By now, we’ve all seen this coming. With MongoDB falling victim to ransomware attacks, other NoSQL technologies like Elasticsearch were bound to follow. The alarming truth? Many Elasticsearch clusters are still open to the internet, vulnerable to attackers exploiting weak security practices, default configurations, and exposed ports.
This guide covers essential steps to protect your Elasticsearch cluster from becoming the next target.
TL;DR: Essential Security Measures
- Use X-Pack Security: If possible, implement Elastic’s built-in security features.
- Do Not Expose Your Cluster to the Internet: Keep your cluster isolated from public access.
- Avoid Default Configurations: Change default ports and settings to reduce predictability.
- Disable HTTP Access: If not required, disable HTTP access to limit attack vectors.
- Use a Firewall or Reverse Proxy: Implement security layers like Nginx, VPN, or firewalls (example Nginx config).
- Disable Scripts: Turn off scripting unless absolutely necessary.
- Regular Backups: Use tools like Curator to back up your data regularly.
The Ransomware Playbook
Ransomware attackers are targeting Elasticsearch clusters, wiping out data, and leaving ransom notes like this:
“Send 0.2 BTC (bitcoin) to this wallet xxxxxxxxxxxxxx234235xxxxxx343xxxx if you want to recover your database! Send your service IP to this email after payment: xxxxxxx@xxxxxxx.org.”
Their method is straightforward:
- Target: Internet-facing clusters with poor configurations.
- Exploit: Clusters with no authentication, default ports, and exposed HTTP.
- Action: Wipe the cluster clean and demand payment.
Why Are Clusters Vulnerable?
Many Elasticsearch admins overlook basic security practices, leaving clusters open to the internet without authentication or firewall protection. Even clusters with security measures are often left with weak passwords, exposed ports, and unnecessary HTTP enabled.
The lesson? Default settings are dangerous. Attackers are actively scanning for such vulnerabilities.
How to Protect Your Elasticsearch Cluster
1. Use Elastic’s X-Pack Security
X-Pack, Elastic’s security plugin, provides out-of-the-box protection with features like:
- User authentication and role-based access control (RBAC).
- Encrypted communication.
- Audit logging.
If you’re using Elastic Cloud, these protections are enabled by default.
2. Avoid Exposing Your Cluster to the Internet
Isolate your cluster from public access:
- Use private IPs or a Virtual Private Network (VPN).
- Block all inbound traffic except trusted sources.
3. Change Default Ports and Configurations
Avoid predictability by changing Elasticsearch’s default port (9200) and disabling unnecessary features like HTTP if they aren’t required.
4. Implement Firewalls and Reverse Proxies
Add security layers between your cluster and potential attackers:
- Use a reverse proxy like Nginx or Apache.
- Configure firewall rules to allow only trusted IPs.
5. Disable Scripting
Unless absolutely necessary, disable Elasticsearch’s scripting capabilities to minimize attack surfaces. You can disable scripts in the elasticsearch.yml configuration file:
script.allowed_types: none6. Regular Backups with Curator
Data loss is inevitable without backups. Use tools like Elasticsearch Curator to regularly back up your data. Store snapshots in a secure, offsite location.
Additional Resources
- Elastic’s Guide to Protecting Against Ransomware
- Securing Your Elasticsearch Cluster Properly by Itamar Syn-Hershko
Closing Thoughts
Elasticsearch ransomware attacks are a stark reminder of the importance of proactive security measures. Whether you’re hosting your cluster on Elastic Cloud or self-managing it, adopting the security best practices outlined here will safeguard your data from malicious actors.
Remember:
- Change default configurations.
- Isolate your cluster from the internet.
- Regularly back up your data.
If your Elasticsearch cluster is unprotected, the time to act is now—don’t wait until it’s too late.