Full Disclosure mailing list archives

Re: Compromising pictures of Microsoft Internet Explorer!


From: tuytumadre () att net
Date: Sat, 16 Jul 2005 19:43:32 +0000

I do not meen to flame you, but you are an irresponsible disgrace to the hacking community. Do you not care about the 
customer? You never publicly disclose details to a vulnerability of this magnitude. This is an image vulnerability, for 
crying out loud. What's the first thing they tell you to do when most vulnerability details are released? Disable 
active scripting. That doesn't work here. What are the innocent, ignorant computer users going to do? Disable images? I 
think not. You should be ashamed.

I firmly believe that you are decieving us when you say you had a hard time with secure () microsoft com; in fact, I 
don't even think that you have ever once in your life reported a vulnerability to them responsibly. Otherwise, you 
would not have such harsh feelings about them. If the evil of the stereotypical Microsoft machine exists anywhere on 
the campus in Redmond, it will not be found in the building of MSRC, which is where your secure () microsoft com emails 
are directed.

Come on man. I know you have talent. You are a good researcher of computer security. But if your talent is going to be 
wasted like this, you are nothing more to us than a script kiddie.

Regards,
Paul
Greyhats Security
http://greyhatsecurity.org

-------------- Original message from Michal Zalewski <lcamtuf () dione ids pl>: -------------- 


Synopsis: 
--------- 

Well, not really. Instead, at the risk of boring you to death, I'd like 
to report on a casual 30-minute experiment I've conducted of recent. 
This experiment resulted in identifying a potential remote code 
execution path in Microsoft Internet Explorer, plus some other bugs, and 
should be a good starting point for further testing of other browsers or 
similar programs. 

Discussion: 
----------- 

You might remember the 'mangleme' affair, where various browsers were 
subjected by yours truly to a trivially constructed malformed HTML 
crash-course - all that in order to find exploitable input handling flaws. 
Back then, MSIE performed admirably compared to other browsers (although 
did not escape some embarassment when ned@felinemenace found the 
infamous IFRAME bug that way): 

http://lcamtuf.coredump.cx/mangleme/gallery/ 

Of recent, I decided to try something completely different and radically 
new, without having to do any actual work. I used the same META REFRESH 
auto-test framework to check for image decompression and parsing flaws 
(JPEG, GIF, PNG), as opposed to making fun of HTML renderers. 

I used a simple index.cgi script (attached, though hardly noteworthy) to 
dynamically generate a page that references ten just as dynamically 
created images. These images were prepared by running a test set of 
pictures (some regular ones, and several pathological cases created with 
ImageMagick) through a slightly modified version of my old afx utility. 

Surprisingly, it is MSIE and its proprietary JPEG decoder (apparently 
not shared with other Windows components?) that performed embarassingly 
poor this time. Results below. 

Vulnerability examples: 
----------------------- 

NOTE #1: As with mangleme, this list of problems is most certainly NOT 
exhaustive, and performing longer tests or improving the technique 
would most likely result in additional findings. 

Several MSIE crash sample files from that 30-minute run are available 
at: 

http://lcamtuf.coredump.cx/crash/ 

Note that these may produce different results depending on program 
versions, plugins and configuration. Tested with WinXP Pro PL 
2600.xpsp2.050301-1526 SP1, MSIE PL 6.0.2800.1106, up-to-date. 

mov_fencepost.jpg - on most platforms, causes a crash due to mov 
destination fencepost error after going past allocated memory, or 
after accessing a bogus address such as 0x27272727. The destination 
address appears to be controllable (i.e. changing the file or 
displaying other data before or along with this image alters it). 
My bets are that this is exploitable for remote execution. 

cmp_fencepost.jpg - here, causes a crash due to a very similar cmp 
fencepost (no write). Not necessarily exploitable for remote code 
execution, unless code execution path can be affected later on. 

oom_dos.jpg - usually causes a OOM crash. Less interesting, unless 
you like to punish people who borrow your pictures for their blogs. 

random.jpg - causes mov fencepost of CPU consumption + crash. Didn't 
investigate in much detail. 

NOTE #2: MSIE comes with no sources, and reverse engineering is naughty. 
I didn't examine the renderer to see what went wrong; I see unbounded, 
user-dependent memory accesses, and that spells trouble. 

Vendor notification: 
-------------------- 

It is my experience that reporting and discussing security problems with 
Microsoft is a needlessly lengthy process that puts too much burden and 
effort on the researcher's end, especially if you just have a crash 
case, not a working exploit; hence, they did not get an advance notice. 

Bonus (OT) 
---------- 

Since piggyback request smuggling and fooling proxies and filters is a 
popular new pastime, some of you might find it entertaining to have a 
look at how various applications differ in handling duplicate instances 
of HTTP/SMTP message/NNTP headers that are, in common perception, 
"supposed to" occur only once. 

-- 
------------------------- bash$ :(){ :|:&};: -- 
Michal Zalewski * [http://lcamtuf.coredump.cx] 
Did you know that clones never use mirrors? 
--------------------------- 2005-07-14 00:29 -- 
http://lcamtuf.coredump.cx/silence/ 
_______________________________________________
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: