Elasticsearch » Logstash : Security Vulnerabilities, CVEs,

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.

Logstash 1.4.x before 1.4.5 and 1.5.x before 1.5.4 with Lumberjack output or the Logstash forwarder does not validate SSL/TLS certificates from the Logstash server, which might allow attackers to obtain sensitive information via a man-in-the-middle attack.

Logstash 1.5.x before 1.5.3 and 1.4.x before 1.4.4 allows remote attackers to read communications between Logstash Forwarder agent and Logstash server.