1. What does IDOR stand for in cybersecurity?
A) Internal Data Object Redirection
B) Insecure Direct Object Reference
C) Indirect Data Object Retrieval
D) Internal Database Object Reassignment
Answer: B) Insecure Direct Object Reference
Explanation: IDOR is a security vulnerability that occurs when an application exposes direct access to objects based on user input, without proper authorization checks.
2. Which of the following is an example of an IDOR vulnerability?
A) A user accessing another user’s account by modifying the user ID in the URL
B) A SQL Injection attack allowing database access
C) An attacker using a phishing email to steal credentials
D) A buffer overflow attack crashing an application
Answer: A) A user accessing another user’s account by modifying the user ID in the URL
Explanation: IDOR occurs when an application exposes object references (like user IDs) without proper access controls, allowing unauthorized access to sensitive data.
3. What is the primary cause of IDOR vulnerabilities?
A) Weak password policies
B) Lack of proper authentication
C) Improper authorization and access control
D) Using outdated cryptographic algorithms
Answer: C) Improper authorization and access control
Explanation: IDOR vulnerabilities arise when applications fail to implement proper authorization mechanisms to verify if a user has permission to access an object.
4. Which of the following security measures helps prevent IDOR vulnerabilities?
A) Implementing rate limiting on requests
B) Using CAPTCHA to prevent bots
C) Enforcing role-based access control (RBAC)
D) Encrypting all GET and POST requests
Answer: C) Enforcing role-based access control (RBAC)
Explanation: Proper authorization checks, such as RBAC, ensure that users can only access resources they are authorized to view or modify.
5. How do attackers typically exploit an IDOR vulnerability?
A) By brute-forcing login credentials
B) By modifying parameter values in requests (e.g., changing user_id=123 to user_id=456)
C) By executing malicious scripts on a vulnerable website
D) By launching denial-of-service (DoS) attacks
Answer: B) By modifying parameter values in requests (e.g., changing user_id=123 to user_id=456)
Explanation: Attackers exploit IDOR by changing request parameters to access unauthorized objects, such as viewing or modifying other users’ data.
6. Which HTTP methods are commonly associated with IDOR vulnerabilities?
A) GET and POST
B) HEAD and TRACE
C) CONNECT and OPTIONS
D) PATCH and DELETE
Answer: A) GET and POST
Explanation: IDOR is often found in applications using GET and POST methods where user-controllable parameters reference objects (e.g., GET /profile?id=123).
7. What is a practical example of an IDOR vulnerability?
A) Changing invoice_id=1001 in a URL to invoice_id=1002 and accessing another user’s invoice
B) Sending a phishing email to gain login credentials
C) Using SQL Injection to retrieve database contents
D) Exploiting a weak password reset mechanism
Answer: A) Changing invoice_id=1001 in a URL to invoice_id=1002 and accessing another user’s invoice
Explanation: If an application does not properly enforce access control, an attacker can modify parameters to access unauthorized data.
8. What is the best way to detect IDOR vulnerabilities in a web application?
A) Running automated vulnerability scanners
B) Performing manual testing by modifying request parameters
C) Checking for outdated SSL/TLS certificates
D) Monitoring server response times
Answer: B) Performing manual testing by modifying request parameters
Explanation: While automated tools can help, manual testing is essential for identifying IDOR vulnerabilities by tampering with request parameters.
9. Which OWASP category does IDOR belong to?
A) A1: Injection
B) A2: Broken Authentication
C) A5: Security Misconfiguration
D) A1: Broken Access Control
Answer: D) A1: Broken Access Control
Explanation: OWASP classifies IDOR under Broken Access Control, as it allows unauthorized access to sensitive data.
10. Which tool can be used to test for IDOR vulnerabilities?
A) Nmap
B) Burp Suite
C) Wireshark
D) Hashcat
Answer: B) Burp Suite
Explanation: Burp Suite allows security testers to intercept and modify HTTP requests, making it useful for identifying IDOR vulnerabilities.
11. What is a typical remediation step for preventing IDOR?
A) Hashing URLs to make them unreadable
B) Implementing proper authorization checks on object access
C) Using HTTPS instead of HTTP
D) Blocking all external IP addresses
Answer: B) Implementing proper authorization checks on object access
Explanation: Ensuring that users can only access objects they are authorized to view is the best way to mitigate IDOR vulnerabilities.
12. How can developers verify that an IDOR vulnerability is fixed?
A) By implementing two-factor authentication (2FA)
B) By testing unauthorized access attempts using different user roles
C) By switching from GET to POST requests
D) By encrypting all client-side JavaScript
Answer: B) By testing unauthorized access attempts using different user roles
Explanation: Proper role-based testing ensures that unauthorized users cannot access restricted resources.
13. What is an example of indirect IDOR exploitation?
A) Exploiting an API that fetches sensitive data for another user without authorization
B) Changing the ID in the URL manually
C) Using phishing techniques to trick users
D) Exploiting weak passwords to gain unauthorized access
Answer: A) Exploiting an API that fetches sensitive data for another user without authorization
Explanation: An API may fetch sensitive data based on user-supplied IDs, leading to IDOR exploitation if authorization checks are missing.
14. What is a key risk of IDOR vulnerabilities?
A) Increased website loading time
B) Unauthorized access to sensitive user data
C) Slower server response time
D) Excessive memory usage
Answer: B) Unauthorized access to sensitive user data
Explanation: IDOR can lead to data leaks, privilege escalation, and security breaches.
15. Can API endpoints have IDOR vulnerabilities?
A) Yes, if authorization checks are not enforced
B) No, APIs are always secure
C) Only if the API uses HTTP instead of HTTPS
D) Only if the API is accessible over the internet
Answer: A) Yes, if authorization checks are not enforced
Explanation: APIs that rely on user-inputted IDs without verifying access control are prone to IDOR.
16. How can encryption help mitigate IDOR?
A) By preventing request tampering
B) By making URLs unreadable
C) By protecting data at rest
D) Encryption alone does not prevent IDOR
Answer: D) Encryption alone does not prevent IDOR
Explanation: While encryption secures data, proper access controls are needed to prevent IDOR.
17. What is a business impact of an IDOR exploit?
A) Website performance degradation
B) Unauthorized access to sensitive data, leading to compliance violations
C) Increased power consumption
D) Better user experience
Answer: B) Unauthorized access to sensitive data, leading to compliance violations
Explanation: IDOR exploits can result in GDPR violations, data breaches, and reputational damage.
18. What is a common misconception about IDOR?
A) It only affects small websites
B) It can only be exploited through URLs
C) It requires complex hacking skills
D) It can be found in APIs, web applications, and mobile apps
Answer: D) It can be found in APIs, web applications, and mobile apps
Explanation: IDOR can exist anywhere object references are exposed without proper authorization.
19. Which of the following is a real-world consequence of an IDOR vulnerability?
A) A hacker changing the price of an item during an online transaction
B) A company experiencing slow website loading times
C) An attacker redirecting users to a malicious website
D) A website showing ads based on user behavior
Answer: A) A hacker changing the price of an item during an online transaction
Explanation: If IDOR is present in a shopping cart or order management system, attackers can modify parameters to change prices or get discounts.
20. What type of authentication is NOT effective alone in preventing IDOR vulnerabilities?
A) Multi-Factor Authentication (MFA)
B) Role-Based Access Control (RBAC)
C) JSON Web Tokens (JWT)
D) Encryption
Answer: D) Encryption
Explanation: Encryption protects data confidentiality but does not enforce access control. Proper authorization is necessary to prevent IDOR.
21. Which of the following is an effective way to prevent IDOR in REST APIs?
A) Using rate-limiting to block multiple requests
B) Enforcing user-specific permission checks on every request
C) Obfuscating object references
D) Storing all sensitive data client-side
Answer: B) Enforcing user-specific permission checks on every request
Explanation: Checking whether a user is authorized to access an object before returning data prevents IDOR in APIs.
22. How does using UUIDs (Universally Unique Identifiers) impact IDOR vulnerabilities?
A) It completely eliminates IDOR risks
B) It makes IDOR exploitation more difficult but does not prevent it
C) It makes object references guessable
D) It allows attackers to brute-force access more easily
Answer: B) It makes IDOR exploitation more difficult but does not prevent it
Explanation: While UUIDs are harder to guess than sequential IDs, they do not enforce access control, so IDOR may still be possible.
23. Which HTTP response status code indicates that an IDOR attempt was blocked?
A) 200 OK
B) 302 Found
C) 403 Forbidden
D) 500 Internal Server Error
Answer: C) 403 Forbidden
Explanation: A 403 error means access is denied due to missing authorization, which is the correct behavior for blocking IDOR attempts.
24. How can penetration testers automate the detection of IDOR vulnerabilities?
A) By using CAPTCHA-solving scripts
B) By employing tools like Burp Suite Intruder and Fuzzers
C) By running SQL Injection queries
D) By using command injection exploits
Answer: B) By employing tools like Burp Suite Intruder and Fuzzers
Explanation: Burp Suite Intruder, OWASP ZAP, and custom fuzzers can automate ID modification tests to identify IDOR vulnerabilities.
25. Which security framework recommends “Deny by Default” policies to mitigate IDOR?
A) OWASP
B) GDPR
C) ITIL
D) ISO 9001
Answer: A) OWASP
Explanation: OWASP security best practices suggest using a Deny by Default approach, meaning users must be explicitly granted access.
26. In which scenario is IDOR least likely to occur?
A) A mobile banking app without access control verification
B) A forum where users can modify their post ID to edit others’ posts
C) A file-sharing platform where users can change the file ID to access private documents
D) A static website with only publicly available HTML files
Answer: D) A static website with only publicly available HTML files
Explanation: IDOR affects dynamic applications that process user-controlled object references, not static websites.
27. What is the best testing approach to uncover IDOR vulnerabilities?
A) Running vulnerability scanners only
B) Reviewing source code for missing authorization checks
C) Only checking for exposed database credentials
D) Sending phishing emails to employees
Answer: B) Reviewing source code for missing authorization checks
Explanation: IDOR vulnerabilities often stem from missing authorization logic, which is best found via source code analysis.
28. How does an attacker escalate privileges using IDOR?
A) By modifying an object reference to gain access to admin resources
B) By logging in with multiple accounts
C) By using weak passwords
D) By exploiting network traffic
Answer: A) By modifying an object reference to gain access to admin resources
Explanation: Attackers change object IDs to access higher-privileged accounts, escalating their privileges.
29. Which programming language is most susceptible to IDOR vulnerabilities?
A) Java
B) Python
C) JavaScript
D) Any language that does not enforce proper access control
Answer: D) Any language that does not enforce proper access control
Explanation: IDOR is a logic flaw, not a language-specific issue. It occurs in any language if access control is weak.
30. What is a common error developers make that leads to IDOR?
A) Storing user data in encrypted form
B) Using client-side authorization checks only
C) Implementing logging mechanisms
D) Using secure cookies
Answer: B) Using client-side authorization checks only
Explanation: Client-side checks can be bypassed, so server-side authorization is required.
31. How can organizations monitor for IDOR exploitation attempts?
A) By checking error logs for unusual “403 Forbidden” responses
B) By blocking all incoming requests from foreign IPs
C) By requiring users to reset passwords frequently
D) By disabling session cookies
Answer: A) By checking error logs for unusual “403 Forbidden” responses
Explanation: Repeated 403 errors with different object IDs may indicate automated IDOR attack attempts.
32. Which of the following is a security misconfiguration that can lead to IDOR?
A) Enabling brute-force protection
B) Allowing unrestricted access to sensitive APIs
C) Using HTTPS instead of HTTP
D) Implementing CAPTCHA on login pages
Answer: B) Allowing unrestricted access to sensitive APIs
Explanation: APIs that do not enforce proper authentication and authorization are prone to IDOR.
33. Which role is responsible for mitigating IDOR risks in a company?
A) Only the Security Team
B) Only the Development Team
C) Both Developers and Security Teams
D) The Legal Department
Answer: C) Both Developers and Security Teams
Explanation: Developers must enforce authorization and security teams must test for vulnerabilities.
34. How does rate limiting help against IDOR attacks?
A) It prevents users from modifying URLs
B) It slows down brute-force attempts to discover valid object IDs
C) It forces users to enter CAPTCHA before each request
D) It replaces object references with encrypted tokens
Answer: B) It slows down brute-force attempts to discover valid object IDs
Explanation: Rate limiting restricts how quickly attackers can brute-force object IDs.
35. What happens if an application does not validate session tokens along with object references?
A) It becomes vulnerable to session fixation attacks
B) It allows IDOR by exposing data to unauthorized users
C) It automatically blocks unauthorized requests
D) It improves website performance
Answer: B) It allows IDOR by exposing data to unauthorized users
Explanation: Without session validation, users can modify object references to access other users’ data.
36. What type of testing is most effective in identifying IDOR vulnerabilities?
A) Load testing
B) Fuzz testing
C) Black-box testing
D) White-box testing
Answer: D) White-box testing
Explanation: White-box testing involves reviewing the application’s source code, making it highly effective for finding authorization logic flaws like IDOR.
37. What can an attacker gain by exploiting an IDOR vulnerability in a medical system?
A) Direct access to modify hospital network configurations
B) Unauthorized access to other patients’ sensitive health records
C) The ability to install ransomware on all medical devices
D) Full administrative control over hospital IT infrastructure
Answer: B) Unauthorized access to other patients’ sensitive health records
Explanation: IDOR vulnerabilities in healthcare applications can expose sensitive patient records, violating HIPAA compliance.
38. Which of the following is an example of preventing IDOR using indirect references?
A) Replacing sequential user IDs with hashed values or GUIDs
B) Obfuscating database queries in the backend
C) Implementing two-factor authentication (2FA)
D) Allowing users to access their data directly via URL parameters
Answer: A) Replacing sequential user IDs with hashed values or GUIDs
Explanation: Using indirect references (e.g., UUIDs, hashed IDs) makes it harder for attackers to guess and manipulate object references.
39. What kind of API vulnerability does IDOR fall under?
A) API Rate Limiting
B) Insecure API Authentication
C) Broken Object-Level Authorization (BOLA)
D) API Injection
Answer: C) Broken Object-Level Authorization (BOLA)
Explanation: IDOR is a form of BOLA, where API endpoints expose objects without properly checking if the user is authorized to access them.
40. What happens if an application relies only on user-submitted parameters for access control?
A) Users can only access their own data
B) IDOR vulnerabilities can allow unauthorized access to restricted resources
C) The application becomes resistant to brute-force attacks
D) The application will automatically encrypt all user inputs
Answer: B) IDOR vulnerabilities can allow unauthorized access to restricted resources
Explanation: If authorization checks are missing, attackers can modify parameters to access data belonging to other users.
41. How do URL shorteners impact IDOR security?
A) They prevent IDOR vulnerabilities
B) They make object references unreadable but do not prevent unauthorized access
C) They encrypt the URL to secure data
D) They automatically enforce authentication
Answer: B) They make object references unreadable but do not prevent unauthorized access
Explanation: URL shorteners can obscure IDs but do not enforce access control. Attackers can still access resources if they guess the shortened URL.
42. What is the primary security concern when using enumeration-based IDs in URLs?
A) They make database queries faster
B) Attackers can increment IDs to access unauthorized data
C) They prevent brute-force attacks
D) They improve web application performance
Answer: B) Attackers can increment IDs to access unauthorized data
Explanation: Sequential IDs (e.g., user_id=1001, user_id=1002) are predictable and can lead to IDOR exploits if access control is not enforced.
43. How does logging help mitigate IDOR attacks?
A) By tracking unauthorized access attempts
B) By preventing brute-force attacks
C) By encrypting object references
D) By limiting the number of user requests
Answer: A) By tracking unauthorized access attempts
Explanation: Logging unauthorized access attempts (e.g., users trying to modify object IDs) can help detect and respond to IDOR attacks.
44. Why is user authentication alone not enough to prevent IDOR?
A) Because authentication verifies identity but does not enforce authorization
B) Because authentication automatically blocks all unauthorized access
C) Because authentication prevents brute-force attacks
D) Because authentication ensures proper session management
Answer: A) Because authentication verifies identity but does not enforce authorization
Explanation: Authentication only confirms who a user is, while authorization defines what they can access. IDOR occurs when authorization checks are missing.
45. What is a common mistake developers make when securing object access?
A) Checking access control at the database level
B) Relying only on frontend validation to restrict access
C) Using role-based access control (RBAC)
D) Implementing session management correctly
Answer: B) Relying only on frontend validation to restrict access
Explanation: Client-side validation can be bypassed easily. Server-side access control is essential to prevent IDOR.
46. What is the impact of IDOR vulnerabilities on compliance regulations like GDPR?
A) Organizations may face heavy fines for unauthorized data access
B) IDOR does not impact compliance regulations
C) IDOR only affects internal systems, not user data
D) GDPR does not apply to web applications
Answer: A) Organizations may face heavy fines for unauthorized data access
Explanation: GDPR mandates strict data protection. An IDOR breach exposing user data can lead to fines, legal action, and reputational damage.
47. What is a common technique to prevent IDOR in session-based applications?
A) Always store sensitive data in cookies
B) Validate user session and permissions before processing the request
C) Allow users to access only their data without authentication
D) Encrypt database queries
Answer: B) Validate user session and permissions before processing the request
Explanation: Verifying the session and checking authorization ensures users can only access objects they are permitted to view.
48. Which of the following is NOT an IDOR exploitation method?
A) Modifying parameters in GET requests
B) Changing session tokens
C) Tampering with request payloads in APIs
D) Modifying response headers
Answer: D) Modifying response headers
Explanation: IDOR exploits rely on manipulating object references (IDs in URLs, API calls) to access unauthorized data, not response headers.
49. What is the biggest challenge in detecting IDOR vulnerabilities?
A) They are easily found with automated scanners
B) They require manual testing and authorization verification
C) They are only found in legacy applications
D) They are only relevant for admin accounts
Answer: B) They require manual testing and authorization verification
Explanation: Automated scanners often fail to detect IDOR because they do not understand authorization logic, making manual testing essential.
50. Why is encrypting user IDs in URLs not a foolproof method to prevent IDOR?
A) Encryption hides the ID but does not enforce access control
B) Encrypted IDs cannot be decoded
C) Encryption makes the application slower
D) Attackers cannot bypass encryption
Answer: A) Encryption hides the ID but does not enforce access control
Explanation: Even if object references are encrypted, an attacker with valid access can still request and decrypt their own ID, then modify requests to access others’ data if authorization checks are missing.
51. What is a primary reason why IDOR vulnerabilities are common in modern web applications?
A) Increased reliance on third-party authentication
B) Use of API-driven architecture without proper authorization
C) Lack of HTTPS encryption
D) Frequent updates to web frameworks
Answer: B) Use of API-driven architecture without proper authorization
Explanation: APIs often expose object references directly (e.g., GET /orders/{order_id}), and without proper authorization enforcement, IDOR vulnerabilities arise.
52. What makes IDOR vulnerabilities particularly dangerous in financial applications?
A) Attackers can change UI settings
B) Attackers can initiate unauthorized transactions or view confidential financial records
C) Attackers can inject JavaScript into the website
D) Attackers can only affect their own account
Answer: B) Attackers can initiate unauthorized transactions or view confidential financial records
Explanation: If IDOR exists in banking or e-commerce applications, attackers can modify transaction details, view statements, or manipulate financial data.
53. How does testing for IDOR differ from testing for SQL Injection?
A) IDOR requires authentication while SQL Injection does not
B) IDOR is tested by modifying object references, whereas SQL Injection involves manipulating database queries
C) SQL Injection is only found in APIs
D) IDOR is a client-side vulnerability, whereas SQL Injection is a server-side vulnerability
Answer: B) IDOR is tested by modifying object references, whereas SQL Injection involves manipulating database queries
Explanation: IDOR exploits improper access control, while SQL Injection exploits poor database input sanitization.
54. What is a major concern when IDOR affects an API that processes sensitive medical records?
A) Attackers can steal patient information, violating HIPAA regulations
B) Attackers can execute arbitrary code
C) Attackers can crash the application
D) Attackers can install malware on the database
Answer: A) Attackers can steal patient information, violating HIPAA regulations
Explanation: IDOR in healthcare APIs can expose electronic health records (EHR), leading to compliance violations and legal consequences.
55. What is a sign that an IDOR vulnerability might exist in an application?
A) Presence of security headers in HTTP responses
B) Object references are directly accessible via URLs or API parameters
C) The application enforces two-factor authentication
D) The database encrypts all user data
Answer: B) Object references are directly accessible via URLs or API parameters
Explanation: Directly referencing object IDs without checking authorization is a key indicator of an IDOR vulnerability.
56. How can JSON Web Tokens (JWTs) help prevent IDOR vulnerabilities?
A) By ensuring all requests are encrypted
B) By allowing the server to verify user permissions before granting access
C) By preventing brute-force attacks
D) By making API calls faster
Answer: B) By allowing the server to verify user permissions before granting access
Explanation: JWTs can store user roles/permissions, ensuring only authorized users can access specific objects.
57. How can GraphQL APIs be vulnerable to IDOR?
A) If authorization checks are not enforced for queried objects
B) If SQL queries are injected into GraphQL endpoints
C) If GraphQL does not use HTTPS
D) If GraphQL returns too much data
Answer: A) If authorization checks are not enforced for queried objects
Explanation: GraphQL allows fetching multiple objects in a single request, making IDOR possible if access control is weak.
58. What is the difference between horizontal and vertical privilege escalation via IDOR?
A) Horizontal affects users at the same level, while vertical grants higher privileges
B) Vertical escalation is always detected by firewalls
C) Horizontal IDOR requires admin access
D) There is no difference
Answer: A) Horizontal affects users at the same level, while vertical grants higher privileges
Explanation: Horizontal IDOR allows accessing other users’ data, whereas vertical IDOR lets an attacker escalate privileges (e.g., accessing admin functions).
59. Why is it a bad practice to rely solely on obfuscating object references (e.g., encoding IDs)?
A) Because encoded values can still be reverse-engineered and exploited
B) Because obfuscation improves security
C) Because it requires advanced cryptographic techniques
D) Because it prevents brute-force attacks
Answer: A) Because encoded values can still be reverse-engineered and exploited
Explanation: Encoding does not enforce authorization. Attackers can decode values and access unauthorized data.
60. What tool is commonly used to automate IDOR testing?
A) Hashcat
B) Burp Suite
C) Wireshark
D) Nmap
Answer: B) Burp Suite
Explanation: Burp Suite allows modifying object references in requests, making it useful for testing IDOR vulnerabilities.
61. What is a recommended way to log and detect IDOR exploitation attempts?
A) Tracking failed authorization attempts and analyzing access patterns
B) Disabling logging to improve performance
C) Encrypting all HTTP requests
D) Blocking API access from unknown IPs
Answer: A) Tracking failed authorization attempts and analyzing access patterns
Explanation: Logging unauthorized object access attempts helps detect potential IDOR attacks.
62. In which phase of the Secure Software Development Life Cycle (SDLC) should IDOR prevention be considered?
A) Only during penetration testing
B) Only after the application is deployed
C) Throughout the entire SDLC, especially in design and development phases
D) Only during the maintenance phase
Answer: C) Throughout the entire SDLC, especially in design and development phases
Explanation: IDOR prevention should be integrated from the design phase to post-deployment monitoring.
63. What happens if IDOR is present in a government portal for tax records?
A) Attackers can access and modify other taxpayers’ financial data
B) Attackers can only access their own data
C) Attackers cannot exploit IDOR without admin access
D) Attackers can only view public information
Answer: A) Attackers can access and modify other taxpayers’ financial data
Explanation: IDOR in a government portal can lead to data leaks, fraud, and legal consequences.
64. Why is it important to verify object ownership on the server side?
A) To prevent users from modifying their own profile settings
B) To ensure that users cannot modify or access unauthorized data
C) To improve API response speed
D) To make debugging easier
Answer: B) To ensure that users cannot modify or access unauthorized data
Explanation: Server-side ownership verification ensures that users cannot access objects they don’t own.
65. How can implementing access control lists (ACLs) mitigate IDOR risks?
A) By defining which users or groups can access specific objects
B) By encrypting object IDs
C) By blocking all user requests
D) By only allowing administrator accounts
Answer: A) By defining which users or groups can access specific objects
Explanation: ACLs enforce object-level access control, preventing unauthorized access.
66. What is a “zero trust” approach to preventing IDOR?
A) Allowing all internal users to access any object
B) Assuming no request is trusted and enforcing strict access control
C) Disabling authentication for faster processing
D) Hiding object references but not enforcing authorization
Answer: B) Assuming no request is trusted and enforcing strict access control
Explanation: Zero Trust security requires continuous verification, reducing IDOR risks.
67. How can API rate limiting reduce the impact of an IDOR vulnerability?
A) By preventing brute-force enumeration of object references
B) By blocking all user requests
C) By limiting API responses
D) By increasing application performance
Answer: A) By preventing brute-force enumeration of object references
Explanation: Rate limiting slows down attackers trying to guess valid object references.
68. How does two-factor authentication (2FA) impact IDOR?
A) It does not directly prevent IDOR
B) It encrypts user requests
C) It blocks all unauthorized requests
D) It hides object references
Answer: A) It does not directly prevent IDOR
Explanation: 2FA secures authentication but does not enforce authorization checks needed to prevent IDOR.
69. How does an attacker typically discover an IDOR vulnerability in a web application?
A) By using brute-force attacks to guess database credentials
B) By modifying object IDs in URLs, API requests, or hidden form fields
C) By installing malware on the victim’s machine
D) By sending phishing emails to users
Answer: B) By modifying object IDs in URLs, API requests, or hidden form fields
Explanation: Attackers manually test by changing object references (e.g., ?id=123 → ?id=124) to check for unauthorized access.
70. Which of the following is a best practice to prevent IDOR in a REST API?
A) Storing API keys in cookies
B) Implementing object-level authorization checks on the backend
C) Encrypting all object references
D) Using CAPTCHA to prevent automated requests
Answer: B) Implementing object-level authorization checks on the backend
Explanation: Authorization checks should always be performed server-side to validate if the user has permission to access the requested object.
71. Why is testing with different user roles essential when checking for IDOR vulnerabilities?
A) It helps developers debug API responses
B) Different roles may have unintended access to objects they shouldn’t see
C) It increases website performance
D) It allows testers to brute-force login credentials
Answer: B) Different roles may have unintended access to objects they shouldn’t see
Explanation: Testing with different roles (e.g., admin, user, guest) helps identify cases where access control is missing or misconfigured.
72. Which of the following is an example of an IDOR attack in a multi-tenant SaaS application?
A) A user accessing another company’s confidential invoices by modifying the tenant_id in API requests
B) A user injecting malicious SQL commands into login fields
C) A user installing a keylogger on another user’s machine
D) A user using a VPN to hide their identity
Answer: A) A user accessing another company’s confidential invoices by modifying the tenant_id in API requests
Explanation: Multi-tenant applications should enforce strict access control to prevent users from accessing data belonging to other tenants.
73. What is an effective way to prevent IDOR in modern applications?
A) Replacing all GET requests with POST requests
B) Implementing access control checks based on user permissions
C) Allowing users to modify only their own records
D) Using obfuscated object references in URLs
Answer: B) Implementing access control checks based on user permissions
Explanation: Access control checks must verify if the requesting user is allowed to access the resource before granting access.
74. Why is client-side validation not enough to prevent IDOR vulnerabilities?
A) Attackers can modify client-side validation rules
B) It only works in some programming languages
C) It blocks all unauthorized users automatically
D) It improves page loading speed but does not affect security
Answer: A) Attackers can modify client-side validation rules
Explanation: Client-side validation (e.g., JavaScript checks) can be bypassed easily using developer tools or proxy tools like Burp Suite.
75. What is the potential legal impact of an IDOR vulnerability in an e-commerce application?
A) A lawsuit due to unauthorized access to customer data
B) A minor inconvenience with no consequences
C) A temporary slowdown in website performance
D) A requirement to change the website’s domain name
Answer: A) A lawsuit due to unauthorized access to customer data
Explanation: Unauthorized access to personal data due to IDOR can result in GDPR, CCPA, or PCI DSS violations, leading to fines and lawsuits.
76. Which of the following is NOT a recommended method for preventing IDOR?
A) Using UUIDs instead of sequential user IDs
B) Performing access control checks before returning sensitive data
C) Encrypting object references
D) Storing sensitive user data in localStorage
Answer: D) Storing sensitive user data in localStorage
Explanation: localStorage is insecure, as it can be accessed via cross-site scripting (XSS), making it a poor security choice.
77. How does API logging help detect IDOR attacks?
A) By tracking failed access attempts to restricted resources
B) By automatically blocking all API requests from new users
C) By preventing SQL Injection attacks
D) By enforcing HTTPS encryption
Answer: A) By tracking failed access attempts to restricted resources
Explanation: Logging access attempts helps detect unusual patterns, such as users repeatedly trying different object IDs.
78. What should a bug bounty hunter look for when testing for IDOR vulnerabilities?
A) Ability to modify another user’s data without proper authorization
B) SQL Injection vulnerabilities
C) Hardcoded admin credentials in JavaScript files
D) Hidden HTML comments in the webpage source
Answer: A) Ability to modify another user’s data without proper authorization
Explanation: Bug bounty hunters test if they can access or modify resources by changing request parameters.
79. What is a common issue with using predictable filenames in IDOR-vulnerable applications?
A) Attackers can sequentially guess filenames to access private documents
B) It causes slower API responses
C) It makes the application more vulnerable to phishing
D) It helps prevent unauthorized access
Answer: A) Attackers can sequentially guess filenames to access private documents
Explanation: If filenames or document paths follow predictable patterns, attackers can enumerate files and access restricted content.
80. What role does user session management play in preventing IDOR attacks?
A) It ensures requests are tied to an authenticated session with proper permissions
B) It speeds up user authentication
C) It prevents brute-force attacks
D) It blocks all API access from guest users
Answer: A) It ensures requests are tied to an authenticated session with proper permissions
Explanation: Session management ensures that each user’s actions are properly validated against their access rights.
81. What is a key difference between IDOR and Broken Access Control?
A) IDOR affects only APIs, while Broken Access Control affects only web applications
B) IDOR is a subset of Broken Access Control
C) Broken Access Control requires authentication, whereas IDOR does not
D) IDOR exploits encryption vulnerabilities, whereas Broken Access Control does not
Answer: B) IDOR is a subset of Broken Access Control
Explanation: IDOR is a specific type of Broken Access Control vulnerability, where direct object references allow unauthorized access.
82. How can an attacker exploit IDOR in a file storage system?
A) By modifying file URLs or file IDs to access other users’ files
B) By injecting malicious SQL commands into the login form
C) By sending phishing emails to users
D) By modifying JavaScript code in the browser
Answer: A) By modifying file URLs or file IDs to access other users’ files
Explanation: If a file-sharing system does not validate user access, attackers can access or download files by changing file references.
83. How can penetration testers safely test for IDOR vulnerabilities?
A) By attempting to access unauthorized data with permission from the application owner
B) By running automated SQL Injection scripts
C) By modifying system files on the server
D) By launching a Distributed Denial of Service (DDoS) attack
Answer: A) By attempting to access unauthorized data with permission from the application owner
Explanation: Ethical hacking and penetration testing require permission before testing vulnerabilities like IDOR.
84. Why are mobile applications vulnerable to IDOR attacks?
A) Many mobile apps communicate with APIs that lack proper authorization checks
B) Mobile apps do not use authentication
C) Mobile apps store all data locally
D) Mobile apps are always encrypted
Answer: A) Many mobile apps communicate with APIs that lack proper authorization checks
Explanation: APIs handling user requests in mobile applications must implement authorization controls to prevent IDOR.
85. How can GraphQL queries lead to IDOR vulnerabilities?
A) If access control is not enforced at the resolver level
B) If GraphQL uses GET requests instead of POST
C) If the application does not use a firewall
D) If the API returns data in JSON format
Answer: A) If access control is not enforced at the resolver level
Explanation: GraphQL queries can return multiple objects in one request, making it crucial to enforce authorization checks at the resolver level.
86. How does the principle of “least privilege” help prevent IDOR vulnerabilities?
A) By granting users the minimal access necessary to perform their tasks
B) By allowing all users to access all objects for flexibility
C) By disabling encryption on sensitive objects
D) By preventing API logging
Answer: A) By granting users the minimal access necessary to perform their tasks
Explanation: Limiting user access to only necessary objects and actions reduces the risk of IDOR exploitation.
87. What type of testing is most effective for detecting IDOR vulnerabilities?
A) Static Code Analysis (SAST)
B) Dynamic Application Security Testing (DAST)
C) Unit Testing
D) Performance Testing
Answer: B) Dynamic Application Security Testing (DAST)
Explanation: DAST (such as Burp Suite testing) helps identify IDOR by modifying request parameters dynamically.
88. How does using API gateways improve security against IDOR?
A) By enforcing access control policies before requests reach backend services
B) By encrypting API requests
C) By blocking all unauthenticated requests
D) By speeding up API responses
Answer: A) By enforcing access control policies before requests reach backend services
Explanation: API gateways can verify user roles and permissions before processing requests, reducing IDOR risks.
89. What is a common mistake developers make when trying to prevent IDOR?
A) Using client-side authorization checks instead of server-side validation
B) Logging all unauthorized access attempts
C) Implementing proper Role-Based Access Control (RBAC)
D) Using secure API authentication methods
Answer: A) Using client-side authorization checks instead of server-side validation
Explanation: Client-side checks can be bypassed easily, so server-side validation is required to prevent IDOR.
90. How can multi-tenancy applications be affected by IDOR vulnerabilities?
A) If one tenant can access data belonging to another tenant due to improper access control
B) If users share the same authentication tokens
C) If all tenants are required to use two-factor authentication
D) If the application uses cloud storage
Answer: A) If one tenant can access data belonging to another tenant due to improper access control
Explanation: Multi-tenant applications must implement strict tenant isolation to prevent cross-tenant IDOR attacks.
91. How do attackers commonly exploit IDOR vulnerabilities in REST APIs?
A) By changing object IDs in API requests to access unauthorized data
B) By injecting malicious JavaScript into API endpoints
C) By brute-forcing admin passwords
D) By launching DNS spoofing attacks
Answer: A) By changing object IDs in API requests to access unauthorized data
Explanation: REST APIs often expose object IDs, and without proper authorization checks, attackers can access unauthorized resources.
92. Which compliance standard specifically requires protection against IDOR vulnerabilities?
A) GDPR
B) PCI DSS
C) HIPAA
D) All of the above
Answer: D) All of the above
Explanation: GDPR, PCI DSS, and HIPAA all require proper access control mechanisms to prevent unauthorized access to sensitive data.
93. What is an example of horizontal privilege escalation via IDOR?
A) A regular user modifying a request to access another user’s private data
B) A guest user gaining access to admin-level functions
C) A database administrator modifying a user’s password
D) A user injecting SQL queries into login fields
Answer: A) A regular user modifying a request to access another user’s private data
Explanation: Horizontal privilege escalation occurs when an attacker accesses data belonging to another user at the same privilege level.
94. Why is manually testing for IDOR often necessary, even when using automated scanners?
A) Automated tools may not understand application-specific access control logic
B) Automated scanners detect all security vulnerabilities
C) Manual testing is always faster than automated testing
D) Automated scanners can modify object references automatically
Answer: A) Automated tools may not understand application-specific access control logic
Explanation: IDOR vulnerabilities often require manual validation to ensure authorization is properly enforced.
95. How can session hijacking contribute to an IDOR attack?
A) If an attacker steals a session and then modifies object references to access unauthorized data
B) If a session expires too quickly
C) If a user logs in from multiple devices
D) If a user resets their password
Answer: A) If an attacker steals a session and then modifies object references to access unauthorized data
Explanation: If an attacker gains access to a valid session, they can attempt IDOR attacks within the session’s scope.
96. What is a security risk of allowing users to select object IDs from dropdown menus?
A) Attackers may tamper with the dropdown values to access unauthorized data
B) Dropdown menus are always secure
C) Dropdown menus make IDOR harder to exploit
D) Dropdown menus prevent brute-force attacks
Answer: A) Attackers may tamper with the dropdown values to access unauthorized data
Explanation: If object IDs are predictable, attackers can manipulate them in intercepted requests.
97. What is the best way to enforce object-level security in GraphQL APIs?
A) Checking user permissions at the resolver level
B) Disabling introspection queries
C) Using TLS encryption
D) Rate-limiting all queries
Answer: A) Checking user permissions at the resolver level
Explanation: Authorization must be enforced at the GraphQL resolver level to ensure users only access authorized objects.
98. What role does Content Security Policy (CSP) play in preventing IDOR attacks?
A) CSP prevents unauthorized object access directly
B) CSP helps mitigate Cross-Site Scripting (XSS), which can be used to exploit IDOR vulnerabilities
C) CSP automatically encrypts all object references
D) CSP blocks all API requests
Answer: B) CSP helps mitigate Cross-Site Scripting (XSS), which can be used to exploit IDOR vulnerabilities
Explanation: CSP does not prevent IDOR directly, but it can help block XSS attacks that may facilitate IDOR exploitation.
99. What is a risk associated with exposing user account IDs in email URLs?
A) Attackers can enumerate account IDs and exploit IDOR vulnerabilities
B) Email links always require authentication, so there’s no risk
C) It prevents brute-force attacks
D) It allows users to securely reset their passwords
Answer: A) Attackers can enumerate account IDs and exploit IDOR vulnerabilities
Explanation: If an application does not enforce proper authorization checks, exposing user IDs in emails can lead to IDOR attacks.
100. How can an attacker exploit IDOR in a voting or survey application?
A) By modifying the request to submit multiple votes or access other users’ responses
B) By injecting SQL commands into the login form
C) By launching a brute-force attack on the authentication system
D) By changing their IP address while voting
Answer: A) By modifying the request to submit multiple votes or access other users’ responses
Explanation: IDOR in voting applications can allow attackers to manipulate votes or view restricted survey responses.
101. Why is it important to validate access control on both “read” and “write” operations?
A) Read-only requests cannot be exploited
B) IDOR can occur when users are able to modify or view unauthorized objects
C) Only write operations are vulnerable to IDOR
D) Read access does not require authorization
Answer: B) IDOR can occur when users are able to modify or view unauthorized objects
Explanation: Both read (GET) and write (POST, PUT, DELETE) operations should enforce access control to prevent unauthorized access.
102. How can implementing OAuth improve security against IDOR?
A) OAuth enables token-based access control, reducing reliance on user-controlled parameters
B) OAuth encrypts all API responses
C) OAuth prevents brute-force attacks
D) OAuth forces all users to reset their passwords periodically
Answer: A) OAuth enables token-based access control, reducing reliance on user-controlled parameters
Explanation: OAuth tokens enforce scoped access, ensuring users can only interact with objects they are authorized to access.
103. What is an effective logging strategy for detecting IDOR exploitation attempts?
A) Monitoring logs for repeated access to sequential or unexpected object IDs
B) Disabling logging to improve performance
C) Logging only successful authentication attempts
D) Blocking all API requests that contain numbers in the URL
Answer: A) Monitoring logs for repeated access to sequential or unexpected object IDs
Explanation: Unusual access patterns (e.g., a user attempting different object IDs) can indicate an IDOR attack attempt.
104. How does implementing access tokens for API requests reduce IDOR risks?
A) Tokens ensure that API requests include user identity and permission validation
B) Tokens prevent users from logging in multiple times
C) Tokens make the API run faster
D) Tokens replace object IDs with hashed values
Answer: A) Tokens ensure that API requests include user identity and permission validation
Explanation: Using access tokens ensures that API requests authenticate the user and verify their permissions before granting access.
105. Why is it risky to expose sequential numeric user IDs in URLs?
A) Attackers can increment or decrement IDs to access other users’ data
B) It increases API response times
C) It prevents users from remembering their own user IDs
D) It helps improve performance
Answer: A) Attackers can increment or decrement IDs to access other users’ data
Explanation: Sequential IDs make it easy for attackers to guess other users’ IDs and exploit IDOR vulnerabilities.
106. Which of the following API response behaviors suggests a potential IDOR vulnerability?
A) An API returning data for another user when modifying a request parameter
B) An API returning a 404 error when requesting another user’s data
C) An API requiring authentication before returning data
D) An API encrypting all responses
Answer: A) An API returning data for another user when modifying a request parameter
Explanation: If modifying an object reference in a request retrieves another user’s data, it indicates a likely IDOR vulnerability.
107. How can GraphQL introspection contribute to IDOR vulnerabilities?
A) It allows attackers to discover sensitive object types and relationships
B) It encrypts all API requests
C) It makes authentication stricter
D) It prevents SQL Injection
Answer: A) It allows attackers to discover sensitive object types and relationships
Explanation: Introspection in GraphQL can expose API schema details, helping attackers identify vulnerable object references.
108. How can an attacker exploit IDOR in an online ticket booking system?
A) By modifying the ticket ID in API requests to access other users’ tickets
B) By sending phishing emails to the support team
C) By running a DDoS attack against the ticketing server
D) By using a VPN to hide their identity
Answer: A) By modifying the ticket ID in API requests to access other users’ tickets
Explanation: If the system does not validate user access to tickets, an attacker can modify ticket IDs and view or alter other users’ bookings.
109. What is a critical security risk when exposing object IDs via JavaScript in the frontend?
A) IDs can be easily extracted and manipulated by attackers
B) JavaScript runs only on the client-side, so there’s no security concern
C) JavaScript can prevent IDOR by encrypting requests
D) IDs stored in JavaScript are automatically protected from exploitation
Answer: A) IDs can be easily extracted and manipulated by attackers
Explanation: Attackers can inspect JavaScript variables in the browser and use exposed IDs to attempt IDOR attacks.
110. Why is implementing “deny by default” an effective strategy to prevent IDOR?
A) It ensures that users must be explicitly granted access to objects
B) It allows users to access any object unless explicitly restricted
C) It prevents DDoS attacks
D) It hides object references
Answer: A) It ensures that users must be explicitly granted access to objects
Explanation: The “deny by default” approach ensures that users can only access objects if explicitly authorized, reducing IDOR risks.
111. How can an attacker exploit IDOR in an airline booking system?
A) By changing the booking reference in API requests to view or modify other passengers’ tickets
B) By using SQL Injection in the payment portal
C) By modifying CSS styles in the airline’s website
D) By performing a brute-force attack on flight schedules
Answer: A) By changing the booking reference in API requests to view or modify other passengers’ tickets
Explanation: If the booking system does not validate user access properly, an attacker can modify booking IDs to access other passengers’ information.
112. Which web security framework provides guidance on preventing IDOR vulnerabilities?
A) OWASP
B) ITIL
C) PRINCE2
D) COBIT
Answer: A) OWASP
Explanation: OWASP provides best practices and guidelines to prevent IDOR vulnerabilities through proper access control measures.
113. How can a mobile application be vulnerable to IDOR?
A) If it relies only on local authentication and does not verify API requests on the backend
B) If it uses two-factor authentication (2FA)
C) If it has a slow response time
D) If it encrypts all communication using TLS
Answer: A) If it relies only on local authentication and does not verify API requests on the backend
Explanation: Mobile apps should validate all API requests on the server to ensure proper access control.
114. Why should developers avoid using direct numeric IDs in API requests?
A) Numeric IDs make it easy for attackers to enumerate and manipulate object references
B) Numeric IDs slow down the application
C) Numeric IDs consume more storage
D) Numeric IDs are not compatible with REST APIs
Answer: A) Numeric IDs make it easy for attackers to enumerate and manipulate object references
Explanation: Predictable numeric IDs allow attackers to guess and modify object references, leading to IDOR vulnerabilities.
115. What is a major security risk of using hidden form fields to store object IDs?
A) Attackers can modify form fields before submission and access unauthorized objects
B) It slows down web page rendering
C) It causes session timeouts
D) It prevents users from submitting multiple requests
Answer: A) Attackers can modify form fields before submission and access unauthorized objects
Explanation: Hidden form fields can be easily modified using browser developer tools or proxy tools like Burp Suite.
116. How does HTTP referer logging help detect IDOR attacks?
A) It records the origin of requests, which can help identify unusual access patterns
B) It encrypts API responses
C) It prevents all unauthorized API calls
D) It forces users to authenticate twice
Answer: A) It records the origin of requests, which can help identify unusual access patterns
Explanation: Monitoring HTTP referers can help detect unauthorized access attempts and identify potential IDOR attacks.
117. Why is implementing a UUID (Universally Unique Identifier) instead of a sequential ID not a complete solution for preventing IDOR?
A) UUIDs make IDOR harder to exploit but do not enforce authorization
B) UUIDs are always encrypted
C) UUIDs prevent SQL Injection
D) UUIDs slow down database queries
Answer: A) UUIDs make IDOR harder to exploit but do not enforce authorization
Explanation: UUIDs increase security by making enumeration difficult, but proper authorization checks are still required.
118. What is an advanced method for detecting IDOR vulnerabilities in an API?
A) Performing fuzz testing with Burp Suite Intruder
B) Checking if the application is using HTTPS
C) Running a DDoS attack on the API
D) Using CAPTCHA to prevent enumeration
Answer: A) Performing fuzz testing with Burp Suite Intruder
Explanation: Fuzz testing helps detect IDOR vulnerabilities by automatically modifying object references and checking for unauthorized access.
119. Why is “token-based authorization” effective against IDOR?
A) Tokens store user permissions, ensuring that only authorized users can access specific objects
B) Tokens encrypt user data
C) Tokens prevent phishing attacks
D) Tokens automatically block all unauthorized users
Answer: A) Tokens store user permissions, ensuring that only authorized users can access specific objects
Explanation: Token-based authentication ensures that every API request is properly validated against user permissions.
120. How can an attacker exploit IDOR in a customer support ticketing system?
A) By modifying the ticket ID in requests to view or update another user’s support tickets
B) By executing a cross-site scripting (XSS) attack
C) By using weak passwords to log into customer accounts
D) By downloading all support requests via a public API
Answer: A) By modifying the ticket ID in requests to view or update another user’s support tickets
Explanation: If a support system does not enforce access control, an attacker can modify ticket IDs and access unauthorized support cases.
121. Why is it important to validate user roles when preventing IDOR?
A) To ensure users can only access objects they are authorized for
B) To allow all users to access all resources
C) To improve application speed
D) To prevent users from resetting their passwords
Answer: A) To ensure users can only access objects they are authorized for
Explanation: Role-based access control (RBAC) ensures that users can only interact with resources they have permissions for.
122. How can rate-limiting help mitigate IDOR exploitation?
A) By slowing down automated attempts to guess object references
B) By encrypting all request parameters
C) By forcing users to log in again after each request
D) By blocking all API requests
Answer: A) By slowing down automated attempts to guess object references
Explanation: Rate-limiting reduces the effectiveness of brute-force enumeration attacks on object references.
123. What is a potential risk of exposing internal database IDs in API responses?
A) Attackers can use them to attempt IDOR attacks
B) It improves API performance
C) It increases encryption complexity
D) It allows faster database indexing
Answer: A) Attackers can use them to attempt IDOR attacks
Explanation: If database IDs are predictable, attackers can use them to access unauthorized resources.
124. What security risk arises if session cookies do not expire properly?
A) Attackers can maintain unauthorized access and attempt IDOR attacks
B) Users have to log in too frequently
C) It slows down application performance
D) It prevents users from modifying their data
Answer: A) Attackers can maintain unauthorized access and attempt IDOR attacks
Explanation: Session hijacking combined with IDOR can allow attackers to maintain unauthorized access to sensitive resources.
125. How can penetration testers use session hijacking to enhance IDOR testing?
A) By testing if a hijacked session can access other users’ resources
B) By brute-forcing API endpoints
C) By injecting malicious SQL commands
D) By modifying server configurations
Answer: A) By testing if a hijacked session can access other users’ resources
Explanation: If a hijacked session allows ID modification and unauthorized data access, IDOR vulnerabilities exist.
126. What security measure helps prevent IDOR in file-sharing applications?
A) Implementing object ownership checks before granting file access
B) Hiding file URLs in JavaScript
C) Encrypting all file names
D) Using CAPTCHA before every file download
Answer: A) Implementing object ownership checks before granting file access
Explanation: Validating ownership before allowing access prevents users from retrieving files they don’t own.
127. What security control can prevent IDOR when modifying user profiles?
A) Verifying that the logged-in user can only modify their own profile
B) Disabling profile editing
C) Allowing unrestricted profile modifications
D) Encrypting user input in the frontend
Answer: A) Verifying that the logged-in user can only modify their own profile
Explanation: Proper access control ensures users cannot modify other users’ profile data.
128. How can an attacker exploit IDOR in a subscription-based video streaming platform?
A) By modifying the subscription ID in API requests to access premium content without paying
B) By brute-forcing login credentials
C) By injecting JavaScript into the search bar
D) By using a VPN to change their IP address
Answer: A) By modifying the subscription ID in API requests to access premium content without paying
Explanation: If access control is not properly enforced, an attacker can change subscription IDs and gain access to premium content for free.
129. What is a major risk of allowing user-generated object IDs in API requests?
A) Attackers can supply arbitrary object references and gain unauthorized access
B) It increases server response times
C) It makes database indexing slower
D) It prevents users from accessing their own data
Answer: A) Attackers can supply arbitrary object references and gain unauthorized access
Explanation: Allowing users to modify object IDs without access control enforcement makes applications vulnerable to IDOR.
130. What security flaw occurs if an e-commerce website allows users to change the order ID in a request to modify someone else’s order?
A) IDOR vulnerability
B) Cross-Site Scripting (XSS)
C) SQL Injection
D) Brute-force attack
Answer: A) IDOR vulnerability
Explanation: If an attacker can modify an order ID and access another user’s purchase details, it is an IDOR vulnerability due to improper access control.
131. How can an attacker escalate privileges using IDOR?
A) By modifying a user role ID in a request to gain admin privileges
B) By enabling two-factor authentication
C) By sending a CAPTCHA request to the server
D) By encrypting all API responses
Answer: A) By modifying a user role ID in a request to gain admin privileges
Explanation: IDOR can be used for privilege escalation if the application fails to verify whether a user is allowed to change their role.
132. How can API response filtering prevent IDOR vulnerabilities?
A) By ensuring that users only receive data they are authorized to access
B) By preventing all API requests from external sources
C) By encrypting API responses
D) By limiting the number of API requests per second
Answer: A) By ensuring that users only receive data they are authorized to access
Explanation: API response filtering ensures that users can only retrieve objects they are permitted to access, mitigating IDOR risks.
133. What is a common mistake developers make when implementing access control that leads to IDOR?
A) Relying only on client-side checks for authorization
B) Using a firewall to block unauthorized traffic
C) Encrypting user passwords
D) Logging all authentication attempts
Answer: A) Relying only on client-side checks for authorization
Explanation: Client-side checks can be bypassed, making it essential to enforce authorization on the server side.
134. How can monitoring “Referer” headers help detect IDOR exploitation attempts?
A) By identifying requests originating from unusual sources or referrers
B) By blocking all API calls containing numbers in the URL
C) By preventing users from accessing their own data
D) By logging all password reset attempts
Answer: A) By identifying requests originating from unusual sources or referrers
Explanation: Referer headers can help detect suspicious request patterns that may indicate unauthorized access attempts.
135. How does user session expiration help mitigate IDOR risks?
A) It limits the time an attacker can exploit a hijacked session for unauthorized access
B) It prevents users from logging in multiple times
C) It encrypts object IDs automatically
D) It forces users to change their passwords regularly
Answer: A) It limits the time an attacker can exploit a hijacked session for unauthorized access
Explanation: Session expiration reduces the time window an attacker has to exploit an active session for IDOR attacks.
136. What is a potential risk if a web application allows users to change invoice IDs in the URL to view other customers’ invoices?
A) Exposure of sensitive financial information and privacy violations
B) Slow website performance
C) Increased database storage usage
D) Reduced search engine ranking
Answer: A) Exposure of sensitive financial information and privacy violations
Explanation: IDOR in an invoicing system can expose financial data, leading to compliance violations (e.g., GDPR, PCI DSS).
137. How can a developer test for IDOR vulnerabilities in a secure way?
A) By manually modifying object references while logged in as different users
B) By performing SQL Injection attacks
C) By injecting JavaScript into input fields
D) By sending phishing emails to administrators
Answer: A) By manually modifying object references while logged in as different users
Explanation: Testing different user roles and modifying object references helps developers identify and fix IDOR vulnerabilities.
138. How can implementing multi-tenancy security controls prevent IDOR in SaaS applications?
A) By enforcing tenant isolation to prevent users from accessing other tenants’ data
B) By using CAPTCHAs on login pages
C) By encrypting all database queries
D) By disabling session cookies
Answer: A) By enforcing tenant isolation to prevent users from accessing other tenants’ data
Explanation: Multi-tenancy controls ensure that users can only access data within their own organization, preventing cross-tenant IDOR attacks.
139. Why is a “deny by default” approach effective against IDOR?
A) It ensures users must be explicitly granted access to objects instead of assuming access by default
B) It speeds up API response times
C) It prevents users from logging in multiple times
D) It hides object references from users
Answer: A) It ensures users must be explicitly granted access to objects instead of assuming access by default
Explanation: A deny-by-default strategy ensures access control is explicitly defined, preventing unauthorized access.
140. How can penetration testers detect IDOR vulnerabilities using Burp Suite?
A) By intercepting and modifying object IDs in requests and observing unauthorized access
B) By encrypting API responses
C) By running a network speed test
D) By sending emails to administrators requesting access
Answer: A) By intercepting and modifying object IDs in requests and observing unauthorized access
Explanation: Burp Suite allows testers to modify requests and analyze how object references are handled, helping to detect IDOR vulnerabilities.
141. Why is testing for IDOR particularly important in financial applications?
A) IDOR can allow attackers to manipulate financial transactions
B) IDOR can cause slower payment processing
C) IDOR only affects front-end design
D) IDOR is not a risk in financial applications
Answer: A) IDOR can allow attackers to manipulate financial transactions
Explanation: If access control is weak, attackers can modify transaction IDs and gain unauthorized financial benefits.
142. What is a major risk of exposing invoice numbers in API requests?
A) Attackers can enumerate invoice numbers and view other customers’ billing details
B) It slows down invoice processing
C) It prevents customers from accessing their own invoices
D) It causes database indexing errors
Answer: A) Attackers can enumerate invoice numbers and view other customers’ billing details
Explanation: Without proper authorization, exposing invoice numbers allows attackers to access sensitive financial data.
143. Why does using session-based authentication not fully prevent IDOR?
A) A valid session can still be used to manipulate object references if authorization is weak
B) Session-based authentication encrypts all API responses
C) Sessions prevent all unauthorized access
D) Sessions make applications load faster
Answer: A) A valid session can still be used to manipulate object references if authorization is weak
Explanation: Even with authenticated sessions, IDOR can be exploited if authorization checks are not enforced on objects.
144. What should an API return when a user requests an object they are not authorized to access?
A) 403 Forbidden
B) 200 OK with an empty response
C) 500 Internal Server Error
D) 302 Redirect
Answer: A) 403 Forbidden
Explanation: A 403 Forbidden response properly indicates that a user is authenticated but lacks permission to access the requested object.
145. How can automated security tools help detect IDOR vulnerabilities?
A) By identifying object reference changes in HTTP requests and checking authorization enforcement
B) By encrypting all API responses
C) By blocking all unknown user requests
D) By modifying CSS elements
Answer: A) By identifying object reference changes in HTTP requests and checking authorization enforcement
Explanation: Automated tools like Burp Suite can detect IDOR by modifying object IDs and checking if unauthorized access is possible.
146. Why is it important to check both GET and POST requests for IDOR vulnerabilities?
A) Both methods can be used to retrieve or modify unauthorized objects
B) GET requests are always secure, but POST requests are not
C) Only POST requests can be exploited
D) GET requests do not require authentication
Answer: A) Both methods can be used to retrieve or modify unauthorized objects
Explanation: IDOR can be exploited via both GET (viewing unauthorized data) and POST (modifying unauthorized data) requests.
147. What security flaw exists if a web application allows a user to reset another user’s password by modifying the user ID in a request?
A) IDOR vulnerability
B) Cross-Site Request Forgery (CSRF)
C) SQL Injection
D) Server-Side Request Forgery (SSRF)
Answer: A) IDOR vulnerability
Explanation: If an attacker can change a user ID and reset another user’s password, it is an IDOR exploit due to missing access control checks.
148. How does implementing API scopes help prevent IDOR?
A) By defining specific permissions for each API request based on user roles
B) By preventing users from logging in multiple times
C) By encrypting all JSON responses
D) By forcing CAPTCHA on all API requests
Answer: A) By defining specific permissions for each API request based on user roles
Explanation: API scopes ensure that users can only perform actions within their permission level, preventing unauthorized object access.
149. What is an effective way to prevent IDOR in a user profile system?
A) Enforcing server-side validation to ensure users can only modify their own profiles
B) Disabling password reset functionality
C) Hiding user profile links in the UI
D) Allowing all users to access any profile for convenience
Answer: A) Enforcing server-side validation to ensure users can only modify their own profiles
Explanation: Access control checks on the server ensure users cannot modify other users’ profile information.
150. What is a real-world consequence of an IDOR vulnerability in a healthcare application?
A) Exposure of private medical records, violating HIPAA compliance
B) Slower website performance
C) A minor inconvenience with no legal impact
D) Faster database queries
Answer: A) Exposure of private medical records, violating HIPAA compliance
Explanation: Unauthorized access to medical records due to IDOR can result in legal penalties and loss of patient trust.
151. How does hashing object references improve security against IDOR?
A) It makes object references harder to guess but does not enforce access control
B) It automatically prevents all unauthorized access
C) It prevents brute-force attacks
D) It encrypts API responses
Answer: A) It makes object references harder to guess but does not enforce access control
Explanation: Hashing or obfuscating IDs makes them harder to predict, but access control must still be enforced.
152. How can an attacker bypass a weak IDOR mitigation that relies on obfuscating object IDs?
A) By using enumeration attacks to discover valid object references
B) By modifying CSS files in the browser
C) By switching browsers frequently
D) By using a VPN
Answer: A) By using enumeration attacks to discover valid object references
Explanation: If object references are only obfuscated, attackers can still enumerate valid values through trial and error.
153. What is an example of IDOR leading to financial fraud?
A) An attacker modifying transaction IDs to access another user’s payment details
B) An attacker changing their browser theme
C) An attacker sending phishing emails
D) An attacker clearing their browser cookies
Answer: A) An attacker modifying transaction IDs to access another user’s payment details
Explanation: IDOR can allow attackers to manipulate financial transactions or access payment records.
154. How does implementing per-object permissions help mitigate IDOR risks?
A) By ensuring users are explicitly authorized for each object they access
B) By forcing two-factor authentication on all API requests
C) By encrypting all request headers
D) By logging all failed login attempts
Answer: A) By ensuring users are explicitly authorized for each object they access
Explanation: Per-object permissions ensure that users can only access the resources they have explicit rights to.
155. Why is reviewing access logs important for detecting IDOR attacks?
A) Logs can reveal unauthorized access attempts or unusual request patterns
B) Logs automatically prevent all unauthorized access
C) Logging improves website speed
D) Logs reduce the need for encryption
Answer: A) Logs can reveal unauthorized access attempts or unusual request patterns
Explanation: Monitoring logs for unauthorized object access can help detect and respond to IDOR attacks.
156. What is an IDOR vulnerability that affects administrative dashboards?
A) If a non-admin user can modify admin panel settings by changing an object ID
B) If the dashboard loads slowly
C) If the dashboard uses HTTPS
D) If the dashboard requires two-factor authentication
Answer: A) If a non-admin user can modify admin panel settings by changing an object ID
Explanation: An IDOR vulnerability in an admin dashboard can allow unauthorized users to escalate privileges and modify system settings.
157. What is a key security risk when exposing API keys in client-side JavaScript?
A) Attackers can use them to manipulate API requests, including IDOR exploits
B) It improves website performance
C) It encrypts API responses automatically
D) It prevents unauthorized access
Answer: A) Attackers can use them to manipulate API requests, including IDOR exploits
Explanation: Exposing API keys publicly allows attackers to modify object references and potentially exploit IDOR vulnerabilities.
158. What is a potential consequence of an IDOR vulnerability in an employee management system?
A) Unauthorized users can view or modify other employees’ payroll and personal details
B) It slows down employee login times
C) It improves database performance
D) It forces employees to change their passwords regularly
Answer: A) Unauthorized users can view or modify other employees’ payroll and personal details
Explanation: IDOR in an employee management system can lead to serious privacy violations and data breaches.
159. What is an effective way to test for IDOR vulnerabilities in a document management system?
A) Modifying document IDs in API requests to check for unauthorized access
B) Trying SQL Injection in the login form
C) Encrypting all document URLs
D) Modifying CSS properties
Answer: A) Modifying document IDs in API requests to check for unauthorized access
Explanation: If an attacker can access another user’s document by changing the document ID, the system is vulnerable to IDOR.
160. How does enforcing ownership checks on the server side help prevent IDOR?
A) It ensures users can only access objects they own or are authorized to access
B) It encrypts all API responses
C) It forces all users to log out after each session
D) It disables all API calls from unknown IPs
Answer: A) It ensures users can only access objects they own or are authorized to access
Explanation: Validating object ownership on the server side prevents users from modifying IDs to access unauthorized objects.
161. What type of penetration testing should be performed to detect IDOR vulnerabilities?
A) Authorization testing to check if users can access unauthorized objects
B) Performance testing to check server speed
C) Load testing to check traffic capacity
D) Phishing simulations to test user awareness
Answer: A) Authorization testing to check if users can access unauthorized objects
Explanation: Penetration testers check whether users can modify parameters to access or modify other users’ data.
162. What is an IDOR vulnerability specific to customer loyalty programs?
A) Users modifying reward points in API requests to increase their balance
B) Users changing their account passwords
C) Users downloading transaction history
D) Users verifying their phone numbers
Answer: A) Users modifying reward points in API requests to increase their balance
Explanation: If an attacker can alter reward point balances by modifying object IDs, the loyalty program is vulnerable to IDOR.
163. How does disabling directory listing in web servers help prevent IDOR exploitation?
A) It prevents attackers from discovering valid object references through open directories
B) It makes the website load faster
C) It prevents all unauthorized API requests
D) It blocks brute-force login attempts
Answer: A) It prevents attackers from discovering valid object references through open directories
Explanation: Directory listing can expose object references that attackers can use to attempt IDOR exploits.
164. Why is encrypting user IDs not a complete solution to IDOR?
A) Encryption does not enforce access control; proper authorization is still required
B) Encrypted IDs prevent all unauthorized access
C) Encryption makes applications faster
D) Encrypted IDs automatically expire after a session ends
Answer: A) Encryption does not enforce access control; proper authorization is still required
Explanation: Even if object references are encrypted, attackers may still access unauthorized data if authorization checks are missing.
165. How can an attacker abuse IDOR in an e-learning platform?
A) By modifying course enrollment IDs to access paid courses for free
B) By changing their profile picture
C) By sending a message to customer support
D) By logging in from a new device
Answer: A) By modifying course enrollment IDs to access paid courses for free
Explanation: IDOR in an e-learning platform can allow unauthorized access to premium courses if proper access control is not enforced.
166. What kind of API response suggests a possible IDOR vulnerability?
A) Returning data for a different user after modifying an object ID in the request
B) Returning a 403 Forbidden error for unauthorized access attempts
C) Encrypting all responses by default
D) Logging out inactive users
Answer: A) Returning data for a different user after modifying an object ID in the request
Explanation: If modifying an object reference returns another user’s data, the API likely lacks proper authorization checks.
167. How does implementing Multi-Factor Authentication (MFA) impact IDOR vulnerabilities?
A) MFA secures authentication but does not prevent IDOR vulnerabilities
B) MFA automatically blocks all unauthorized API requests
C) MFA encrypts all user data
D) MFA prevents all brute-force attacks
Answer: A) MFA secures authentication but does not prevent IDOR vulnerabilities
Explanation: MFA strengthens authentication but does not replace proper access control, which is required to prevent IDOR.
168. What is a key risk of using wildcard permissions in API authorization?
A) It may unintentionally allow access to unauthorized objects
B) It increases API response time
C) It requires two-factor authentication
D) It prevents all unauthorized access
Answer: A) It may unintentionally allow access to unauthorized objects
Explanation: Using wildcard permissions (e.g., * or ALL) can result in users gaining unintended access to sensitive data.
169. How can penetration testers automate IDOR testing?
A) By using Burp Suite Intruder to fuzz object references
B) By encrypting all API requests
C) By manually modifying URLs in the browser
D) By logging out and logging in repeatedly
Answer: A) By using Burp Suite Intruder to fuzz object references
Explanation: Burp Suite Intruder can automate ID modification testing, helping detect IDOR vulnerabilities efficiently.
170. What is a major security risk of exposing a “download URL” for invoices without authentication?
A) Attackers can enumerate invoice IDs and download invoices for other users
B) Users can download their own invoices
C) It speeds up invoice access
D) It prevents API brute-force attacks
Answer: A) Attackers can enumerate invoice IDs and download invoices for other users
Explanation: Publicly accessible download links without authentication allow attackers to enumerate and access private documents.
171. What is a major risk of exposing user profile IDs in a public API without authentication?
A) Attackers can modify profile IDs to access other users’ private information
B) It improves API response speed
C) It prevents unauthorized access
D) It ensures users can modify their own profiles
Answer: A) Attackers can modify profile IDs to access other users’ private information
Explanation: Without authentication and authorization, attackers can manipulate profile IDs to view or modify unauthorized data.
172. How can an attacker exploit IDOR in a referral program?
A) By modifying referral codes to claim rewards for another user’s referral
B) By clicking on multiple referral links
C) By sharing referral links on social media
D) By resetting their password frequently
Answer: A) By modifying referral codes to claim rewards for another user’s referral
Explanation: IDOR in a referral system can allow attackers to modify referral codes and claim unauthorized benefits.
173. What is a key reason why IDOR vulnerabilities are hard to detect using automated scanners?
A) Automated scanners often fail to understand business logic and authorization rules
B) Automated scanners detect all security vulnerabilities automatically
C) Automated scanners cannot send requests to APIs
D) Automated scanners only check for authentication issues
Answer: A) Automated scanners often fail to understand business logic and authorization rules
Explanation: IDOR vulnerabilities require manual testing because automated tools cannot always determine access control flaws.
174. Why is logging unsuccessful access attempts important in detecting IDOR attacks?
A) It helps identify patterns of unauthorized access attempts
B) It automatically prevents all IDOR vulnerabilities
C) It slows down the application
D) It encrypts all request headers
Answer: A) It helps identify patterns of unauthorized access attempts
Explanation: Logging unauthorized object access attempts helps security teams detect and respond to IDOR attacks.
175. How can attackers exploit IDOR in an e-wallet or online banking system?
A) By modifying transaction IDs to transfer money from another user’s account
B) By setting a weak password
C) By logging out frequently
D) By enabling two-factor authentication
Answer: A) By modifying transaction IDs to transfer money from another user’s account
Explanation: If transaction authorization checks are weak, attackers can change transaction IDs and access unauthorized financial transactions.
176. What security misconfiguration increases the risk of IDOR in an API?
A) Allowing users to access all objects without verifying ownership
B) Using two-factor authentication
C) Encrypting API responses
D) Implementing rate-limiting
Answer: A) Allowing users to access all objects without verifying ownership
Explanation: APIs must validate user permissions before granting access to ensure objects are not accessible to unauthorized users.
177. How can GraphQL introspection contribute to IDOR vulnerabilities?
A) It allows attackers to discover object relationships and query sensitive data
B) It prevents unauthorized API access
C) It forces authentication before data access
D) It encrypts all API responses
Answer: A) It allows attackers to discover object relationships and query sensitive data
Explanation: GraphQL introspection can expose API schema details, helping attackers identify potential IDOR vulnerabilities.
178. How can implementing row-level security (RLS) help prevent IDOR?
A) By ensuring each user can only access the database rows they are authorized to see
B) By forcing users to log out after each request
C) By encrypting object references
D) By preventing users from modifying their own data
Answer: A) By ensuring each user can only access the database rows they are authorized to see
Explanation: Row-Level Security (RLS) enforces data access rules at the database level, reducing IDOR risks.
179. What is a common IDOR vulnerability in online booking systems?
A) Users modifying booking IDs to access or cancel another customer’s reservation
B) Users logging in from multiple devices
C) Users downloading their booking receipts
D) Users searching for available flights
Answer: A) Users modifying booking IDs to access or cancel another customer’s reservation
Explanation: If access control is missing, attackers can manipulate booking IDs to change or access another user’s reservation.
180. What is the risk of using predictable object references in a multi-tenant SaaS platform?
A) Attackers can switch tenant IDs to access another organization’s data
B) It improves API response speed
C) It forces users to change their passwords
D) It prevents brute-force attacks
Answer: A) Attackers can switch tenant IDs to access another organization’s data
Explanation: Predictable tenant IDs can lead to cross-tenant data exposure in SaaS applications if proper access control is not enforced.
181. Why is rate limiting not a sufficient solution for preventing IDOR?
A) It slows down brute-force attacks but does not enforce authorization
B) It automatically blocks all unauthorized access
C) It encrypts all API responses
D) It replaces authentication
Answer: A) It slows down brute-force attacks but does not enforce authorization
Explanation: Rate limiting helps reduce attack speed but does not replace proper access control mechanisms.
182. How can API gateways help prevent IDOR?
A) By enforcing authentication and authorization before requests reach backend services
B) By increasing API response speed
C) By allowing unauthenticated users to access all objects
D) By logging user IP addresses
Answer: A) By enforcing authentication and authorization before requests reach backend services
Explanation: API gateways can validate requests before they reach the backend, preventing unauthorized access attempts.
183. What is a key security concern when using JWTs (JSON Web Tokens) for authorization?
A) If JWTs are not validated properly, attackers can manipulate them to bypass access control
B) JWTs automatically encrypt all API responses
C) JWTs prevent all unauthorized access
D) JWTs are only used for authentication
Answer: A) If JWTs are not validated properly, attackers can manipulate them to bypass access control
Explanation: If JWTs are not correctly validated, attackers can alter them to gain unauthorized access to protected resources.
184. Why should API responses avoid revealing detailed error messages related to access control?
A) Detailed errors can help attackers map out authorization logic and exploit IDOR vulnerabilities
B) Error messages make debugging harder
C) Error messages reduce API response speed
D) API responses should always provide detailed user feedback
Answer: A) Detailed errors can help attackers map out authorization logic and exploit IDOR vulnerabilities
Explanation: Error messages that reveal authorization logic can give attackers insights into how to exploit IDOR vulnerabilities.
185. What is a common IDOR risk in e-commerce shopping carts?
A) Users modifying product IDs to change item prices or quantities without authorization
B) Users adding items to their own cart
C) Users searching for products
D) Users reviewing their order history
Answer: A) Users modifying product IDs to change item prices or quantities without authorization
Explanation: If price modification is possible through ID manipulation, attackers can exploit IDOR to alter purchases.
186. What is the benefit of enforcing “deny by default” access control policies?
A) It ensures users must be explicitly granted access before retrieving or modifying data
B) It allows all users to access any resource by default
C) It speeds up API performance
D) It prevents all authentication issues
Answer: A) It ensures users must be explicitly granted access before retrieving or modifying data
Explanation: A “deny by default” approach ensures strict authorization policies, reducing the risk of IDOR.
187. What is a major security risk if an API does not verify user ownership before returning requested data?
A) Attackers can access other users’ sensitive data by modifying object IDs
B) Users can only access their own data
C) The API will return a 500 Internal Server Error
D) The API will encrypt all responses
Answer: A) Attackers can access other users’ sensitive data by modifying object IDs
Explanation: If ownership validation is missing, attackers can manipulate object references to retrieve unauthorized data.
188. How can attackers exploit IDOR in an HR management system?
A) By modifying employee IDs to view or edit confidential employee records
B) By using weak passwords
C) By enabling two-factor authentication
D) By logging in from multiple devices
Answer: A) By modifying employee IDs to view or edit confidential employee records
Explanation: If proper access control is not enforced, attackers can change employee IDs to access HR data they shouldn’t see.
189. What is an effective mitigation strategy for preventing IDOR in API endpoints?
A) Implementing role-based access control (RBAC) to restrict access to sensitive objects
B) Allowing unrestricted access to API endpoints
C) Using CAPTCHA on all API requests
D) Encrypting API request headers
Answer: A) Implementing role-based access control (RBAC) to restrict access to sensitive objects
Explanation: RBAC ensures that only users with the appropriate permissions can access specific resources, reducing IDOR risks.
190. Why should authorization be enforced at the server side rather than the client side?
A) Client-side checks can be bypassed using developer tools or proxies
B) Client-side validation prevents all unauthorized access
C) Client-side validation encrypts all user data
D) Server-side authorization slows down applications
Answer: A) Client-side checks can be bypassed using developer tools or proxies
Explanation: Attackers can manipulate client-side code, so authorization must be enforced on the server to be effective.
191. What is a risk of using user-controllable parameters in file download URLs?
A) Attackers can change file paths to access unauthorized files
B) Users can download their own files
C) It speeds up file retrieval
D) It prevents unauthorized file access
Answer: A) Attackers can change file paths to access unauthorized files
Explanation: If file download links are based on user-modifiable parameters, attackers can manipulate them to access other users’ files.
192. How does implementing an allowlist improve security against IDOR?
A) It ensures only authorized object references can be accessed
B) It blocks all unauthorized users from logging in
C) It forces password resets every 30 days
D) It prevents database queries from executing
Answer: A) It ensures only authorized object references can be accessed
Explanation: An allowlist defines valid object references, preventing unauthorized access attempts.
193. How can an attacker exploit IDOR in an insurance claim system?
A) By modifying claim IDs in requests to access or edit another user’s claim details
B) By requesting a password reset
C) By using a VPN to mask their location
D) By checking their own claim status
Answer: A) By modifying claim IDs in requests to access or edit another user’s claim details
Explanation: If claim processing lacks proper access control, attackers can modify claim IDs to access other users’ insurance claims.
194. Why is implementing least privilege access control important in preventing IDOR?
A) It ensures users can only access objects necessary for their role
B) It speeds up API response times
C) It prevents brute-force attacks
D) It removes the need for authentication
Answer: A) It ensures users can only access objects necessary for their role
Explanation: The principle of least privilege limits access to only what’s necessary, reducing the risk of IDOR exploitation.
195. What is a major concern with exposing GraphQL APIs to unauthenticated users?
A) Attackers can explore object relationships and access sensitive data
B) GraphQL APIs do not support authentication
C) GraphQL APIs automatically prevent IDOR
D) Exposing GraphQL APIs makes applications run faster
Answer: A) Attackers can explore object relationships and access sensitive data
Explanation: GraphQL introspection can reveal object relationships, which can lead to IDOR vulnerabilities if proper access control is not enforced.
196. Why should developers avoid relying solely on obfuscation to prevent IDOR?
A) Obfuscated values can still be reverse-engineered, making IDOR possible
B) Obfuscation encrypts all user data
C) Obfuscation prevents brute-force attacks
D) Obfuscation makes applications run faster
Answer: A) Obfuscated values can still be reverse-engineered, making IDOR possible
Explanation: Obfuscation makes it harder but does not prevent IDOR; proper authorization must still be implemented.
197. What is an IDOR vulnerability that affects vehicle tracking systems?
A) Attackers modifying vehicle IDs to track another person’s car location
B) Attackers modifying their own vehicle’s settings
C) Attackers adjusting seat preferences remotely
D) Attackers switching between different tracking apps
Answer: A) Attackers modifying vehicle IDs to track another person’s car location
Explanation: If access control is not enforced, attackers can change vehicle IDs in API requests to track other people’s locations.
198. Why is session-based authorization alone insufficient to prevent IDOR?
A) A valid session can still be used to access unauthorized objects if authorization checks are missing
B) Session-based authorization prevents all unauthorized access
C) Sessions encrypt all API requests automatically
D) Session-based authorization makes applications faster
Answer: A) A valid session can still be used to access unauthorized objects if authorization checks are missing
Explanation: IDOR can still occur if session-based authentication is implemented but authorization checks are weak or missing.
199. What is an effective way to detect IDOR vulnerabilities during security testing?
A) Manually modifying object references in API requests and checking for unauthorized access
B) Encrypting all request parameters
C) Running automated SQL injection tests
D) Checking for unpatched software versions
Answer: A) Manually modifying object references in API requests and checking for unauthorized access
Explanation: Manually modifying object IDs is a key technique in penetration testing for detecting IDOR vulnerabilities.
200. What is a potential impact of an IDOR vulnerability in a cloud storage service?
A) Attackers can modify file IDs to access or delete other users’ files
B) Users can upload their own files securely
C) The service automatically encrypts all stored files
D) The cloud provider will prevent all unauthorized access
Answer: A) Attackers can modify file IDs to access or delete other users’ files
Explanation: If file access control is weak, attackers can manipulate file IDs to gain unauthorized access or delete other users’ files.