[Mimedefang] DoS? and frozen machime

[David F. Skoll]

On Fri, 19 Jul 2002, Lavoie,Alain [CMC] wrote:

> 	The thing is, MIMEDefang was creating is directory
> (mdefang-3D381C96-0) in /var/spool/MIMEDefang. Every hanging e-mails
> has a directory and the number of directory was increasing very
> rapidly and the space decreasing at the same rate.  This was
> corrected easily with a script given previously on the list :) The
> other thing is that each hanging e-mails create a process
> mimedefang, and after to much mimedefang was crashing.

MIMEDefang does not create a new process for incoming mail unless you
aren't using the multiplexor.  However, the Sendmail milter library does
create a new thread for each incoming mail, and that could cause a problem.

You want to look at the Sendmail option "MaxDaemonChildren" which sets
a limit on the number of concurrent Sendmail processes.  This does *not*
prevent a DoS attack, but it can prevent the attack from crashing your
machine.

--
David.