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.

Elasticsearch Logstash 1.0.14 through 1.4.x before 1.4.2 allows remote attackers to execute arbitrary commands via a crafted event in (1) zabbix.rb or (2) nagios_nsca.rb in outputs/.