Re: sendmail: open-relay

[Matthew Seaman]

Peter Ulrich Kruppa wrote:

Am Montag, den 04.01.2010, 13:45 +0000 schrieb Matthew Seaman:

Matthew Seaman wrote:

find the records in /var/mail/maillog to show abuse.net's server

connecting

Ooops.                /var/log/maillog

That would be those:
--------------------------------------------

cat maillog | grep "abuse.net"

Jan  4 12:26:46 pukruppa sm-mta[8964]: o04BQi0O008964:
from=<prvs=0613aad273=postmaster-ulrich=pukruppa....@abuse.net>,
size=333, class=0, nrcpts=1,
msgid=<20100104112454.38321.qm...@gal.iecc.com>, proto=ESMTP,
daemon=IPv4, relay=gal.iecc.com [208.31.42.53]
Jan  4 12:32:12 pukruppa sm-mta[10672]: o04BWBOA010672:
from=<spamt...@abuse.net>, size=909, class=0, nrcpts=1,
msgid=<rlytest-1262604620-41...@abuse.net>, proto=SMTP, daemon=IPv4,
relay=verify.abuse.net [208.31.42.77]
Jan  4 12:33:00 pukruppa spamd[1650]: spamd: checking message

BAYES_50,FH_DATE_PAST_20XX,RCVD_IN_DNSWL_HI

from=<spamt...@abuse.net>, size=909, class=0, nrcpts=1,
msgid=<rlytest-1262608007-71...@abuse.net>, proto=SMTP, daemon=IPv4,
relay=verify.abuse.net [208.31.42.77]
Jan  4 13:29:20 pukruppa spamd[1650]: spamd: checking message

AWL,BAYES_00,FH_DATE_PAST_20XX,RCVD_IN_DNSWL_HI

from=<spamt...@abuse.net>, size=909, class=0, nrcpts=1,
msgid=<rlytest-1262608435-75...@abuse.net>, proto=SMTP, daemon=IPv4,
relay=verify.abuse.net [208.31.42.77]
Jan  4 13:39:20 pukruppa spamd[1650]: spamd: checking message

AWL,BAYES_00,FH_DATE_PAST_20XX,RCVD_IN_DNSWL_HI

from=<spamt...@abuse.net>, size=906, class=0, nrcpts=1,
msgid=<rlytest-1262611567-9...@abuse.net>, proto=SMTP, daemon=IPv4,
relay=verify.abuse.net [208.31.42.77]
Jan  4 14:29:27 pukruppa spamd[1650]: spamd: checking message

AWL,BAYES_00,FH_DATE_PAST_20XX,RCVD_IN_DNSWL_HI


BTW. I have read somewhere, there might be problems with hostnames like
pukruppa.net, since they would allow to relay all mails from .net ?!?

<rlytest-1262604620-41...@abuse.net> for ulrich:1001 Jan 4 12:33:03 pukruppa spamd[1650]: spamd: result: . -4 - scantime=3.4,size=1231,user=ulrich,uid=1001,required_score=5.0,rhost=localhost,raddr=127.0.0.1,rport=28691,mid=<rlytest-1262604620-41...@abuse.net>,bayes=0.486826,autolearn=ham Jan 4 13:28:39 pukruppa sm-mta[56503]: o04CSb9P056503: <rlytest-1262608007-71...@abuse.net> for ulrich:1001 Jan 4 13:29:24 pukruppa spamd[1650]: spamd: result: . -6 - scantime=3.4,size=1231,user=ulrich,uid=1001,required_score=5.0,rhost=localhost,raddr=127.0.0.1,rport=21436,mid=<rlytest-1262608007-71...@abuse.net>,bayes=0.000000,autolearn=ham Jan 4 13:35:47 pukruppa sm-mta[58137]: o04CZkfq058137: <rlytest-1262608435-75...@abuse.net> for ulrich:1001 Jan 4 13:39:24 pukruppa spamd[1650]: spamd: result: . -6 - scantime=4.1,size=1231,user=ulrich,uid=1001,required_score=5.0,rhost=localhost,raddr=127.0.0.1,rport=24280,mid=<rlytest-1262608435-75...@abuse.net>,bayes=0.000000,autolearn=ham Jan 4 14:27:59 pukruppa sm-mta[87839]: o04DRvKd087839: <rlytest-1262611567-9...@abuse.net> for ulrich:1001 Jan 4 14:29:30 pukruppa spamd[1650]: spamd: result: . -6 - scantime=3.1,size=1227,user=ulrich,uid=1001,required_score=5.0,rhost=localhost,raddr=127.0.0.1,rport=27859,mid=<rlytest-1262611567-9...@abuse.net>,bayes=0.000000,autolearn=ham ----------------------------------------------------------

Something doesn't add up here -- the log shows the message being processed
by SpamAssassin, but there was no indication in the sendmail .mc file you
showed us of any integration with a spam filter.  I'd expect some sort of
milter configuration.

Unfortunately as well, the log line showing the delivery result is usually
one of the ones *following* the line showing the external MTA handing off the 
message to you.  Try grepping for the sendmail queue IDs:

  o04BQi0O008964
  o04BWBOA010672
  o04CSb9P056503
  o04CZkfq058137
  etc.


should be 5.x.y (ie. permanent failure) and a snotty message about 'relaying 
denied'.

        Cheers,

        Matthew


positives.

--
Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
                                                 Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey     Ramsgate
                                                 Kent, CT11 9PW

The lines that say 'dsn=<something>' are the important bits. If <something> is 2.0.0 (ie. successful delivery) then you've got a real problem. The result btw. you need to update your SpamAssassin rules -- you're triggering on the FH_DATE_PAST_20XX test all the time, which will give you some false

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