direct Object References (IDOR) attacks, which exploit missing server-side permission verification by allowing manipulation of resource identifiers in URLs, POST forms, REST API requests, cookies, and JSON objects. These attacks, ranging from horizontal (accessing data of users at the same privilege level) to vertical (gaining administrator access), are difficult for traditional firewalls and WAFs to detect as they appear as syntactically correct HTTP requests. Effective detection relies on analyzing HTTP traffic for anomalies like sequential enumeration, unusual error rates (401, 403), or atypical ID values, requiring a combination of preventive developer controls and detective security monitoring.
4. IDOR Hunting with Burp Suite: A $1,000 Bug Bounty Case Study
   7 min readherish.me2026
   Tool for hunting Insecure Direct Object Reference (IDOR) vulnerabilities, focusing on a $1,000 bug bounty case. It details how Burp Suite's Proxy, Repeater, and Intruder features can be used to identify and automate the discovery of IDORs by tampering with object identifiers and analyzing responses. The entry also covers common IDOR scenarios in APIs, including GraphQL and RESTful endpoints, and provides developer-side prevention techniques like server-side authorization checks and the use of indirect or signed references.
5. How to Find IDOR Vulnerabilities: The Bug Bounty Hunter's Practical Guide
   5 min readdev.to2026
   Guide to finding Insecure Direct Object References (IDOR) in bug bounty hunting, covering common IDOR patterns, including sequential integers, encoded IDs like base64, and MD5 hashes. It emphasizes the necessity of testing with two accounts, explores various IDOR types like read, write, delete, and function-level, and details methods for both manual and automated detection using tools like Burp Suite and ffuf. The guide also provides a framework for reporting IDOR vulnerabilities and suggests practice targets such as DVWA and PortSwigger Web Academy.

Novel research, edge cases, and the techniques that push the class forward.

1. Insecure Direct Object Reference (IDOR) - A Deep Dive
   5 min readhadrian.io2026
   Library covering Insecure Direct Object Reference (IDOR) vulnerabilities, detailing exploitation techniques such as ID parameter manipulation, direct request, mass assignment, token prediction, file path traversal, and API endpoint enumeration. It provides code examples for vulnerable and remediated scenarios, highlighting the impact of IDORs and mentioning CVE-2023-4836 in the User Private Files plugin for WordPress. Remediation strategies include implementing proper access control, using indirect references, employing GUIDs, and validating user input.
2. Predicting MongoDB ObjectId() continuously in Rocket.Chat
   12 min readaikido.dev2026
   Writeup detailing a vulnerability in Rocket.Chat, #3687142, where unauthenticated users can access any uploaded file by predicting its MongoDB ObjectId(). The article explains how the ObjectId() is composed of a timestamp, machine/process ID, and a counter, allowing attackers to enumerate valid file IDs and bypass authorization checks through the Livechat functionality.
3. New Types of Hacking: IDOR Attacks Evolved
   theosintedge.medium.com2026
   New Types of Hacking: IDOR Attacks Evolved
4. Broken Access Control: Advanced IDOR Exploitation
   6 min readweekly-bugbounty-content.beehiiv.com2026
   Library for advanced exploitation of broken access control vulnerabilities, focusing on Insecure Direct Object References (IDORs). It covers "object-based" IDORs with JSON manipulation, multi-step IDORs hidden behind workflow sequences, second-order IDORs where input indirectly references resources, and "ID-less" IDORs that bypass direct ID references. Techniques explored include wrapping IDs in arrays, object mapping, boolean usage, and various ID manipulation attempts.
5. Chaining password reset link poisoning IDOR and information leakage to achieve account takeover at api.redacted.com
   medium.com2021
   A security researcher successfully exploited a vulnerability at api.redacted.com, achieving account takeover. The attack involved chaining together three distinct vulnerabilities: password reset link poisoning, an Insecure Direct Object Reference (IDOR), and information leakage. This combination allowed the attacker to gain unauthorized access to user accounts.