Onderwerp: Email marketing company gives out questionable security advice

Hi,

Last week, I received an unsolicited email message from Mobil Travel
Guide about their new online service. In the message, I was encouraged
to turn back on ActiveX and scripting in Outlook in order to view a
Flash movie embedded in the message. Needless to say, I thought this
was a terrible idea. Instead, I wrote the company who created the ad,
Digital Produce (http://www.digitalproduce.com), saying they were giving
out bad security advice and they should stop doing this sort of thing
in future mailings.

I got a reply from the company this week basically saying that they
agree with my concern, but not my solution. Instead they decided to put
a little security warning on their "real media fix" page. This fixer
page can be found here on their Web site:

http://www.digitalproduce.com/site_r...fs/outlookfix/

I think the warning message is pretty lame and misleading. Microsoft
released the Outlook Security Update a few years back because anti-virus
software wasn't stopping email worms. Turning back on ActiveX and
scripting only encourages the virus writers.

(As an aside, the Xbox division of Microsoft is also a customer of
Digital Produce. I wonder if any Xbox ads gave out this same bad
security advice?)

OTOH, it's not too hard too understand where Digital Produce is coming
from. According to a recent article in Internet News, only about 30% of
email users can view rich media email. This percentage is declining as
people upgrade Outlook and Outlook Express to newer versions with better
security features. It's pretty obvious that Flash-enabled email is a
dying market.

Along these same lines, images in HTML email messages will be the next
thing to go. The upcoming versions of Outlook and the AOL 9.0 email
reader will no longer show images in HTML email messages by default.
Hotmail offers this same feature as an option today. This feature is
intend to make email more kid-friendly by blocking porno pictures in
incoming spam messages. It also stops spammers for snooping on people
using Web bugs.

It will be interesting to see how email marketing companies and
spammers adapt to these technical changes in HTML email.

Richard M. Smith
http://www.ComputerBytesMan.com

I am continually amazed at the number of web sites which are unusable when
java and ActiveX are disabled. Generally, html geeks get paid to make cool
web sites (and email) which use all the local/interactive "make your machine
do things" features; most don't seem to be aware of (or care about) the
security implications. Try blocking active content at your firewall and see
how long it takes for clients to complain about not being able to use web
sites (even medical practice / insurance company web sites), not being able
to get emails/attachments, etc. Education efforts aside, this puts us in
the position of having to field complaints about "the damn firewall". Does
anyone else deal with this?

- stonewall

----- Original Message -----
From: "Richard M. Smith" <rms@computerbytesman.com>
To: "BUGTRAQ@SECURITYFOCUS. COM" <BUGTRAQ@SECURITYFOCUS.COM>
Sent: Wednesday, July 02, 2003 8:03 PM
Subject: Email marketing company gives out questionable security advice


> Hi,
>
> Last week, I received an unsolicited email message from Mobil Travel
> Guide about their new online service. In the message, I was encouraged
> to turn back on ActiveX and scripting in Outlook in order to view a
> Flash movie embedded in the message. Needless to say, I thought this
> was a terrible idea. Instead, I wrote the company who created the ad,
> Digital Produce (http://www.digitalproduce.com), saying they were giving
> out bad security advice and they should stop doing this sort of thing
> in future mailings.
>
> I got a reply from the company this week basically saying that they
> agree with my concern, but not my solution. Instead they decided to put
> a little security warning on their "real media fix" page. This fixer
> page can be found here on their Web site:
>
> http://www.digitalproduce.com/site_r...fs/outlookfix/
>
> I think the warning message is pretty lame and misleading. Microsoft
> released the Outlook Security Update a few years back because anti-virus
> software wasn't stopping email worms. Turning back on ActiveX and
> scripting only encourages the virus writers.
>
> (As an aside, the Xbox division of Microsoft is also a customer of
> Digital Produce. I wonder if any Xbox ads gave out this same bad
> security advice?)
>
> OTOH, it's not too hard too understand where Digital Produce is coming
> from. According to a recent article in Internet News, only about 30% of
> email users can view rich media email. This percentage is declining as
> people upgrade Outlook and Outlook Express to newer versions with better
> security features. It's pretty obvious that Flash-enabled email is a
> dying market.
>
> Along these same lines, images in HTML email messages will be the next
> thing to go. The upcoming versions of Outlook and the AOL 9.0 email
> reader will no longer show images in HTML email messages by default.
> Hotmail offers this same feature as an option today. This feature is
> intend to make email more kid-friendly by blocking porno pictures in
> incoming spam messages. It also stops spammers for snooping on people
> using Web bugs.
>
> It will be interesting to see how email marketing companies and
> spammers adapt to these technical changes in HTML email.
>
> Richard M. Smith
> http://www.ComputerBytesMan.com
>
>

Richard M. Smith writes:
[ mail readers disabling inline images ]
> It will be interesting to see how email marketing companies and
> spammers adapt to these technical changes in HTML email.

ASCII porn, perhaps? Especially if the sender can control the color, and
size, of text. I suppose those will be the next casualties in the war on
spam.

It's quite depressing that this is what people think of as ``security'':
patch maniacally; install a scanner that checks for yesterday's attacks;
don't view the pictures, don't drink the water, don't breathe the air.

I've been playing with a radically different system design (I'm thinking
of calling it ``UNIX'') where conceptually separate tasks are split into
separate processes. If you want to gunzip a stream of data, for example,
you run a gunzip program in its own chroot jail, under its own uid, with
no way to read any interesting data except through a predefined IPC hook
(I'm thinking of calling that a ``pipe'' on ``standard input'') and with
no way to touch anything except through another predefined IPC hook. The
only thing that an attacker can do by taking over this gunzip program is
generate arbitrary output data, which he could have done anyway. Typical
picture-generating programs can be isolated in the same way.

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago

P.S. It's hard for a portable chroot tool to cut off a program's network
access. Kernel designers should provide a disablenetwork() syscall, with
the disabling inherited by children. Other kernel changes would be nice,
but disablenetwork() is the only critical change.

On Friday 04 July 2003 13:05, stonewall wrote:
> Education efforts aside, this
> puts us in the position of having to field complaints about "the damn
> firewall". Does anyone else deal with this?

We do considerable filtering/blocking for some of our customers. We have
found that there is a significant reduction in complaints if the filter
returns a friendly error message to inform the user that things are going
according to plan rather then allowing an access attempt to fail silently.
YMMV
--
Ken Dyke
Chief Gadgeteer, Elegant Innovaions

On 4 Jul 2003, D. J. Bernstein wrote:

> Richard M. Smith writes:
>
> P.S. It's hard for a portable chroot tool to cut off a program's network
> access. Kernel designers should provide a disablenetwork() syscall, with
> the disabling inherited by children. Other kernel changes would be nice,
> but disablenetwork() is the only critical change.
>
Look at selinux. You can drop any privleges under selinux or Bull Dog
or you can uses Linux Socket Filtering is user space with kernel 2.4.18+
--

Enjoy,

Richard Rager

On 1057360640 seconds since the Beginning of the UNIX epoch
"D. J. Bernstein" wrote:
>

>P.S. It's hard for a portable chroot tool to cut off a program's network
>access. Kernel designers should provide a disablenetwork() syscall, with
>the disabling inherited by children. Other kernel changes would be nice,
>but disablenetwork() is the only critical change.

There are tools such as systrace:

http://www.citi.umich.edu/u/provos/systrace/

which comes standard in NetBSD and OpenBSD and has been ported to
various other UNIX platforms which can do what you want.

--
Roland Dowdeswell http://www.Imrryr.ORG/~elric/

I wrote:
: P.S. It's hard for a portable chroot tool to cut off a program's network
: access. Kernel designers should provide a disablenetwork() syscall, with
: the disabling inherited by children.

I've set up a web page http://cr.yp.to/unix/disablenetwork.html
discussing this and surveying the system-specific suggestions that
people have sent to me. Further contributions are welcome.

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago