Safari "Carpet Bomb" Attack Code Released

snydeq writes "A hacker has posted attack code that exploits critical flaws in the Safari and Internet Explorer Web browsers. The source code can be used to run unauthorized software on a victim's machine, and could be used by criminals in Web-based computer attacks, security experts say. The public example of the attack code allows attackers to litter a victim's desktop with executable files, an attack known as 'carpet bombing.' In combination with bugs in Windows and Internet Explorer, attackers can run unauthorized software on a victim's computer."

Wrong section, eds!

[himself (66589)]

This is a _Windows_ Safari problem, not an _OS X_ Safari problem. And yes I RTFBlogPost.

Re:Wrong section, eds!

[Qwerpafw (315600)]

It's a Windows Internet Explorer problem, not a Mac OS X Safari problem.

the "bug" is that Safari has the users desktop as the default download directory, and will automatically download files if you go to some websites. This is normal and fine behavior. The problem is that Internet Explorer loads files from the desktop on launch, which means if you craft a malicious library and put it on the desktop Internet Explorer will happily load it.

Microsoft should fix IE to avoid loading files from the Desktop.

Re:Wrong section, eds!

[oyenstikker (536040)]

"This is normal and fine behavior."

No, it isn't.

Re:

[IntlHarvester (11985)]

Even aside from the IE issue and "carpet bombing", silently downloading things to the desktop makes it very easy to create a hack such as a fake "My Computer.exe" icon.

It really is bad UI behavior (on both Mac and Windows).

Re:

[Khyber (864651)]

No, the problem is that Safari doesn't utilize the functionality Windows has for marking files as safe or unsafe when it downloads something, thus allowing IE to open said files.

Safari isn't implementing the basic security that is implemented in Windows.

Re:

[gerardrj (207690)]

Marking the file safe or unsafe will likely not fix the issue. You aren't launching the DLL and IE isn't "opening it" like it would a bookmark or web archive or .jpg. It's including the DLL's code in to the execution environment of the parent process (IE) and thus bypassing any unsafe filesystem flag.

Then again, maybe I'm wrong. If you download and install a printer driver, are you warned the driver is unsafe the first time your try to print?

Re:Wrong section, eds!

[Chas (5144)]

No. It's a problem with Windows Internet Explorer that's exacerbated by a problem with Windows Safari.

Safari should NOT be auto-dumping files onto the Windows desktop. PERIOD.

There's enough blame to go around everywhere.

Re:Wrong section, eds!

[ClassMyAss (976281)]

Safari should NOT be auto-dumping files onto the Windows desktop. PERIOD.

Totally agreed. I'd go further - no website should be able to trigger any action on my computer that persists after I close the damn browser window without my explicit permission, apart from saving cookies and leaving an entry in my history log (even then, only if I've enabled both of these things).

That said, IE is worse here - downloading files without my permission is bad form, but a pre-installed system app loading DLLs from any old place that it finds them, especially one of the most common places to dump downloaded files, is just idiotic.

Shame on all.

Re:

[Darkness404 (1287218)]

But you *need* IE for the attack to be successful, its as much if not more of a MS/IE problem then an Apple/Safari problem. Granted, Safari is needed for the attack, but it is IE that executes the attack much as if downloading something in Firefox and then having another program execute it, Firefox is needed but it isn't as much of Firefox's problem then the other software.

Quick Workaround...

[Manip (656104)]

Here are two very quick temp' workarounds for the issue.

1) Launch IE from a location other than your desktop (e.g. Start Menu, Quick Launch Tray).

2) Go to Program Files\Internet Explorer, Create Shortcut, and then place that shortcut on your desktop. Make sure the "Start In" setting is set to any location other than your Desktop.

Better yet...

[HerculesMO (693085)]

Best workaround is to use Firefox.

Re:Quick Workaround...

[CastrTroy (595695)]

For me it runs even when launching from the quick launch bar, or from the start menu. For some reason, IE seems to like to load things from the desktop by default. For instance, to change your "view source" application from notepad to notepad++, you can put the following in a notepad.bat file on your desktop.

C:\Program Files\Notepad++\notepad++.exe %1

This problem seems to be two fold. First, Safari will automatically download stuff, to your desktop, without asking you. Secondly, IE will load DLLS from the desktop, just because they happen to have the same name as some other DLL it is looking for. I think the bigger problem here is with IE, because it doesn't matter how the dll got on your desktop, it shouldn't be using it.

Re:

[Khyber (864651)]

Do you know WHY IE likes to load stuff from the desktop?

If you disable active web content on your desktop (thus only allowing .bmp backgrounds, IIRC) I'll bet half this wouldn't happen. IE is integrated into the desktop so for it to run shit from the desktop makes sense.

Re:

[Fast Thick Pants (1081517)]

Red herring. It's got nothing to do with "Active Desktop". It's just the way Windows executables typically look for .dll files -- starting with the current directory and then each path listed in the PATH environment var.

In this case the shortcut to IE is launching the program with the user's desktop as current directory. First of all, it shouldn't -- probably it should be one level up from, there, in the user's home directory. Second, MS might want to rethink the way they hunt for .dll files for system

Re:

[Fast Thick Pants (1081517)]

In this case the shortcut to IE is launching the program with the user's desktop as current directory.

Hold the phone -- after several tests using CastrTroy's method, it appears that it doesn't matter one lick what the current directory is: IE will always give preference to executables on the desktop. 1) Eating crow and 2) Yikes! I still think Apple will be able to fix this first, and should.

This is a longstanding Windows flaw.

[argent (18001)]

This is not a security flaw in Safari, it's using what SHOULD be no more than a DOS attack on Safari to make an attack on the longstanding security flaws inherent in the Windows browser-desktop integration. The same flaws can be attacks with minimal social engineering ... convincing a significant number of users to download a file despite any warnings is NOT a hard process... the majority of malware over the past decade that have used related flaws in the Windows security model have managed to propagate usi

Re:

[A beautiful mind (821714)]

I am still boggled by the fact that Microsoft didn't fix the deep problems here ten years ago.

The simple solution would be to provide a damn package manager, with public repositories and trustworthy install mechanism. People need to be educated out of grabbing any software from third party sources, unless they can't find it in the repository and they really need it and verified that it's a legitimate copy from a legitimate source.

Re:

[initdeep (1073290)]

Well killing off stupid users is sort of self defeating isn't it?

Re:This is a longstanding Windows flaw.

[brunascle (994197)]

I'd say it is a security flaw in Safari, but for different reasons. As the same blog explains [fc2.com], you could have Safari download an executable to the desktop that pretends to be e.g. Internet Explorer. If they normally launch IE from the desktop, they could click the fake IE next time, running arbitrary code.

Re:

[argent (18001)]

As the same blog explains, you could have Safari download an executable to the desktop that pretends to be e.g. Internet Explorer. If they normally launch IE from the desktop, they could click the fake IE next time, running arbitrary code.

Yes, that's a standard part of a social engineering attack. This does make social engineering attacks easier, and should be fixed (let's start by downloading to something like %PROFILE%\Downloads instead of the Desktop). This is similar to the problem where Safari on OS X

Re:

[Sloppy (14984)]

you could have Safari download an executable to the desktop that pretends to be e.g. Internet Explorer. If they normally launch IE from the desktop, they could click the fake IE next time, running arbitrary code.

I'd call that a fundamental flaw with the Windows environment itself. It sounds like this "desktop" thing is used as both a temporary scratchpad for miscellaneous data from arbitrary untrusted sources, and as a repository for locally trusted executables. Someone at Microsoft needs to get it strai

Re:

[anomaly256 (1243020)]

Just FYI, it's not the browser-desktop integration causing the problem with IE, it's how the win32 dynamic linking mechanism works

Re:

[argent (18001)]

Is it this one? "While trying to load some of those files, it does not provide the full path of the DLL file to the function which loads the DLL file to the memory, and therefore Windows will search for this file in the user's machine using the directories provided in the PATH environment variable, and will load the first match it will found."

If so, why is %PROFILE%\Desktop in %PATH%?

Oh, no, it's this one: "While this is true, the behavior of the "DLL Search Order" (when it's disabled) is to look for the DL

Best Solution

[Skye16 (685048)]

Clearly the quickest way we can get Apple to fix this is to host this attack on all of our own websites, with the .exe in question being the uninstall program for Safari.

As soon as the attack centers on an Apple product, they'll start moving their ass. Until then, it's "not [their] problem".

Re:

[Entropy2016 (751922)]

It's something Microsoft has to fix. The article is your friend.

Re:

[Skye16 (685048)]

I'm sorry, but allowing a malicious website to provide hundreds or thousands of executables on my desktop is *still* an Apple bug. What's worse, it's the root cause. Yes, Windows and IE have a flaw that allow that file to be executed, but it wouldn't be there in the first place - especially in such quantity - if the flaw in Safari didn't exist first.

As you say, the article is your friend.

"The Safari bug, originally disclosed on May 15 by security researcher Nitesh Dhanjani, allows attackers to litter a vi

Re:

[oahazmatt (868057)]

Half of the problem is with Safari, the other half is with IE. Let's give credit where credit is due.

If it weren't for Safari downloading the files to the desktop by default, they wouldn't get there.

If it weren't for IE opening these files from the desktop by default, they wouldn't open.

Now, if you'll excuse me, I'd like to feel completely secure. I'm going to go install my old copy of OS/2 Warp v3 and Netscape Communicator.

Re:

[ClassMyAss (976281)]

Someone else posted somewhere here that it doesn't matter if the file is marked or not, and that if you download the file from IE or Firefox it is STILL picked up and loaded from the desktop by IE. Sounds like part of the problem is that dll's aren't being checked for safety before loading; whether this is a general "feature" in Windows or something IE specific, I have absolutely no idea, I haven't used Windows in a while so I can't check myself...

Re:

[Entropy2016 (751922)]

The person I was responding to was talking about executing unauthorized exe on on another person's computer (to uninstall Safari). That part of the attack is a Windows+IE issue that Microsoft has to fix.

Sure, Safari (on Windows) can carpetbomb & spam your desktop. That's potentially annoying (but ultimately doesn't harm your system).

There's a distinction between Safari "making available" the malicious executable versus it actually being executed, which like I was saying, the person I was responding to

MSFT needs to fix this ASAP

[aristotle-dude (626586)]

Having Apple change the default location from ~/Desktop to something else only for windows would not solve the real problem. The real problem is that windows should be doing the flagging of the file as potentially unsafe and IE should not be loading DLLS placed on the desktop regardless of how they got there. It is not the responsibility of the browser to flag it a file as potentially unsafe. Windows should either provide a well documented API for setting an unsafe flag on downloads separate from any IE/IE7 code or windows should be monitoring downloads and flagging them.

Regardless of what the default is in Safari or even Firefox, a user can still change that default to anything they want including the desktop.

As others have pointed out, the downloads folder is a Leopard specific feature used by Safari when running under Leopard and the executable warning thing is also a Leopard feature.

Who uses safari for windows and IE?

[wattrlz (1162603)]

Personally I think the bigger issue is that Safari will auto-download, auto-mark-safe, and auto-run files silently. IE's broken too, but either one of the players involved could render this exploit moot. Let's see who responds first before stoning someone to death.

I still don't see why someone would be browsing around in safari and then open up IE. A regular user's likely to only use his favorite browser and a dev who needs to view the same site in multiple browsers would probably notice that there're a bunch of new .dll files all over the desktop.

Re:Secure from the ground up!

[spud603 (832173)]

RTFA. Actually, it looks like this is a windows problem. Safari automatically downloads a file to the desktop. Then when you start Internet Explorer it runs the file on your desktop and there is the problem.
So the real issue is that Safari can be told to automatically download a file while internet explorer will automatically run a malicious dll from the desktop. actual post and proof-of-concept code here [fc2.com].
seems like a misleading summary to me.

Re:Secure from the ground up!

[Colonel Korn (1258968)]

RTFA. Actually, it looks like this is a windows problem. Safari automatically downloads a file to the desktop. Then when you start Internet Explorer it runs the file on your desktop and there is the problem.
So the real issue is that Safari can be told to automatically download a file while internet explorer will automatically run a malicious dll from the desktop. actual post and proof-of-concept code here [fc2.com].
seems like a misleading summary to me.

IE won't run anything "automatically." It sounds like the problem is that Safari both autodownloads to the desktop and then tells IE to open that file on its next load.

Re:

[bluelip (123578)]

IE will load its DLLs automatically. If the current PATH contains the DLL, IE will use that version instead of the system version.

Re:Secure from the ground up!

[spud603 (832173)]

from TFA:

The problem originated from an error that Windows Internet Explorer will load some program library files(DLL) from user's Desktop instead of its own library file folder(usually C:\WINDOWS\SYSTEM32). Apple's Safari for Windows downloads and saves requested file to user's Desktop by default - this default behavior itself does not constitute a mistake.

The 'workarounds' suggested by MS include "Change the download location of content in Safari to a newly created directory". I don't actually know what's going on with this, but it seems like it's IE opening an improperly-named (or maybe there's some bad meta-data that comes along with it?) file from the desktop, no matter how it got there.

Closest resources first

[RingDev (879105)]

Sounds like a scope issue. Microsoft apps are designed to look for resources/references closer first, then further as needed.

For example, if IE needs to use mm.dll it will first look in the working folder, if it doesn't find it there, if will check the system's path variable and see if it can find the library in any of those folders.

In this specific case, if you are running Safari, it can auto download a new file, say, 'mm.dll' to your desktop. Safari doesn't care about it, BUT, the next time you start IE f

Re:

[deke_kun (695166)]

This is exactly what is happening.

And yet this is listed as a Safari flaw?

Come on, how insanely insecure is it to run executable code from the desktop! Hasn't windows had protection on the windows and system32 directories for about 6 billion years now for this very reason? And then they go and make it pull executable code from just about the least secure place on any PC.

From where I'm sitting this is a massively Microsoft problem, but their suggested "fix" is still the easiest solution by far. B

Re:

[clang_jangle (975789)]

But it is a Safari flaw. If I wrote a browser and released it for multiple OSs I'd consider it my responsibility to eliminate all possible security breaches individually for each version. Though I am an Apple user and really dislike MS, it seems to me that Apple simply didn't finish the job on their windows version of Safari. True, windows is a real PITA to port software to, with all the poor security choices MS has made -- but a job worth doing is a job worth doing properly. Users of WinSafari have a right

Re:Secure from the ground up!

[FatMacDaddy (878246)]

You know, this is pretty clearly explained in the article. To quote: "Microsoft's advisory says that the vulnerability has to do with the way Windows handles desktop executables and recommends that Windows users "restrict use of Safari as a Web browser until an appropriate update is available from Microsoft and/or Apple."

So yes, IE is in fact autoloading executables from the desktop. It's Safari's vulnerability to carpet bombing that sets the stage, but it's IE and Windows that cause the big boom.

Re:Secure from the ground up!

[Richard_at_work (517087)]

Read Slashdot: Microsoft Urges Windows Users To Shun Safari [slashdot.org] - it explains what happens in more detail.

Basically, on Windows Safari automatically downloads files, in imitation of its behavior on OSX, but whereas on OSX it downloads them to a nice ~/Downloads directory on Windows it downloads them to the desktop. Also, on OSX Safari tags the downloaded file as 'unsafe', but it fails to use the Windows functionality to do the same on Windows. This leaves a whole load of files that you never asked for or wanted lying around on your computer in a state that is one step away from being executed.

This 'attack' allows a malicious person to force Safari to dump thousands of files on your desktop, which in and of itself is not a nice thing, but when coupled with other exploits it can lead to code execution of these files you never wanted in the first place - whether those exploits are patched by the vendor (Microsoft) or not, we both know that a significant portion of desktops are not kept fully up-to-date with security releases.

mod parent up

[spud603 (832173)]

very informative.
If Windows has an "unsafe" flag for files, it should be used by Safari. Also, I find using desktop as default download space incredibly annoying (yes, i'm looking at you firefox).
That said, IE should also know better than to execute random files from the desktop, which seems like the nastier issue here.

There is one

[Titoxd (1116095)]

If Windows has an "unsafe" flag for files, it should be used by Safari.

Windows has it. It's the Attachment Execution Service [bartdesmet.net], located in the Alternate Data Streams [wikipedia.org] in NTFS.

Re:

[gerardrj (207690)]

Even if Windows has an "unsafe for execution" flag for files, the DLLs in question aren't really being launched through the new process/application launch APIs that would implement such a flag.
These files are being loaded as trusted libraries of shared code that likely bypass anti-virus and other such protection apps.

Yup!

[nobodyman (90587)]

It would be easy enough to test this out though. manually download this DLL using IE (which marks the file as unsafe), then fire up IE7.

I tried it out: the exploit still works when you manually download the file using IE instead of Safari. So either IE isn't marking downloaded executables as unsafe either, or IE ignores this flag when loading DLL's. Either way it undermines the"Apple is at fault" argument.

Carpet bombing is still an issue, if for no reason than it is an annoyance.

Re:

[peragrin (659227)]

um safari at least for me downloads directly to the desktop. then again when the download finishes instead of auto opening the file OS X pops up a dialog to manual confirm that I downloaded an application/disk image/zip file. where as jpgs, gifs, pdfs just save automatically.

Re:

[Pope (17780)]

but whereas on OSX it downloads them to a nice ~/Downloads directory

No it doesn't. It downloads to ~/Desktop by default. You have to change that yourself. (Unless 10.5 has a new folder that 10.4 doesn't)

Re:

[Jabrwock (985861)]

Yes, the "Downloads" folder was introduced in 10.5.

Re:

[mweather (1089505)]

It shouldn't, but absent any idiotic vulnerabilities in other software, it's just an inconvenience to clean up the downloaded files. No damage is done.

Re:

[mweather (1089505)]

In this case Application B and the system are one in the same.

Re:

[by Anonymous Coward]

First, read the article.

Second, this is about a Windows flaw that Safari has not addressed (rather Apple) in its current iteration. Apple's browser can be considered a "patsy" in this... and MS is trying to pass the buck (so to speak.)

Third, the "open safe files after downloading" is old news. Get a new schtick. ;)

And Fourth, grow up. This isn't about Apple's security, it's about Microsoft's... and Apple's inability to prevent "stupid is as stupid does" on a Windows machine. They're good... just not mira