> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flintai.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Insufficient authorization/access control

> Server doesn’t restrict tool usage based on authenticated identity or defined policies.

Server doesn’t restrict tool usage based on authenticated identity or defined policies.

## How to resolve

* **Implement access control mechanisms:** Implement role-based access control (RBAC) or attribute-based access control (ABAC) within the MCP server to enforce authorization policies for tool invocations. Define roles and permissions that map authenticated identities to allowed operations, ensuring the principle of least privilege. Add authorization checks before each tool execution to verify that the caller has the necessary permissions. Consider implementing OAuth 2.0 scopes or similar token-based authorization mechanisms to provide fine-grained access control.
* **Audit logs:** Maintain an audit log of all access control decisions and tool invocations for compliance and security monitoring.
* **Reviews permissions regularly:** Regularly review and update permission policies to ensure they align with current security requirements and organizational policies.

## Risk

**Governance/Compliance**

Insufficient authorization vulnerabilities violate multiple security standards:

* **NIST Cybersecurity Framework 2.0 (PR.AA):** Does not implement identity management and access control measures to ensure users can only perform actions within their authorized scope.
* **OWASP MCP Top 10 (MCP07:2025 - Insufficient Authentication & Authorization):** Allows authenticated entities to invoke privileged tools and access sensitive functionality beyond their authorization level.
* **OWASP Top 10 2025 (A01:2025 - Broken Access Control):** Fails to enforce user authorization to grant access to resources.

**Security**

Without proper authorization controls, any authenticated entity can invoke privileged tools and access sensitive data or functionality they should not have permission to use. This enables privilege escalation attacks where low-privilege users or compromised LLMs can perform administrative actions, access confidential information, modify critical data, or execute dangerous operations. The lack of authorization granularity means that authentication alone is insufficient to prevent unauthorized actions, potentially leading to data breaches, system compromise, and compliance violations.

## Explanation

This issue is raised when an MCP server does not properly restrict tool usage based on the authenticated identity of the caller or according to defined access control policies. Without proper authorization checks, any authenticated user or LLM may be able to invoke sensitive tools regardless of whether they should have permission to do so. This can result in privilege escalation, unauthorized data access, and other security violations.

## Specifications

**Trigger**

* MCP server scan detects that the server does not implement role-based access control (RBAC) or specific permission checks for tool invocations.

**Severity**

* HIGH

**Applies to**: MCP Server