Unspecified vulnerability in Oracle MySQL Server 5.6.21 and earlier allows remote authenticated users to affect availability via unknown vectors related to Pluggable Auth.
https://security.gentoo.org/glsa/201504-05
https://exchange.xforce.ibmcloud.com/vulnerabilities/100190
http://www.securitytracker.com/id/1031581
http://www.securityfocus.com/bid/72229
http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.html