Jenkins Security Advisory 2014-02-14 notes: ""Jenkins' own user database" was revealing the presence/absence of users when login attempts fail." Upstream fix: https://github.com/jenkinsci/jenkins/commit/fbf96734470caba9364f04e0b77b0bae7293a1ec References: https://wiki.jenkins-ci.org/display/SECURITY/Jenkins+Security+Advisory+2014-02-14
This issue has been addressed in the following products: Red Hat OpenShift Enterprise 2.1 Via RHBA-2014:1630 https://rhn.redhat.com/errata/RHBA-2014-1630.html