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Re: [hylafax-users] Bug? in xferfaxlog!!!

Sa told earlier am I working out a likewise mechanism for our system. We don't
provide a 100% fax service because the the hazards/security risks as mentioned by
Lee. In stead I made it possible to send a fax via a form. Fill out the text in
your browser, push the send button, and of she goes...

Each fax destionation is represented by a mail address. This mail address is
forwarded to a fax number in a for the user unknown format. ie 12345678@whatever.
The fax to mail module trims this to 12345678.

To retrieve a list for this user could be done by grep 123456789 xferfaxlog >
log.txt. From here you can do whatever you want. Put it in a script, do a
text2html,... the sky is the limit :-)

Hope this tip is usefull.

Lee Howard wrote:

> At 12:39 PM 3/30/01 +0600, J.K.D.Ruwan Jayanetti wrote:
> >Hi,
> >
> >We're developing a billing system and web based access system for HylaFax.
> >We found out following problem in xferfaxlog.
> >
> >In this, the "sender" entry contains senders e-mail address. But not the
> >authenticated user name or id. So if someone send a fax putting some other
> >e-mail address as the notification e-mail, this e-mail address comes to
> >"sender" field. This is allowed when sending fax form a client through
> >hylafax protocol. At this situation there is a fax going out but the sender
> >is unidentifiable by the billing system as this log entry does not contain
> >authenticated user name or id. I think this is a BUG! and this field should
> >filled with user name or the user id. Or a new field should be added.
> You can't use the "sender" field as a reliable or secure submitter
> identification anyway, regardless of this being submitted by e-mail/faxmail
> or this being submitted by direct HylaFAX client communication.  Because
> you can spoof that "sender" field as much as you like... go ahead and play
> around with it more, and you'll see this.  "Sender" is merely whatever is
> in the sendfax -f option, for example, which is an entirely unrestricted
> field.
> If there is a problem, it is in your attempted use of the "sender" field as
> a secure method of identification.  Someone could log in using their own
> password and then use someone else's address in sendfax's -f field.
> Furthermore, you're mistaken if you believe that HylaFAX's faxmail is
> really in any way a secure method of fax submission.  Spoofing an e-mail
> address, or even an IP number is among the easiest tricks.
> Don't get me wrong, I think that the password-verification used by client
> applications like a remote sendfax, Cypheus, or WHFC is secure enough for
> most environments, but implementing faxmail is dangerous (I don't use
> faxmail, so maybe I'm off-base here) because you are required to add an
> e-mail address to etc/hosts.hfaxd and e-mail addresses can be easily spoofed.
> It's relatively easy to only allow certain people to use your fax service,
> but as for providing a means to securely log which faxusers sent which
> faxes, I'm not sure exactly how it can be done.  You need a logging
> mechanism that corresponds jobs with the faxuser that correlating with the
> faxpassword that was supplied.  I don't think HylaFAX has that feature yet,
> from what I can tell, it doesn't even log the logins into syslog.
> Bug?  Nah, it's simply a missing feature (or missing field as you noted),
> and a design weakness in the case of faxmail.
> Lee.
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Kind Regards,

Aasterud WebCom
Harry M. Aasterud      Tel.: +47 / 74 16 11 42
Utvik                  Faks: +47 / 74 16 11 43
NO-7730 Beitstad       http://www.aasterudweb.com
Norge - Norway

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