Session fixation vulnerability in Drupal 4.5.x before 4.5.8 and 4.6.x before 4.5.8 allows remote attackers to gain privileges by tricking a user to click on a URL that fixes the session identifier.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25205
http://www.securityfocus.com/bid/17104
http://www.securityfocus.com/archive/1/427589/100/0/threaded
http://www.debian.org/security/2006/dsa-1007
http://securityreason.com/securityalert/580
http://secunia.com/advisories/19257