With X-Pack installed, Kibana versions 5.0.0 and 5.0.1 were not properly authenticating requests to advanced settings and the short URL service, any authenticated user could make requests to those services regardless of their own permissions.

Logstash versions prior to 2.3.3, when using the Netflow Codec plugin, a remote attacker crafting malicious Netflow v5, Netflow v9 or IPFIX packets could perform a denial of service attack on the Logstash instance. The errors resulting from these crafted inputs are not handled by the codec and can cause the Logstash process to exit.

Prior to Logstash version 5.0.1, Elasticsearch Output plugin when updating connections after sniffing, would log to file HTTP basic auth credentials.

With X-Pack installed, Kibana versions before 5.3.1 have an open redirect vulnerability on the login page that would enable an attacker to craft a link that redirects to an arbitrary website.

Kibana version 5.4.0 was affected by a Cross Site Scripting (XSS) bug in the Time Series Visual Builder. This bug could allow an attacker to obtain sensitive information from Kibana users.

Starting in version 5.3.0, Kibana had a cross-site scripting (XSS) vulnerability in the Discover page that could allow an attacker to obtain sensitive information from or perform destructive actions on behalf of other Kibana users.

Elastic X-Pack Security versions prior to 5.4.1 and 5.3.3 did not always correctly apply Document Level Security to index aliases. This bug could allow a user with restricted permissions to view data they should not have access to when performing certain operations against an index alias.

Elastic X-Pack Security versions 5.0.0 to 5.4.0 contain a privilege escalation bug in the run_as functionality. This bug prevents transitioning into the specified user specified in a run_as request. If a role has been created using a template that contains the _user properties, the behavior of run_as will be incorrect. Additionally if the run_as user specified does not exist, the transition will not happen.