logstash -- password disclosure vulnerability

Logstash developers report:

Passwords Printed in Log Files under Some Conditions

It was discovered that, in Logstash 2.1.0+, log messages generated by a stalled pipeline during shutdown will print plaintext contents of password fields. While investigating this issue we also discovered that debug logging has included this data for quite some time. Our latest releases fix both leaks. You will want to scrub old log files if this is of particular concern to you. This was fixed in issue #4965

[source]