PostgreSQL before 8.4.20, 9.0.x before 9.0.16, 9.1.x before 9.1.12, 9.2.x before 9.2.7, and 9.3.x before 9.3.3 does not properly enforce the ADMIN OPTION restriction, which allows remote authenticated members of a role to add or remove arbitrary users to that role by calling the SET ROLE command before the associated GRANT command.