We do not allow scripts to run under 777 for reasons of security. Executable scripts should run under 711 or 755, and PHP scripts should have permissions 644.
Simply go to SGIS > Check Site Permissions, and click the link to start a scan. Do note that if there are a lot of files to scan, this could take several minutes. Any files with the correct permissions aren't shown, and any that have potentially unsafe permissions are listed with a drop-down to let you select the correct permissions.