Solaris

Maybe you can work along to the documentation:
Administering the FTP Server (Task Map) - System Administration Guide: Network Services

I think I solved the problem:
on /etc/passwd I have changed the shell of the user from bashto /bin/false
them I changed the group of the ftp user, them change the permissions of the landing directory

Perhaps. Why didn't you tell us this little detail when you told us "i created a user like this" in post #1? Obviously you did not "like this" but "like this and then a lot more".

If you want an anonymous yet secure ftp-service (what you did looks like this is what you are after) you might want to set up the ftpd (ftp server daemon) in a "chroot"ed environment. See man chroot for the details on this. This way you don't need a special user at all and you can still isolate the service from the rest of the system.

I hope this helps.

bakunin

perhaps I was misled by what this blogger: Solaris_blog: FTP user with restriction to home directory(CHROOT USER) when he says

These are different points: a "local zone" in Solaris is already a (sort-of) chroot-environment and you cannot chrootin a chroot-env. Therefore you need to do this from the global zone (=parent environment) instead.

I hope this helps.

bakunin