A permission issue was found in Elasticsearch versions before 5.6.15 and 6.6.1 when Field Level Security and Document Level Security are disabled and the _aliases, _shrink, or _split endpoints are used . If the elasticsearch.yml file has xpack.security.dls_fls.enabled set to false, certain permission checks are skipped when users perform one of the actions mentioned above, to make existing data available under a new index/alias name. This could result in an attacker gaining additional permissions against a restricted index.
Elasticsearch before 1.6.1 allows remote attackers to execute arbitrary code via unspecified vectors involving the transport protocol. NOTE: ZDI appears to claim that CVE-2015-3253 and CVE-2015-5377 are the same vulnerability
The Groovy scripting engine in Elasticsearch before 1.3.8 and 1.4.x before 1.4.3 allows remote attackers to bypass the sandbox protection mechanism and execute arbitrary shell commands via a crafted script.