The Admin UI in Apache Ranger before 0.5.1 does not properly handle authentication requests that lack a password, which allows remote attackers to bypass authentication by leveraging knowledge of a valid username.Referenceshttp://www.securityfocus.com/bid/82871https://mail-archives.apache.org/mod_mbox/ranger-dev/201602.mbox/%3CD2D9A4C5.114ECA%25vel%40apache.org%3Ehttps://issues.apache.org/jira/browse/RANGER-835https://cwiki.apache.org/confluence/display/RANGER/Vulnerabilities+found+in+Ranger
