ftpd don't record login in utmpx

[Lowell Gilbert]

Slawa Olhovchenkov <slw at zxy.spb.ru> writes:

> On Mon, Mar 30, 2015 at 08:08:49PM -0400, Lowell Gilbert wrote:
>
>> Slawa Olhovchenkov <slw at zxy.spb.ru> writes:
>> 
>> > ftpd from FreeBSD-10 and up don't record ftp logins to utmpx database
>> > (for case of chrooted login).
>> > This is lack security information.
>> > I found this is done by r202209 and r202604.
>> > I can't understand reason of this.
>> > Can somebody explain?
>> 
>> Having a jail log into the base system is a security issue in the
>> making. Can't you do this in a safer way by doing remote logging to the
>> base system rather than having the jail hold on to a file handle that
>> belongs outside the jail?
>
> Jail? Why I you talk about jail?

Because the principle is the same for any method of imprisoning a
process inside a particular file tree, whether it be chroot(8) or
jail(8) or a virtualized machine. The principle is: don't give the
imprisoned process access to any resources outside of its prison.

>> It's certainly possible to maintain these kinds of capabilities, but
>> you would have to convince code reviewers that the same results can't be
>> achieved some other way that's easier to secure.
>
> Can you explain some more?
> A im lost point.

You can always try to limit the ways that direct access outside the
chroot (et. al.) can be used (or abused). However, it is much easier to
make sure that there are no ways to break out of the chroot if the
direct access does not exist in the first place.