The CallerIdentityLoginModule in JBoss Enterprise Application Platform (EAP) before 5.2.0, Web Platform (EWP) before 5.2.0, BRMS Platform before 5.3.1, and SOA Platform before 5.3.1 allows remote attackers to gain privileges of the previous user via a null password, which causes the previous user's password to be used.
https://exchange.xforce.ibmcloud.com/vulnerabilities/81512
https://bugzilla.redhat.com/show_bug.cgi?id=836451
http://www.securityfocus.com/bid/57547
http://securitytracker.com/id?1028042
http://secunia.com/advisories/52054
http://secunia.com/advisories/51984
http://rhn.redhat.com/errata/RHSA-2013-0533.html
http://rhn.redhat.com/errata/RHSA-2013-0221.html
http://rhn.redhat.com/errata/RHSA-2013-0198.html
http://rhn.redhat.com/errata/RHSA-2013-0197.html
http://rhn.redhat.com/errata/RHSA-2013-0196.html
http://rhn.redhat.com/errata/RHSA-2013-0195.html
http://rhn.redhat.com/errata/RHSA-2013-0194.html
http://rhn.redhat.com/errata/RHSA-2013-0193.html