Quoting "Rice, Kevin" <krice@???>:
> I'm thinking
> there's probably a way to use spamassassin's -P option as part of the
> transport to bypass the problem of spamcheck being an exploitable shell
> script. If you have any suggestions along those lines, that would be
> great!
You could look at the transport_filter command, it probably does what you
want. Or if you want, I've put a copy of my version of the script at the
end of this email as it's not really big. I do believe this script is now
secure but this was done rapidly, I may have missed something. I'll check
it again sometime next week.
> I just need to take some time and read the Exim docs. I'll eventually
> understand it as well as sendmail ;)
This is always a good idea! :)
===== start of script =====
#!/usr/bin/perl
# This is an small wrapper script around Mail::SpamAssassin for the use
# with the exim MTA
# It is released under the Terms of GNU General Public License (GPL) so
# use at your own risk!
#
# Original by Andreas Gohr <a.gohr@???>
#
# Modified 2002-01-04 by Patrice Fournier <pfournier@???>
# to use a direct pipe instead of $mail->pipe which uses a shell
# and can thus be exploited.
use Mail::Audit;
use Mail::SpamAssassin;
$exim = '/usr/sbin/exim'; #Full path to exim
$params = '-oMr spam-scanned -i'; #Additional params no need to change
#This variable is not used presently
#see the push(@parms..) if you need
#to change the params.
$savespam = 1; #1/0 should spam be saved somewhere?
$spamfile = '/var/spool/spam'; #If you said 1 above - where to put
#that nasty spam? Be sure this mailbox
#is writable by the user who runs this
#script (e.g. mail)
$sendspamback = 1; #1/0 should spam be sent back to Exim?
#These are given as command line arguments by exim:
$sender = shift(@ARGV);
$sender = '<>' if $sender eq '';
@recpt = @ARGV;
####### Main script
###########################################################
$mail = Mail::Audit->new(); #Read Mail from STDIN
$mail->{noexit} = 1; #Do not exit after $mail->accept()
$spamtest = Mail::SpamAssassin->new();
$status = $spamtest->check ($mail);
#Add the X-Spam Headers:
$status->rewrite_mail ();
if ($status->is_spam ()) {
$mail->accept($spamfile) if ($savespam);
exit(0) if (!$sendspamback);
}
# Feed the message back to exim:
# Can't use $mail->pipe as it uses a shell and is thus insecure
# Also, $mail->pipe will save to the default mail file if the open fails.
#$mail->pipe("$exim $params -f $sender $recpt");
push(@parms, "-oMr");
push(@parms, "spam-scanned");
push(@parms, "-i");
push(@parms, "-f");
push(@parms, "$sender");
push(@parms, @recpt);
open (PIPE, "|-") || exec($exim, @parms);
$mail->{obj}->print(\*PIPE);
close(PIPE);
# Send back Exim's return code
exit $? >> 8;
====== end of script ======
--
Patrice Fournier
pfournier@???
