Mailing List Archive

smap and qmail
farley@Manassas1.TDS-GN.LMCO.COM (Patrick Farley) asked:
>
>Does anyone have smap running with qmail here?
>

I don't think it's necessary. According to the TIS docs for smap,
it was created because "SMTP mail poses a threat to the system,
since mailers run with systems-level permissions..." and it is
intended to "insulate a notoriously buggy program which has been
implicated in many break-ins in the past."

The methods it accomplishes this are:

o Small program, easily verified as secure by reading source code,

o Runs as unprivileged user instead of root,

o Chroots to its spool directory, unable to write to files
anywhere else on the system.

The qmail smtp daemon does the first two, and instead of using
chroot(), it runs qmail-queue, another unprivileged program,
to put the message into the queue.

So running smap with qmail doesn't really gain you anything.

-Greg
--
Greg Andrews West Coast Online
Unix System Administrator 5800 Redwood Drive
gerg@wco.com Rohnert Park CA 94928
(yes, 'greg' backwards) 1-800-WCO-INTERNET
Re: smap and qmail [ In reply to ]
> The qmail smtp daemon does the first two, and instead of using
> chroot(), it runs qmail-queue, another unprivileged program,
> to put the message into the queue.

Sorry for the nitpick, but qmail-queue is a privileged program:
-rwsr-xr-x 1 qmailq qmail 12292 Dec 15 22:06 qmail-queue
^
It employs the least privilege principle and is therefore more secure
than anything running setuid root, howver.

olaf