The default for sun is to set "nobody"s home directory to "/". Even when not sharing "[homes]" we can access "\\servername\NOBODY" and until the home directory for nobody is altered, the entire filesystem is visible. There is no share in the smb.conf named "nobody" or anything even close to it.
Can you post your smb.conf file? Do you have the 'map to guest' parameter set? I've tried to reproduce this with a minimal smb.conf file but can't access a share called NOBODY (fails with "tree connect failed: NT_STATUS_BAD_NETWORK_NAME").
Created attachment 171 [details] smb.conf file from system exhibiting behavior
The supplied smb.conf includes the [homes] share, so I presume this one is user error. This is a documented effect of the [homes] share, and the reason for the 'valid users = %S' option. Possibly this should be a default.
database cleanup