Re: [Full-disclosure] Microsoft Help Files (.CHM): 'Locked File' Feature Bypass

["Thor (Hammer of God)" <Thor@xxxxxxxxxxxxxxx>]

Glad to hear it - my "preface settings" aren't  working right so pardon the top 
post.

I'm glad you replied with that info - that's good info... I can leverage the 
same thing in RDP sessions then (or it seems like).  I didn't get the full 
implications from the post as you noted.

RE the MSFT bit, that's why I asked... it wasn't clear what you were saying.  
It didn't have the typical "sarcasm" feel, but it was kind of outside of the 
sentence structure so it seemed like you were trying to make different point.  
The "AU" references were just in regard to the current buzz about AU requiring 
AV to connect to the internet, not anything about you :)  I know better than to 
bring up the "Australia" vs "New Zealand" bit.   Speaking of which, was there 
an "Old Zealand?" ;)
t

From: Paul Craig [mailto:paul.craig@xxxxxxxxxxxxxxxxxxxxxxx]
Sent: Wednesday, June 23, 2010 1:03 PM
To: Thor (Hammer of God); full-disclosure@xxxxxxxxxxxxxxxxx
Subject: Re: Microsoft Help Files (.CHM): 'Locked File' Feature Bypass

Hey Thor, everything is well mate.

Firstly I think you may have missed the context of this bug, which was not 
apparent from my first post.
I spend a lot of time working on the security of internet Kiosks, Citrix 
terminals and other thin-clients.
In these situations, users are often blocked from downloading file types from 
remote sites, however CHM files are typically not blocked.
I had been playing with using a malicious help file for a while, but found the 
"blocked" feature essentially stopped me from launching anything.

When this trick is combined into the mix, shells appear on many kiosk platforms.
Yes you have to Agree to the dialog box, but when you're the one on the 
Kiosk/Citrix this is hardly a problem.
This is not a typical attack vector, and likely one you didn't think of, but I 
didn't want to get into that in my first post and simply detail an interesting 
'trick' I found.

As for Microsoft's response.
It was exactly as I expected, as simple as that, this is a low severity issue 
that does not warrant an immediate "stop the press" fix.
Why does everyone want to read sarcasm and back-handedness in every post ?

I also appreciate that you appear to know geography and mention Australia 
several times in your post, great one, but I am from New Zealand.
You might want to look it up on Gmaps some time, it's a separate country
How's the weather in Mexico anyway?
Paul

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