It was reported that Elasticsearch versions 1.3.0-1.3.7 and 1.4.0-1.4.2 have vulnerabilities in the Groovy scripting engine. The vulnerability allows an attacker to construct Groovy scripts that escape the sandbox and execute shell commands as the user running the Elasticsearch Java VM.

Upstream bug report: https://github.com/elasticsearch/elasticsearch/issues/9655

Upstream fixes: 1.3: https://github.com/elasticsearch/elasticsearch/commit/69735b0f4ab9ad7df4b82e8c917589b52cb9978c 1.4: https://github.com/elasticsearch/elasticsearch/commit/4e952b2d75de6ca4caf4b6743462714f3b60d07f 1.x: https://github.com/elasticsearch/elasticsearch/commit/716f0b24dc5414616e8dc0590dbfcfa0081be892

Mitigation: Users can address the vulnerability by setting script.groovy.sandbox.enabled to false in config/elasticsearch.yml and restarting the node.