Public Exploit For Windows JPEG Bug

Patch is Already Out by darkmeridian · 2004-09-23 00:10 · Score: 5, Informative

The patch for this one is already out. Furthermore, SP2 systems do not have this vulnerability unless Office is installed. SP2 by default has auto-updates enabled. And for Office to be exploited in a SP2 system, the user has to open the file manually.

Code is always buggy. Even Firefox had a JPEG vulnerability of its own. This is dumb ownership, if this bug becomes prevalent.

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Re:Patch is Already Out by Gzip+Christ · 2004-09-23 00:17 · Score: 5, Funny

This is dumb ownership, if this bug becomes prevalent.
Phew... I was worried there for a second. It's a good thing we can rely on Windows users to not be dumb, otherwise the Internet would be bogged down in viruses, spyware, and spam.
Re:Patch is Already Out by darkmeridian · 2004-09-23 00:21 · Score: 4, Insightful

This is dumb ownership, if this bug becomes prevalent.

Phew... I was worried there for a second. It's a good thing we can rely on Windows users to not be dumb, otherwise the Internet would be bogged down in viruses, spyware, and spam.

Well, most users are, uh, stupid. Even if we used Linux, in order to make it simple enough to use, there will be vulnerabilities. For example, getting people to use "sudo" with a limited account makes sense to you and me, but might confuse the heck out of some newbie in Tennessee.

So it is not a Windows-specific problem. If Linux ever becomes popular as a desktop platform, we will then have dumb Linux users.

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Re:Patch is Already Out by maxwell+demon · 2004-09-23 00:39 · Score: 5, Informative

Well, you know, that's called a software bug. A software bug is by definition something you didn't intend.

Actually, it's a buffer overflow. A buffer overflow means that there is some area of memory reserved for some data, and then there's more data written to it than fits in. This causes some other data to be overwritten; if that other data happens to be a return address (basically a number which tells the computer where to continue after finishing the current task), then you can get the computer to execute arbitrary code which is in memory - including the code you just conveniently placed into the memory as "image data".

I don't know details of the JPEG image format, but with a simple bitmap format, a buffer overflow might happen as follows:

The image contains the number of pixels, and the bytes per pixel. The program takes those numbers, multiplies them, and reserves that much memory to take the pixel values. Then it reads the rest of the file as image data into that memory.

Now, this simple program for this simple image format may be easily exploited: Just put more data into the image than the product of number of pixels and bytes per pixel. Then the program as written will not reserve enough memory for that data (because the values at the beginning don't tell the truth), and therefore the data will overwrite anything following the data.

Ok, the fix is easy: Don't read more data than you allocated memory for. The problem is that on one hand, there are C standard functions which make it easy to get that wrong, and second, there can be more subtle ways to produce the same result. For example, the multiplication could overflow, resulting in too little memory being allocated, while the given number of pixels is read in (under the believe that you have reserved enough memory for that).

And yes, buffer overflows happen in open source software as well as in Microsoft software.

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Re:Patch is already out by BoldAC · 2004-09-23 00:43 · Score: 5, Informative

Come on guys! This is slashdot!

Where is the downloadable link to the second proof of concept code?

Here's the link to the first POC:
http://www.gulftech.org/?node=downloads

The first POC just generates the buffer overflow crash. Interesting enough, on an unpatched system, just having the jpg on your desktop caused by explorer to crash - repeatedly. I am assuming as XP tried to generate the thumbnail. However, if viewed through a web page, I could view it fine.

I've been looking for the second POC code since yesterday. It supposedly opens a cmd prompt when the crafted jpg is viewed.

AC
Re:Patch is already out by Trigun · 2004-09-23 00:48 · Score: 5, Informative

http://www.k-otik.com/
You can find it all there, including a C program that fires off a local cmd shell.

Only for use as a security lesson and ethical hacking.
Re:Patch is already out by KidHash · 2004-09-23 01:03 · Score: 4, Informative

Which isn't really that helpful, however, there's space for 2500 bytes of shell code (ie, lots of space left in the example on k-otik) for writing something with a reverse-shell - in fact, this has already been done, it just isn't public There's also a newer example on k-otik Which adds an administrator account to the system it runs on, however, you'll have to edit some of the code yourself - script-kiddy-proof.
Re:Patch is Already Out by Junks+Jerzey · 2004-09-23 01:29 · Score: 4, Informative

That's pretty low man. I've coded plenty before and I've never encountered an instance where I can't check to see if a buffer overflow has occurred. I can't help but feel that all of these exploits are just sloppy programming.

It isn't sloppy programming as much as the rules having changed. It used to be that you'd write an image decoder (or *any* program that reads an external file format), and you'd either (a) assume that the file structure is correct (because if it isn't, then it had to be created by a bad encodder), or (b) do some rudimentary checking to catch basic problems (such as a missing file id tag in the first bytes). And the worst that could usually happen was that your decoder would crash or become unstable. Really, this is how things have been, how coders have worked. Remember, it applies to every single type of external data read into a program: serialized data saved by library classes in C++, Python, etc., bytecode files read by a virtual machine or other interpreter, help file indices, intermediate object files...everything.

Moreso, just because you don't have buffer overruns doesn't mean you're in the clear. You have to check for tremendous files, too. What if someone passes you an image file that's correct and compressed, but decompresses into a 100,000 by 100,000 32-bit image? Even if you had the memory to decode a large file, the resources it takes up makes it essentiallly a denial of service attack.

These are tough issues.

Spammers by sleepnmojo · 2004-09-23 00:11 · Score: 5, Interesting

The biggest problem here is when spammers use this in there opt out link. This would probably be much more effective than the scrollbar hack they are using now. It just has to render the damn page, and wham you're infected.

Re:Spammers by don_carnage · 2004-09-23 00:13 · Score: 4, Informative

HTML-formatted email + Outlook = Bad day for Grandma.

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pr0n by Lord+Prox · 2004-09-23 00:14 · Score: 5, Funny

Damn. Now in addition to worring about going blind I also have to worry about catching something.

Related links? by caluml · 2004-09-23 00:14 · Score: 4, Interesting

What's all this stuff in the related links? . Bug whitepapers . Best deals: Bug . More Bug stories . Security whitepapers . Best deals: Security . More Security stories . Windows whitepapers . Best deals: Windows . More Windows stories . Microsoft whitepapers . Best deals: Microsoft When did that start happening?

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Are you patched? by UnderAttack · 2004-09-23 00:14 · Score: 4, Interesting

These early POC exploits are covered in todays
ISC Diary. Note that now there is a script to generate images to add an Admin level user (username "X").

Not too long until we see a remote shell.

Some people are tlaking about seeing it used in an MSN Messenger worm.

The hard part about patching this one is that a lot of third party software may overwrite the Windows JPEG GDI library with its own older version :-/

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Re:Are you patched? by ajs · 2004-09-23 01:33 · Score: 4, Funny

Not too long until we see a remote shell.

And therein lies the rub. For the people that write these things, it's reaching the point of diminishing returns in terms of getting the tools installed that they need in order to efficiently, remotely manage these boxes. It was all fun and games when you just wanted 10,000 boxes to send out ping-of-deaths or SYN floods, but now you have to manage a farm of zombies and get real work out of them. The competition is fierce and the other guy is trying just as hard as you are to get large-scale admin working, and of course, like all large-scale Windows installations, they're finding that this sucks.

Several things would help:

* A virtual OS layer is needed so that the user can have Windows for their games, but the crackers can do their admin from a maintainable OS. Heck, even DOS would be more managable.

* Users should make themselves available to the crackers for physical admin needs like reboots.

* Microsoft needs to stop pushing these auto-updates. It's not as if the crackers can't find new holes faster than MS can push the updates, but the rapid change to an installed base is just too difficult to remotely manage. Bill: you're killing profits here!

Overall, we just need to start making doing business on the Internet more friendly. I don't understand why people can't understand this!

PS: ;-)

safe sex by gusmao · 2004-09-23 00:16 · Score: 5, Funny

Does that mean when you watch porn on the Web it is not safe sex anymore? Damn it!!!

Patch is already out by Jeffv323 · 2004-09-23 00:17 · Score: 5, Informative

Pick your OS and download it here

Also, if you have SP2 or uh, don't use MS software, you're fine :)

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Re:So what? Burn all JPEGs day? by Ford+Prefect · 2004-09-23 00:17 · Score: 4, Informative

Shall we announce a "Burn all JPEGs" day because of Microsoft security issues now and switch all to PNG?

Well, you could, but don't forget the recent bugs in libpng... ;-)

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patch has been available for a while now by jeffs72 · 2004-09-23 00:18 · Score: 5, Informative

And it actually works fairly well. It scans for any program that reads these files and makes sure they don't have the bug in them. If it can't patch them, it bugs you about it so you can find a fix for the app. Only Microsoft apps of course, I don't think Adobe wants Microsoft pushing out software updates for them.

Most of the users I have to support aren't savvy enough to add a printer (omg, with active directory it's like 3 mouse clicks) or install software or apply updates (we use some banking software and it notifies you with a text box to click "OK" and then "File, Update" but I still get called on it every time). That's why at our offices we use Microsoft System Update Server (SUS). It lets us approve patches and then roll them out to all the clients in the domain automagically.

I shudder to think what would happen if I tried to roll out firefox or mozilla to everyone. I'd probably get calls that their "e" was missing and they couldn't connect to the internet. I swear, some people just shouldn't be on computers.

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Re:I cannot help but grin ... by Pieroxy · 2004-09-23 00:18 · Score: 5, Insightful

but I have a strong suspicion
Everyone is entitled to its own suspicion.

The level of polish and craftsmanship of open source software
As opposed to the level of polish and craftmanship of Microsoft's products, of which you know nothing. So you are comparing apples to ... well something you just don't know. Good luck for being objective.

--
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Re:Single sign-on for a browser? by pcardno · 2004-09-23 00:19 · Score: 4, Informative

You can do something with Active Directory to enable single sign on so that your browser can use your Windows credentials to figure out who you are.

An example being that I log into my laptop on the corporate network in the morning, but then never need to log into our Intranet. It uses my Active Directory credentials to figure out who I am, so displays my own customised and personalised Intranet settings.

I'm not too sure how it works but it's very handy!

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Re:Almost... by lphuberdeau · 2004-09-23 00:21 · Score: 5, Insightful

Browsers are not the only problem. Many companies use outlook as a mail client. Someone could simply include a jpeg image to the mail and since images are loaded by default, they would infect everyone. Seriously, the only way around this is to update software. Microsoft already has a patch for this I think.

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hmm someone predicted this by minus_273 · 2004-09-23 00:24 · Score: 5, Insightful

about a year or so back there was a slashdot story about i think macafee researchers talking about viruses being transmitted over images. Everyone called it stupid market speak from a firm trying to sell more AV products by scaring people with somthing that is not possible. I think we all need to offer them an apology. I think this is a bizzare parallel to when people used to joke about email viruses way back in the min 90s. Kind of sad that it is real now. It will be even more so when images are used for exploits too. Though, i suspect those at most risk are those that go to websites looking for lots of images...

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Re:hmm someone predicted this by stromthurman · 2004-09-23 02:02 · Score: 4, Informative

And for further information, the virus MacAfee reported on was called Perrun. You can read more about it here. The advisory was issued in mid 2002, and is entirely seperate from the issue at hand.

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Hard to patch by Manip · 2004-09-23 00:25 · Score: 5, Interesting

This bug exists in most Microsoft Software. So for someone to patch they can't simply connect to Windows Update and consider themselves safe, they also have to patch Office, Visual Studio, some Microsoft Games, Server Software (misc, not covered by Update) and more.

So don't sit there on an SP2 system and consider yourself safe. There is more than likely a whole host of ActiveX controls just waiting to be called and exploited by this bug.

Also note that some applications written in Visual Basic can also be exploited.

Re:Knew it by jb.hl.com · 2004-09-23 00:28 · Score: 4, Funny

It's a gaping security hole.

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Microsoft patches by Anonymous Coward · 2004-09-23 00:29 · Score: 4, Funny

You can make a big fucking quilt with all those patches they keep giving out!

Re:Can someone confirm... by Sanity · 2004-09-23 00:29 · Score: 4, Informative

The recent JPEG vulnerability in Firefox is a separate issue. Firefox is OSS, and thus cannot use closed-source libraries such as the MS one in trouble.

If that were true, then you wouldn't be able to use OSS on a non-OSS operating system, since eventually the OSS needs to link with non-OSS code.

Re:Almost... by enigmals1 · 2004-09-23 00:29 · Score: 5, Insightful

Switch to Firefox?! Why, what's that gonna do for you? The exploit is in almost every major app Microsoft makes that handles any graphics, including Windows itself, .Net Framework, all Office products, etc.

People are so quick to blame IE when there's so many other products they can go after. ;)

Re:PNG too? by Deviate_X · 2004-09-23 00:30 · Score: 5, Informative

Re:Almost... by SenseiLeNoir · 2004-09-23 00:33 · Score: 5, Interesting

This is exactly the problem I fear. All it takes is one spammer/cracker to bulk mail a hundred of pictures to random HTML accounts (Hotmail, etc).. and you can see exactly where this is going to lead.

Also those who use Firefox may not be 100% protected, because consider this scenario.

1. Install Firefox
2. Set Firefox as default browser
3. Use MSN Messenger.
4. MSN messenger pops up "you have new hotmail"
5. Click link to see new mail, MSN Messenger opens up in INTERNET EXPLORER despite setting firefox as the default browser.
6. You are owned.

I am more concerned that after this, people may even mistakenly critisize Firefox, thinking that Firefox was there default browser, and that they got infected via firefox, instead of IE.

"I set up this firefox thingie, and set it as a default browser, yet I still have a virus, by just reading my email. Firefox is just as bad as IE"

A second attack vector could be to change the mimetype of the JPEG, causing Firefox to download, then open it in the system handler for JPEGS.. and a possibility of being owned that way.

Still this may also be very good grounds for a class action against MS, as they are not honouring a users request NOT to use IE.

This all goes to prove, MS is a security hole, that can even make secure applications appear insecure

Ow, my head hurts from thinking of this.. let me get some Paracetamol.

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Re:Almost... by YrWrstNtmr · 2004-09-23 00:39 · Score: 4, Informative

Many companies use outlook as a mail client. Someone could simply include a jpeg image to the mail and since images are loaded by default,

OL2003 has image loading off by default. "RightClick to display this image."
Of course, most people are on earlier versions, but at least MS is putting in an effort to stem the tide.

Everyone knew it by Pan+T.+Hose · 2004-09-23 00:40 · Score: 4, Funny

I knew there was something wrong with Goatse when I saw it!

Everyone knew it was a backdoor.

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Comment removed by account_deleted · 2004-09-23 00:42 · Score: 4, Informative

Comment removed based on user account deletion

Re:I cannot help but grin ... by YetAnotherName · 2004-09-23 00:44 · Score: 4, Interesting

of which you know nothing

As a user of Microsoft products, I witness their lack of stability, their tendency to crash or exhibit bugs, and their uncanny ability of corrupting user data, and so forth. After putting up with them for so long, I know quite a bit about them.

Moreover, I used to be an employee. I worked at the Redmond campus. I know both the quality exhibited on the outside, and the quality that goes into the products on the inside.

I do indeed know something.

THIS HAS NOT BEEN FIXED, url inside by Anonymous Coward · 2004-09-23 00:44 · Score: 5, Interesting

http://sylvana.net/test/AP4.jpg

will crash IE on an updated xp sp2 system.

Re:THIS HAS NOT BEEN FIXED, url inside by Jan-Pascal · 2004-09-23 00:59 · Score: 4, Insightful

Confirmed on WinXP SP2, all Windows updates, all Office updates. OK in Firefox (1.0PR), but crashes IE 6. And it's not even a goatse link: http://sylvana.net/test/AP4.jpg

AutoUpdate not good enuff by DanMc · 2004-09-23 00:55 · Score: 5, Informative

Autoupdate and Windowsupdate only install a fraction of the patches released for this bug. (Windows OS and IE basically)

WindowsUpdate does install a "GDI+ Detection Tool", but I have run this tool on systems with unpatched Visual Studio, Outlook, and Office and it does not detect that the patches are missing. I looked at the strings in this tool, and it basically looks like it checks for MS Photo software.

Manually visiting "officeupdate.microsoft.com" and running those updates will probably cover the most common attack vectors (Outlook, Word), but how many people do this on a regular basis? My users are not admin-level (yet) so they can't use this update site.

Incidentally, every default configuration of IE/Word I have seen allows DOC files with jpegs to be opened in the browser window with no prompting. It will not be hard to get people to run the exploits, and there's plenty of ways for worms to automate themselves without users opening things.

I'm working on a script to detect and run the patches (there's about 17 of them for this bug) but it's going to be a while because of the pre-reqs for many of the patches, and the very specific revisions that must match the patch. "If Visio 2002 is installed, detect which Visio SP level is running. If it's SP0 or SP1, run Visio SP2, then reboot, and run GDI patch"...

Sorry if I'm spreading panic, but this bug sucks.

Re:Almost... by AstroDrabb · 2004-09-23 01:08 · Score: 4, Informative

We use Netegrity as well. However we went against the single sign-on thing since it was less secure. Our users get stopped by a Netegrity form and enter their username password and then can go to any corporate intranet web app without signing in again until they close their browser or the session expires (about every hour). Firefox/Mozilla already support Windows authentication for single sign-on. It prompts a user for their name and password instead of just silently sending it. The user can even check a "remember password/username" option so they don't have to enter it again. Some management tried to get the admins to turn on windows authentication with Netegrity but the admins and we programmers stood our ground and said how bad an idea it was. Our users can get to all types of personal information and personal financial information on our corporate intranet. It is really dumb to not authenticate a user at least once per session. If a user walked away from their desktop without locking it (happens all the time), anyone could walk up to their box and get to all their personal data if we used just windows authentication. We do have a policy that locks a desktop after 15 minutes, however that is still a 15 minute windows for someone to do get to someone elses personal and financial data.

Tell your management to turn off the Netegrity/windows authentication and use Netegrity form authentiation over SSL. Also, there is no reason why your users cannot user Firefox/Mozilla since it has had cross-platform support for Windows authentication for a few versions now.

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Re:Almost... by tcr · 2004-09-23 01:37 · Score: 4, Informative

Now, to convince my company's managers to switch their userbase to Firefox

Before we get too smug, the article (anyone read those?) did mention an (albeit unrelated) vulnerability in Moz amongst others (PNG support) from August. Reproduced below.

To avoid getting the flameproofs on, I should point out that Firefox is my browser of choice. But let's avoid the whole stones and greenhouses scenario, yeh?

update Six vulnerabilities in an open-source image format could allow intruders to compromise computers running Linux and may allow attacks against Windows PCs as well as Macs running OS X.

The security issues appear in a library supporting the portable network graphics (PNG) format, used widely by programs such as the Mozilla and Opera browsers and various e-mail clients. The most critical issue, a memory problem known as a buffer overflow, could allow specially created PNG graphics to execute a malicious program when the application loads the image.

Among the programs that use libPNG and are likely to be affected by the flaws are the Mail application on Apple Computer's Mac OS X, the Opera and Internet Explorer browsers on Windows, and the Mozilla and Netscape browsers on Solaris, according to independent security researcher Chris Evans, who discovered the issues.

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Re:Almost... by dtfinch · 2004-09-23 01:39 · Score: 4, Informative

This usually works:
rundll32 advpack.dll,LaunchINFSection %systemRoot%\INF\msmsgs.inf,BLC.Remove

He knew it... by insac · 2004-09-23 03:30 · Score: 5, Interesting

When I was in University there was an old professor who gave us to write relation about JPEG format with code examples...

When we were leaving his room he gave us this advice: "Beware the JPEG virus". It was 9 years ago and he was quite old and sometimes he acted/talked nonsense so we made fun of his advice (we thought: since it was not an executable file, how could it bring a virus): but he was right and we were wrong..

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Public Exploit For Windows JPEG Bug

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