How to remediate – Magento Mass Importer < 0.7.24 Remote Authentication Bypass

1. Introduction

2. Technical Explanation

The vulnerability occurs because Magento Mass Importer does not properly manage database connections. An attacker can exhaust the connection pool, forcing the application to accept new connections without authentication checks. CVE-2020-5777 describes this issue. A realistic example is an attacker repeatedly initiating import processes until all database connections are used, then accessing the admin interface directly.

• Root cause: Insufficient connection management in Magento Mass Importer allows for exhaustion of available database connections.
• Exploit mechanism: An attacker floods the system with requests to initiate imports, consuming all database connections. Once exhausted, they can access the administration panel without authentication.
• Scope: Affected versions are Magento Mass Importer prior to 0.7.24.

3. Detection and Assessment

To confirm vulnerability, check the installed version of Magmi. Thorough assessment involves monitoring database connection usage during import processes.

• Quick checks: Check the Magmi version using the application interface or by examining the installation directory.
• Scanning: Nessus plugin ID 134698 can detect this vulnerability, but results should be verified manually.
• Logs and evidence: Examine web server logs for repeated import requests originating from a single source IP address. Look for errors related to database connection failures.

# No specific command available - check Magmi interface or installation directory

4. Solution / Remediation Steps

The following steps detail how to fix the issue. Prioritize disabling or removing the software as it has other known issues.

4.1 Preparation

• Ensure you have access to the Magento file system and a method for restoring backups. A roll back plan is to restore from backup.
• A change window may be required depending on your environment. Approval from security or IT operations may be needed.

4.2 Implementation

1. Step 1: Disable the Magento Mass Importer extension through the Magento admin interface (System > Configuration > Advanced > Developer > Magento Mass Importer).
2. Step 2: Remove the Magmi files from your server’s file system. The default location is typically /app/code/community/dweeves/magmi.

4.3 Config or Code Example

Before

# Magmi extension enabled in Magento configuration

After

# Magmi extension disabled in Magento configuration and files removed from file system.

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this issue. Least privilege reduces the impact of exploitation, while input validation prevents malicious data from being processed. A patch cadence ensures timely updates for known vulnerabilities.

• Practice 1: Implement least privilege principles to limit access to sensitive resources and reduce the potential damage caused by a compromised account.
• Practice 2: Regularly update all software components, including third-party extensions like Magento Mass Importer, to address known security vulnerabilities.

4.5 Automation (Optional)

# No automation script provided due to complexity of Magento environment. Manual removal is recommended.

5. Verification / Validation

• Post-fix check: Verify through the Magento admin interface (System > Configuration > Advanced > Developer) that the Magento Mass Importer is disabled.
• Re-test: Attempt to access the Magmi import interface; it should no longer be accessible.
• Smoke test: Confirm basic product browsing and checkout functionality are still working as expected.

# No specific command - check Magento admin interface

6. Preventive Measures and Monitoring

Update security baselines to include the latest software versions. Implement checks in CI/CD pipelines to prevent vulnerable components from being deployed. Establish a regular patch review cycle for all third-party extensions.

• Baselines: Update your Magento security baseline to require the latest version of Mass Importer or recommend its removal.
• Pipelines: Integrate SCA (Software Composition Analysis) tools into your CI/CD pipeline to identify and block vulnerable components like outdated versions of Magmi.
• Asset and patch process: Implement a regular review cycle for all third-party extensions, ensuring they are updated promptly or removed if no longer needed.

7. Risks, Side Effects, and Roll Back

• Risk or side effect 1: Disabling Magmi will break automated imports that rely on it.
• Risk or side effect 2: Removing Magmi may require manual reconfiguration of other extensions if they depend on its functionality.
• Roll back: Step 1: Re-enable the Magento Mass Importer extension through the admin interface. Step 2: Restore the original Magmi files from backup.

8. References and Resources

• Vendor advisory or bulletin: https://github.com/dweeves/magmi-git/
• NVD or CVE entry: CVE-2020-5777
• Product or platform documentation relevant to the fix: No specific documentation available.