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Windows XP Flaw 'Extremely Serious'
scottott wrote to mention a Washington Post article with the news that the security hole we mentioned on Wednesday has widened. Computers can now be infected just by visiting infected web sites, or looking at images in the preview panel of older versions of Outlook. From the article: "At first, the vulnerability was exploited by just a few dozen Web sites. Programming code embedded in these pages would install a program that warned victims their machines were infested with spyware, then prompted them to pay $40 to remove the supposed pests. Since then, however, hundreds of sites have begun using the flaw to install a broad range of malicious software. SANS has received several reports of attackers blasting out spam e-mails containing links that lead to malicious sites exploiting the new flaw, Ullrich said."
"Mac and Linux computer users are not at risk with this attack, even if their computers run Microsoft programs such as Office or the Internet Explorer Web browser."
Amazing!
Guys, you keep posting that same story about a serious security flaw in Windows.
If you use Windows, go get the vmware browser appliance and use it - connecting to the internet through a virtual machine is like wearing gloves in the OR - it's just common sense.
http://www.vmware.com/vmtn/vm/browserapp.html
Using plain ol' text since 1968
until a patch is released.
IAAL
When is a Windows flaw ever not extremely serious?
Would someone tell me if the "just by visiting an infected site" link, is a link to an infected site, or an article about the infected sites?
I needed a bit of underground info(cd key) and went to the best site for that and with out thinking I used IE -- couldent have shut my browser down fast enough.
Spent the next few hours removing all the junk that installed, I was lucky no root kits were installed.
Have you been touched by his noodly appendage?
...is brought to you by http://update.microsoft.com/
Programming code embedded in these pages would install a program that warned victims their machines were infested with spyware, then prompted them to pay $40 to remove the supposed pests.
Where do you send the money? And they aren't afraid of getting caught?
He who knows best knows how little he knows. - Thomas Jefferson
scottott wrote to mention a Washington Post article with the news that the security hole we mentioned on Wednesday has widened. Computers can now be infected just by visiting infected web sites, or looking at images in the preview panel of older versions of Outlook.
There are two major factual errors here. One, the security hole has not "widened" - the scope of exposure is exactly what we read about Wednesday. Using shimgvw.dll to view a specially constructed WMF file results in system compromise (web site viewing of malicious WMF, previewing, opening w/MS picture and fax viewer, etc). The hole is exactly the same - exposure has increased, but the hole has not widened. Two: the web sites are not infected, they are malicious. The system is infected after visiting a malicious web site.
The full (well, as full as it is now) MS advisory is here. I'm not very pleased with how MS is handling this at all, but that does not excuse this shoddy "journalism". How hard is it to state facts correctly? All you had to do was change a few words, and it would have read much more accurately:
scottott wrote to mention a Washington Post article with the news that the security hole we mentioned on Wednesday is now affecting many more users. Computers can now be infected just by visiting malicious web sites, which are now rapidly increasing in number, or looking at images in the preview panel of older versions of Outlook.
For the last sentence, note that I sent mysefl WMF files win Outlook 2000 and 2003 while running Sysinternals process explorer and never saw shimgvw.dll called. Opening a WMF attachment called it, but not previewing, so there might be three errors, but I didn't test all versions that way, so I don't know...
Those of us who use free operating systems shouldn't be too complacent. This exploit is serious because the WMF rendering library has full access to the user's data, and (at least on a 'home' setup where it's a single-user machine) access to the whole PC.
But it was really just bad luck that the bug happened to be found in the Windows WMF library and not, say, its Unix/X11 equivalent. Or libpng, or zlib, or whatever. Anyone who thinks otherwise is deluded. All software has bugs, and even if the quality of the free libraries is ten times higher (unlikely) there will still be plenty of memory tramplings and buffer overruns.
So, when the next vulnerability is found in a commonly used Unix library, will we be in any better position? Not really. Still the library is linked into the application and runs in the application's address space. It has access to all the files the app does, and traditionally on Unix that means everything the user has access too. Your email application may only need to read ~/.mail_settings and connect via IMAP to some host, but it runs with permission to overwrite any file owned by you and connect on any TCP/IP port it wants.
Why does the WMF rendering code need to run with any more permissions than: read a block of memory with the WMF file, and write a block with the rendered bitmap? (Or perhaps make display / GDI calls, if performance is a concern.)
What support is there in Unix operating systems for running common library code with only the privileges it needs? As far as I know Linux has no simple way to run a dynamically-linked library (.so file) in its own address space or without permitting it to make system calls. So when the next exploit is found in a common Linux library - and it will be found - the situation will be just as embarassing.
-- Ed Avis ed@membled.com
Okay, really, she said Arkanoid, but you get my point.
Have you been touched by his noodly appendage?
If all you are doing is browsing the web, there is absolutely no reason to not do it in a sandbox. In fact, I don't get why all browsers run in sandboxes. Why do they *ever* need access to the host OS? If they need to save downloaded files, they can do so via a mounted share. At least in a sandbox they cannot execute privilidged code, at most they could infect executabes on said share.
This is not an ie flaw. This is a Windows flaw. You can still be affected with other browsers, you just have to try harder. Anything using the Windows DLL that does the WMF processing will be affected.
When will Windows be ready for the desktop?
My browser touches all sorts of things in the host OS, from the sound card to files that I upload and download. Luckily when I get AIM spam for foo.exe or some other sillyness I don't get far unless I type 'wine foo.exe', then even then ;-)
The true challenge is how to dial in the security to a reasonable level. Problem is getting all the millions of programmers to adopt more secure standards combined with the users, IT managers, etc.. that deploy the apps on desktops. Then, getting that out across the millions of home users too. Daunting task.
You can't prove a rootkit doesn't exist on your system, unless you have a checksum database on read only media, and some sort of hardware (not firmware) method of computing those checksums.
You can't even be reasonably sure of it without at least some checksumming system like tripwire.
All you are doing is scanning for certain known rootkits. That's a weak strategy that's reactive and guaranteed to fail some of the time.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
The problem with the WMF (Windows Metafile) file format turns out to be one of those careless things Microsoft did years ago with little or no consideration for the security consequences.
Almost all exploits you read about are buffer overflows of some kind, but not this one. WMF files are allowed to register a callback function, meaning that they are allowed to execute code, and this is what is being exploited in the WMF bug.
I find this mind-boggling to the point of absurdity. Regardless of any supposed benefit gained by this, allowing a data file to execute arbitrary code upon it being viewed is simply begging for an exploit like this. No matter whan spin Microsoft will try to put on this one, it makes them look bad. Extremely bad.
I hear there's rumors on the Slashdots
Good idea. But how do you "reactivate" this feature once a patch is released? I use Ifranview, but I also depend heavily on the thumbnail feature in explorer.
Sigh. I do wish people would offer some information with their click here/type-this instructions so people would understand WTF they're doing.To register (or re-register) the dll:To run the command, you can use a console window (cmd.exe), or the Run dialog box (accessible from the Start Menu).
Snort sigs have been available from BleedingSnort for some time now; I pushed them out to our corporate IDS yesterday morning.
(Warning, mangled by Slashcode - remove newlines)
t afile.pm.php; classtype:attempted-user; sid:2002734; rev:1;)
0 05/3086; sid:2002733; rev:1;)
#by mmlange alert tcp any any -> $HOME_NET any (msg:"BLEEDING-EDGE CURRENT WMF Exploit"; flow:established; content:"|01 00 09 00 00 03 52 1f 00 00 06 00 3d 00 00 00|"; content:"|00 26 06 0f 00 08 00 ff ff ff ff 01 00 00 00 03 00 00 00 00 00|"; reference: url,www.frsirt.com/exploits/20051228.ie_xp_pfv_me
# By Frank Knobbe, 2005-12-28 alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"BLEEDING-EDGE EXPLOIT WMF Escape Record Exploit"; flow:established,from_server; content:"|01 00 09 00 00 03|"; depth:500; content:"|00 00|"; distance:10; within:12; content:"|26 06 09 00|"; within:5000; classtype:attempted-user; reference:url,www.frsirt.com/english/advisories/2
Once again it looks like Microsoft are going to escape the 'perfect exploit' meltdown by the skin of their teeth. This is exploitable remotely, but Dr Evil can't sit at a console typing in arbitrary IP addresses to 0wn with the exploit. On the other hand you can get close to that sort of thing using Metasploit Framework.
"None are more hopelessly enslaved than those who falsely believe they are free." -- Goethe
Could someone please elaborate on whether using Firefox browser will help avoid this security hole.
And not only does the exploit work with .WMF (Windows MetaFile), but if the attacker renames it to, say, .JPG, Windows will detect this a really being a .WMF, and STILL execute it. Pretty serious stuff. See this bugtraq link for details.
640YB ought to be enough for anybody.
..to add a new mime-type definition to the Windows defaults..
Identifier: X-Application/WinTrojan
Name: Windows Trojan File
File Extension Pattern: *.wtf
~ Better a freak than a sheep. ~
Games should not be doing the kind of things that need Administrator privilege to do!
They have no business doing that, people without Admininstrator should be able to play, anything running as Administrator (or in that group) can do great damage (e.g. virus infections, file deletion, even destroy the BIOS), and doing things that require Administrator wrongly can also trash the system (accidently corrupting a DLL, locking up hardware, etc).
There is a RunAs on Windows, and it is useful for doing sys admin stuff only when needed. It would be nice if it could be configured that a browser run by Administrator (lets say to need to Google for a solution to a problem you are working on) would drop privs (but even Linux doesn't do that).
But my main point is games and other user programs should need Administrator.
Just because it CAN be done, doesn't mean it should!
It's the core security problem of Windows: the development culture doesn't respect security. Developers went for decades of DOS and Windows 3.1/9x without needing to worry about users and permissions. So they got used to assuming they could write whereever they wanted. When real user seperation and permissions became mainstream with Windows 2000 and XP, they weren't prepared to change. Because so much software required full access the easiest way to get stuff running is to run in an Administrator account. And since so many people (developers included) run as Administrator, why bother doing the right thing? Games are usually guilty, but there are piles of business and research software that is equally guilty. My brother is a sysadmin for a research lab. To keep Administrator access out of users hands, he has to bend of backwards to get the machines running the software his users need. A 2005 release of a $3,000 package that refuses to be placed in a directory with whitespace or a tilde, meaning it can't be installed in C:\Program Files. A $500 package that demands write access to a file in the C:\Windows directory.
This is one case where backward compatibility came at the expense of security. The development culture is moving too slowly. Bigger companies are starting to do the right thing and you get the occasional smaller development house following the rules. The killer is that huge mass of more specialized software. Apple bit the bullet when they cut over to Mac OS X; software had to do the right thing or it stopped working. Microsoft needs to make such a dramatic change or we'll be putting up with this bullshit for at least another five years.
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