Please follow the below explained step to enable this setting in CloudForge.
If you view the menu bar at the top of your CloudForge UI Dashboard, you should see the 'Admin' pull-down menu and be able to navigate the SVN Global Settings page by clicking through :
Admin > Global Settings > Service Settings > Subversion > Global Settings > Allow anonymous access
There check mark the box that says 'Allow anonymous access'. However, this does means that all repositories in your domain would have to be public as well.