Full Disclosure mailing list archives

Re: verizon vs m$


From: Christian Sciberras <uuf6429 () gmail com>
Date: Tue, 7 Dec 2010 23:03:16 +0100

See Marsh, there's this thing called keyboard and mouse which are trivially
a huge security threat to the user. Users shouldn't be allowed to use them.
The average user should be staring at the same MSN homepage all day long.

Then we should pay Microsoft (and really, all the ingenious security
researchers out there) that thought up the idea. Maybe even patent it or
something.










On Tue, Dec 7, 2010 at 9:51 PM, Marsh Ray <marsh () extendedsubset com> wrote:

On 12/07/2010 07:12 AM, Valdis.Kletnieks () vt edu wrote:
On Tue, 07 Dec 2010 07:16:34 EST, Larry Seltzer said:
2. some interpret it as a feature and some as a bug?

Does it have to be either?

It sounds to me as if this is a deliberate design decision, and
people are disagreeing over the severity of its implications.

Some people refer to that as a "feee-tchure" or "Broken As Designed".
It's technically not a bug, but it does violate the Principle of
Least Surprise.

I say it's a bug.

See there's this thing called "Protected Mode". Now I don't know about
you guys, but that name could lead someone like me to think that it was
supposed to give you some kind of protection. But whatever it is, it can
be bypassed by this new Son-of-Stuxnet APT 3.0 exploit technology called
a "socket".


http://windows.microsoft.com/en-us/windows-vista/products/features/communication
 Internet Explorer
Browse the web with Internet Explorer 7. Protected Mode provides
security and data protection for Windows users.

http://msdn.microsoft.com/en-us/library/bb250462%28VS.85%29.aspx
Understanding and Working in Protected Mode Internet Explorer Summary
In Windows Vista, Internet Explorer 7 runs in Protected Mode, which
helps protect users from attack by running the Internet Explorer
process with greatly restricted privileges.
Protected Mode is an important step forward in security for Internet
Explorer (IE); it helps protect users from attack by running an IE
process with greatly restricted privileges on Windows Vista. While
Protected Mode does not protect against all forms of attack, it
significantly reduces the ability of an attack to write, alter, or
destroy data on the user's machine or to install malicious code.

So if this thing allows any code running in "Protected Mode" to bridge
over to "not Protected mode" with just a local socket and other methods,
then what good is it? What then did "Protected Mode" ever protect you
from? Attackers who didn't know about local sockets or would never be
clever enough to figure it out?

Consider that Local Intranet Zone will usually do NTLMv2 authentication
without any user intervention. Even if he couldn't escape from
"Protected Mode", an attacker who can open listening sockets can
possibly grab NTLMv2 password hashes for offline cracking, or even
forward those authentications to get into lots of other devices which
will accept them, e.g. SSL VPNs.

This is just like UAC. Back when it came out, I thought UAC and the
elevation token scheme were the coolest new OS security feature since
W^X and ASLR. I gave props to Microsoft for enduring all the negativity
they got for UAC. But when I learned that they had exempted their own
executables from UAC with an "auto elevate" signature in the mainifest I
just couldn't believe it.

With trembling hands, I clicked on the microsoft.com product features
page and there it was: It was clearly promoting UAC and process
elevation as a security feature. A Microsoft product turned out not to
provide an effective security boundary after all. I was *shocked*.
On that day, my innocence was forever lost.

This is, IMHO, disingenuous of them to promote something as a feature
which enhances security and then say later "No of course it's not a
security boundary, whatever would make you think that?".

What possible definition of the term "security boundary" would _not_
encompass a facility for "running the Internet Explorer process with
greatly restricted privileges" such that it "significantly reduces the
ability of an attack to write, alter, or destroy data on the user's
machine or to install malicious code"?!

If process elevation is not a "security boundary", then what does it
elevate from, what does it elevate to, and what do you call the
difference between them?

I assume others have reported this by now, but last I checked a year or
so ago, some of these "auto elevate" processes in Vista were loading
DLLs by names obtained from registry values that were writable by
non-elevated tokens.

If you say something offers "protection" and people pay money to upgrade
to this security-as-a-feature, and this "protection" is trivially
bypassed, that's a security bug. You should fix it or give people their
money back. Don't then say "well we never actually said it was a
security boundary".

- Marsh

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

Current thread: