Joomla! 2.5.x before 2.5.4 does not properly check permissions, which allows attackers to obtain sensitive "administrative back end" information via unknown attack vectors. NOTE: this might be a duplicate of CVE-2012-1599.
http://www.openwall.com/lists/oss-security/2012/04/03/5
http://www.openwall.com/lists/oss-security/2012/04/03/3
http://secunia.com/advisories/48683
http://developer.joomla.org/security/news/398-20120307-core-information-disclosure.html