elasticsearch -- remote OS command execution via Groovy scripting engine

Elastic reports:

Vulnerability Summary: Elasticsearch versions 1.3.0-1.3.7 and
1.4.0-1.4.2 have vulnerabilities in the Groovy scripting engine that
were introduced in 1.3.0. 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.
Remediation Summary: Users should upgrade to 1.3.8 or 1.4.3. Users
that do not want to upgrade can address the vulnerability by setting
script.groovy.sandbox.enabled to false in elasticsearch.yml and
restarting the node.