Beginning with sudo version 1.7.0 it has been possible to grant permission to run a command using a specified group via sudo -g option (run as group). A flaw exists in the logic that matches Runas groups in the sudoers file when the -u option is also specified (run as user). This flaw results in a positive match for the user specified via -u so long as the group specified via -g is allowed by the sudoers file.
