Inbound Connection to an Unsecure Elasticsearch Node

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Inbound Connection to an Unsecure Elasticsearch Node

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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:

  • auditbeat-*
  • filebeat-*
  • packetbeat-*
  • logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Network
  • Threat Detection
  • Initial Access
  • Host

Version: 7 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 8.4.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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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 guide

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Rule query

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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 mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 7 (8.4.0 release)
  • Formatting only
Version 5 (7.14.0 release)
  • Updated query, changed from:

    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
Version 4 (7.13.0 release)
  • Formatting only
Version 3 (7.12.0 release)
  • Formatting only
Version 2 (7.11.2 release)
  • Formatting only