CVE-2017-14730
The init script in the Gentoo app-admin/logstash-bin package before 5.5.3 and 5.6.x before 5.6.1 has "chown -R" calls for user-writable directory trees, which allows local users to gain privileges by leveraging access to a $LS_USER account for creation of a hard link.
Source: CVE-2017-14730