[New Rule] Detecting Unsecure Elasticsearch Nodes (#109)

rules/network/initial_access_unsecure_elasticsearch_node.toml

@@ -0,0 +1,50 @@
+[metadata]
+creation_date = "2020/08/11"
+ecs_version = ["1.6.0"]
+maturity = "production"
+updated_date = "2020/08/11"
+
+[rule]
+author = ["Elastic"]
+description = """
+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.
+"""
+false_positives = [
+    """
+    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.
+    """,
+]
+index = ["packetbeat-*"]
+language = "lucene"
+license = "Elastic License"
+name = "Inbound Connection to an Unsecure Elasticsearch Node"
+note = "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."
+references = [
+    "https://www.elastic.co/guide/en/elasticsearch/reference/current/configuring-security.html",
+    "https://www.elastic.co/guide/en/beats/packetbeat/current/packetbeat-http-options.html#_send_all_headers",
+]
+risk_score = 47
+rule_id = "31295df3-277b-4c56-a1fb-84e31b4222a9"
+severity = "medium"
+tags = ["Elastic", "Network"]
+type = "query"
+
+query = '''
+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
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1190"
+name = "Exploit Public-Facing Application"
+reference = "https://attack.mitre.org/techniques/T1190/"
+
+
+[rule.threat.tactic]
+id = "TA0001"
+name = "Initial Access"
+reference = "https://attack.mitre.org/tactics/TA0001/"