How to remediate – Metabase API Detection

1. Introduction

Metabase API Detection indicates a business intelligence application is running on a host within your network. Metabase allows users to explore and visualise data, which can be valuable for businesses but also introduces potential security risks if not properly secured. A successful exploit could lead to information disclosure.

2. Technical Explanation

The detection of the Metabase application itself isn’t a vulnerability, but indicates a service is present that may have vulnerabilities. Attackers can attempt to exploit known weaknesses in Metabase to gain unauthorised access to data or compromise the underlying system. Preconditions include network connectivity to the Metabase instance and valid credentials if authentication is required.

• Root cause: The presence of a potentially vulnerable application on the network.
• Exploit mechanism: An attacker could attempt to exploit known vulnerabilities in the Metabase API, such as SQL injection or unauthenticated access points. For example, an attacker might use crafted HTTP requests to bypass authentication and retrieve sensitive data from the database.
• Scope: All systems running Metabase are potentially affected. Specific versions may be more vulnerable than others; check the project’s GitHub repository for details.

3. Detection and Assessment

Confirming a system is running Metabase can be done with quick checks or thorough scanning methods.

• Quick checks: Use ps aux | grep metabase to check if the process is running. Check port 3000 for listening services using netstat -tulnp | grep :3000.
• Scanning: Nessus plugin ID 16789 can detect Metabase instances. OpenVAS also has relevant checks, but results may vary.
• Logs and evidence: Check web server access logs for requests to the Metabase application path (typically /). Look for unusual activity or error messages related to API calls.

ps aux | grep metabase

4. Solution / Remediation Steps

Fixing this issue involves securing or removing the Metabase instance. These steps assume you want to keep the application running; if not, removal is simpler.

4.1 Preparation

• Take a snapshot of the system before making changes. Stop the Metabase service using systemctl stop metabase (if applicable).
• Ensure you have access to the Metabase configuration file and database credentials. A roll back plan involves restoring from the snapshot or reinstalling the original version.
• A change window may be needed if stopping the service impacts users. Approval should come from the application owner.

4.2 Implementation

1. Step 1: Update Metabase to the latest stable version using the official documentation (https://www.metabase.com/docs).
2. Step 2: Review and harden the Metabase configuration file, ensuring strong authentication is enabled.
3. Step 3: Configure appropriate network access controls to restrict access to the Metabase instance.
4. Step 4: Restart the Metabase service using systemctl start metabase (if applicable).

4.3 Config or Code Example

Before

; Allow anonymous access
allow-anonymous-access: true

After

; Disable anonymous access
allow-anonymous-access: false

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent issues related to running applications like Metabase.

• Practice 1: Least privilege – limit the user account running Metabase to only the necessary permissions.
• Practice 2: Secure defaults – configure Metabase with strong passwords and disable unnecessary features.
• Practice 3: Patch cadence – Regularly update Metabase to address known vulnerabilities.

4.5 Automation (Optional)

If using configuration management, automate the hardening of the Metabase configuration file.

# Example Ansible task
- name: Harden Metabase config
  lineinfile:
    path: /etc/metabase/config.yml
    regexp: 'allow-anonymous-access:'
    line: 'allow-anonymous-access: false'

5. Verification / Validation

Confirm the fix worked by checking the Metabase version and verifying authentication is enforced.

• Post-fix check: Run metabase --version to confirm the updated version number.
• Re-test: Re-run the initial process check (ps aux | grep metabase) and ensure it’s running with the expected configuration.
• Smoke test: Log in to Metabase as a valid user and verify you can access data.
• Monitoring: Check application logs for failed login attempts or unusual API activity.

metabase --version

6. Preventive Measures and Monitoring

Preventing similar issues involves updating security baselines and adding checks to your CI/CD pipelines.

• Baselines: Update a security baseline or policy to require strong authentication for all business intelligence applications.
• Pipelines: Add SAST (Static Application Security Testing) tools to your CI pipeline to scan the Metabase code for vulnerabilities.
• Asset and patch process: Implement a regular patch review cycle for all installed software, including Metabase.

7. Risks, Side Effects, and Roll Back

Updating or configuring Metabase could cause temporary service disruption.

• Risk or side effect 1: Service downtime during the update process. Mitigation: Schedule updates during off-peak hours.
• Risk or side effect 2: Compatibility issues with existing database connections. Mitigation: Test changes in a non-production environment first.

8. References and Resources

• Vendor advisory or bulletin: https://www.metabase.com/docs
• NVD or CVE entry: Check the Metabase GitHub repository for known vulnerabilities (https://github.com/metabase/metabase).
• Product or platform documentation relevant to the fix: https://www.metabase.com/docs/administration/security/authentication