Author: Evan Harris
Risk: Low
Affected Component: Grafana MCP Server

Introduction

As part of our ongoing security research into Model Context Protocol (MCP) servers, we identified a security gap in the Grafana MCP Server that enables unauthorized access to Grafana instances through unauthenticated network exposure.

Overview

The Grafana MCP Server, when launched with the -t sse flag, exposes an unauthenticated Server-Sent Events (SSE) interface that binds to 0.0.0.0:8000 by default when run via the Docker command provided in the MCP Server’s README. This configuration allows remote attackers with network access to interact with victims’ Grafana instances without authentication.

Technical Details

The Problem

When configured with SSE transport via Docker, the server:

  • Binds to 0.0.0.0:8000, making it accessible from any host on the network
  • Provides no authentication mechanism for the /sse endpoint
  • Trusts any connected client to execute privileged Grafana operations
  • Uses the victim’s GRAFANA_API_KEY to perform actions on their behalf

Vulnerable Configuration

Following the project README with SSE transport addition:

docker run --rm -p 8000:8000 \
  -e GRAFANA_URL \
  -e GRAFANA_API_KEY \
  mcp/grafana -debug -t sse

This exposes the endpoint at http://victim_ip:8000/sse to the entire network.

Attack Scenario

Victim Setup

A user following documentation:

  1. Downloads the Grafana MCP Server Docker image
  2. Configures environment variables GRAFANA_URL and GRAFANA_API_KEY for their Grafana instance
  3. Enables SSE transport by adding -t sse to the Docker command
  4. Unknowingly exposes http://their_ip:8000/sse to network-level attackers

Attacker Exploitation

An attacker with network access can:

  1. Discover the exposed endpoint at http://victim_ip:8000/sse
  2. Connect using MCP Inspector: npx @modelcontextprotocol/inspector sse --port 8000
  3. Execute unauthorized operations using available Grafana tools
  4. Manipulate dashboards by listing, creating, updating, or deleting them

Proof of Concept

Attack Demonstration

Using MCP Inspector, an attacker can connect to the exposed SSE endpoint and execute Grafana operations:

  • List teams to understand the organization structure
  • List dashboards to identify sensitive business intelligence
  • Create dashboards to inject malicious content
  • Update dashboards to modify existing visualizations
  • Access data sources and other privileged Grafana functionality

Impact Assessment

This attack vector enables:

Confidentiality Breach

  • Data source discovery exposing backend systems and configurations
  • Dashboard enumeration revealing sensitive business intelligence
  • User and team information leakage through MCP interface

Integrity Compromise

  • Malicious content injection potentially misleading users
  • Configuration tampering affecting visualization accuracy
  • Dashboard manipulation through creation, modification, or deletion

Availability Impact

  • Service disruption through dashboard deletion or corruption
  • Denial of service potential through system overload
  • Resource exhaustion via excessive tool requests

Risk Factors

  • Network Access Requirement: Attackers need network-level access to the victim
  • No Authentication: Any client can connect and execute privileged operations
  • Docker Default Binding: 0.0.0.0 exposure increases attack surface
  • Silent Operation: Attacks can occur without user awareness

For Users

  • Avoid using -t sse on shared or untrusted networks
  • Implement network-level restrictions using firewalls or VPNs
  • Use localhost binding by modifying Docker port mapping to 127.0.0.1:8000:8000
  • Monitor Grafana logs for unexpected API activity

Disclosure Timeline

  • 2024-05-22: Vulnerability discovered and reported to Grafana via Intigriti VDP
  • 2024-05-23: Grafana acknowledges receipt of report
  • 2024-05-23: Report marked as “Informative” by Grafana team
  • 2024-05-23: Grafana grants permission to publish findings publicly
  • 2025-09-02: Public disclosure and advisory publication

Conclusion

The unauthenticated SSE interface in Grafana MCP Server demonstrates the importance of secure defaults in development tools that bridge AI agents with enterprise systems.

While the network access requirement limits the attack surface, organizations deploying MCP servers should implement defense-in-depth strategies and maintain awareness of network exposure risks, especially in shared environments.

References