In Grafana 2.x through 6.x before 6.3.4, parts of the HTTP API allow unauthenticated use. This makes it possible to run a denial of service attack against the server running Grafana.
{ "binaries": [ { "binary_name": "grafana", "binary_version": "2.6.0+dfsg-1" }, { "binary_name": "grafana-data", "binary_version": "2.6.0+dfsg-1" } ] }