The User.offer_account_by_email WebService method in Bugzilla 2.x and 3.x before 3.4.13, 3.5.x and 3.6.x before 3.6.7, 3.7.x and 4.0.x before 4.0.3, and 4.1.x through 4.1.3, when createemailregexp is not empty, does not properly handle user_can_create_account settings, which allows remote attackers to create user accounts by leveraging a token contained in an e-mail message.