Security Strategies for Elasticsearch: Network, OS, Server, and Access Controls

Elasticsearch servers, which power many search functions, suffered multiple large‑scale data leaks in early 2019, affecting millions of records from various organizations.

The 360 DBA team shares a series of security practices to help safeguard Elasticsearch deployments.

Security Strategy

Network Layer

External attacks typically come through the network, so a robust firewall (hardware or software) should be configured to block unwanted traffic. If no network protection exists, attackers can easily reach the service.

OS Layer

Public IPs act like ladders over a wall; if Elasticsearch runs in an internal network, unused public IPs should be removed to reduce exposure.

Server Layer

Run Elasticsearch under a non‑root user and set data directory ownership accordingly, preventing privileged escalation.

Port Replacement

Change the default HTTP port (9200) and transport port (9300) to obscure the service, similar to adding a hidden door to a vault.

User and Permission Authentication

Without authentication, Elasticsearch is like an unlocked safe. Although Elasticsearch lacks built‑in auth, the free open‑source plugin Search Guard provides robust access control.

Search Guard features include:

SSL/TLS encryption for both Transport and REST layers, configurable independently.

A complete user‑role‑permission model, with free‑tier controls down to index/type and host level.

Advanced Document‑level and Field‑level security, audit logging, and integration with LDAP/Kerberos available in the paid Enterprise license.

Dynamic permission updates via files stored in the searchguard index and applied with the sgadmin tool without restarting nodes.

Plugin‑based deployment; since Elasticsearch 5.x, Search Guard SSL is bundled, simplifying installation.

Search Guard also integrates smoothly with Logstash and Kibana, making it suitable for ELK stack users.

Conclusion

The shared strategies—ranging from network hardening to authentication—are simple yet often overlooked, and can prevent future maintenance pitfalls when deploying Elasticsearch securely.

Wishing everyone a productive start to their work!