Drupal 4.5.0 through 4.5.5 and 4.6.0 through 4.6.3, when running on PHP5, does not correctly enforce user privileges, which allows remote attackers to bypass the "access user profiles" permission.
http://www.vupen.com/english/advisories/2005/2684
http://www.securityfocus.com/bid/15674
http://www.securityfocus.com/archive/1/418336/100/0/threaded
http://www.debian.org/security/2006/dsa-958
http://secunia.com/advisories/18630
http://secunia.com/advisories/17824