Inbound Connection to an Unsecure Elasticsearch Nodeedit

Identifies Elasticsearch nodes that do not have Transport Layer Security (TLS), and/or lack authentication, and are accepting inbound network connections over the default Elasticsearch port.

Rule type: query

Rule indices:

  • packetbeat-*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-6m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Network
  • Threat Detection
  • Initial Access

Version: 1

Added (Elastic Stack release): 7.10.0

Rule authors: Elastic

Rule license: Elastic License

Potential false positivesedit

If you have front-facing proxies that provide authentication and TLS, this rule would need to be tuned to eliminate the source IP address of your reverse-proxy.

Investigation guideedit

This rule requires the addition of port 9200 and send_all_headers to the HTTP protocol configuration in packetbeat.yml. See the References section for additional configuration documentation.

Rule queryedit

event.category:network_traffic AND network.protocol:http AND status:OK
AND destination.port:9200 AND network.direction:inbound AND NOT
http.response.headers.content-type:"image/x-icon" AND NOT
_exists_:http.request.headers.authorization

Threat mappingedit

Framework: MITRE ATT&CKTM