IDOR (Insecure Direct Object Reference)
Insecure Direct Object Reference (IDOR) is a security vulnerability where an attacker can access or modify unauthorized data by manipulating input values, such as object identifiers in URLs or API requests. This flaw occurs when an application fails to enforce proper authorization checks, allowing direct access to restricted resources. IDOR can lead to data breaches, unauthorized modifications, and privilege escalation, making it a critical issue in web application security.
Scenario: Accessing Another User’s Profile:
• A website uses the following URL to display a user’s profile: https://example.com/profile?user_id=123
• Note: If the application does not properly validate access permissions, an attacker could change user_id=123 to user_id=124 and access another user’s profile.
How to Prevent IDOR Vulnerabilities:
1. Implement Proper Access Controls: Always verify that the requesting user has permission to access the requested resource.
2. Use Indirect References: Instead of exposing raw database IDs, use random or hashed identifiers (e.g.,UUIDs).
3.Server-Side Authorization Checks: Ensure that access control checks occur on the server, not just in the front end.
4. Least Privilege Principle: Limit users’ access to only what is necessary for their role.
5. Logging and Monitoring: Track access patterns to detect and respond to unauthorized access attempts.