[Raw Msg Headers][Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Bad HELO strings

While we talk about incorrect `rcvdfrom' headers, I did an experiment:
telnetted to 25 port and entered deliberately bad HELO parameter:

Connected to chronos.sovam.com.
Escape character is '^]'.
220 chronos ZMailer Server 2.99.50-s5 #8 ESMTP+IDENT (nulltrans) ready at Wed,
3 Jun 1998 20:00:45 +0400
helo naster(X"
250 chronos expected "HELO ariel"
mail from:<crosser@online.ru>
250 2.1.0 Sender syntax Ok
rcpt to:<crosser@chronos.sovam.com>
250 2.1.5 Recipient address syntax Ok
354 Start mail input; end with <CRLF>.<CRLF>
Subject: x

250 2.6.0 S.pRLBZ928657 message accepted
221 2.0.0 chronos Out

Resulting message was rejected at the router stage (?) as having incorrect
header.  Seems that escaping of special characters where not correct.
Not a big deal: the case is really pathalogical, and resulting behavior
is not totally unacceptable (at least it did not crash :), but still...

Non-delivery report attached.


The following message arrived with illegal envelope data, typically a
mangled address that doesn't obey the RFC822/976 protocol specification.
If you do not recognize the source of the bad header, perhaps you should
contact a Postmaster at your site and ask why your mail was rejected.

Your message is being returned unprocessed.

The following annotated envelope headers illustrate the error(s):

Error in "rcvdfrom" envelope address:

	ariel([]:14657 "helo naster(X\"" ident: "crosser"))
	     ^-missing closing ')' in token

The entire original message file follows.

rcvdfrom ariel ([]:14657 "helo naster(X\"" ident: "crosser")
with SMTP
identinfo crosser
from <crosser@online.ru>
todsn ORCPT=rfc822;crosser@chronos.sovam.com
to <crosser@chronos.sovam.com>
Subject: x