[BusyBox] Busybox 1.0.0-pre10 and sendmail

Tzafrir Cohen tzafrir at technion.ac.il
Mon May 10 18:18:07 UTC 2004

On Mon, May 10, 2004 at 01:54:32PM -0400, Michael Shearer wrote:
> Hi,
> Why Sendmail, good question.  Well, it's the defacto SMTP daemon
> isn't it? 

Not exactly. Postfix and exim (mostly postfix) are gainig popularity.

I believe almost all linux distros have switched from sendmail to
something else as the default MTA.

> I don't really need all it's features but 

What exactly do you need?
* send mail by smtp?
* receieve mail by smtp?
* local delivery?
* filtering of some sorts?

> apart from
> being a hassle to configure, it's stable and secure.  I'd welcome
> any other recommendations.  

IIRC we had at least about one remote root exploit via sendmail per year
in the recent years. But I'm not sure.

> Why should BB set permissions to '/'?  Because right now, that's the
> only way I could get Sendmail to work.  Or else it complained that I
> had a World Writeable directory and didn't even want to start.

So, whoever built the system should fix this.

But then again: who mounted the root filesystem?

> I've since figured out the problem.  It turns out that this is only
> an issue when mounting the root filesystem over NFS.  The directory
> where my rootfs was located was World Writeable...  That's why the /
> inherited those permissions.  Now, it's debatable whether or not mount
> -t nfs should have changed those back to a+rwx,u-w. (Erik, any comments?)

Didn't the kernel perform the mount?

Tzafrir Cohen                       +---------------------------+
http://www.technion.ac.il/~tzafrir/ |vim is a mutt's best friend|
mailto:tzafrir at technion.ac.il       +---------------------------+

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