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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."
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
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...
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?
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.
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
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.
What we have in the Linux and BSD world at least are very good Mandatory Access Control systems that help mitigate some of this risk. In the Linux world you can use SELinux (shudder) or use something even easier, AppArmor. If you properly profile an application to determine what it should and should not do you'll be in much better shape when new exploits like this come out. It won't save you from everything since they can still get access to anything the program could legitimately access in the first place but it's much more efficient than setting up sandboxes for everything like chroot and much more secure.
Never ever visit astalavista from windows, not even in Firefox - even using firefox, free-av catched ~10 viruses that tried to execute while only visiting the site, and searching for my lost cd key (well, lost CD to be precise, taht came with my TV card, with the only app that worked for me).
You can be infected whenever Windows uses its default image viewer to display certain image types. This means there is a long list of applications that are vulnerable that rely upon the image viewer code, but as far as I know no one has yet compiled that list. Windows uses this code when previewing images (for example). The current way this is being exploited is to tell your web browser to open an image (wmf and jpg that I have heard about) in the picture viewer. On IE, this behavior defaults to happening automatically. That means you go to a page and it installs whatever code it wants. With Firefox, you go to a page and a dialogue asks to open a .jpg or .wmf file. If you agree, it installs whatever, but if you decline you're in the clear.
1) Yes, Virtual PC and WINE allow you to run Microsoft programs like Internet Explorer and Office.
2) The vulnerability is in the Microsoft Windows Graphics Rendering Engine, which is a part of the Windows kernel, and is why the exploit affects Windows versions from Win98 to WinXP.
3) Virtual PC and WINE running under Linux do not use the Microsoft Graphics Rendering Engine.
4) Even if they did, a Windows program trying to run in a Linux environment is a fish out of water, and can't do much besides SEGFAULT and exit.
5) Therefore, Linux (and Mac) users are safe, even if they are running IE or Office - just like the article said.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
The real lesson is of course that once again mr buffer overflow strikes (don't implement anything in C if it needs to be secure). This time it's on windows.
This isn't a buffer overflow, its a design flaw that allows metafiles to register callbacks with GDI32. And I fail to see what language a programmer uses has anything to do with it. Bad programmers are bad programmers reguardless of the language used. To the CPU its all instructions, it doesn't care if its issued by the crt or the java_vm.
Enjoy,
It's just the normal noises in here.
The graphics rendering engine is divided between the Win32 subsystem which is a user process (csrss.exe), and the Win32 executive (Win32.sys) which actually runs in kernel space. The portion of the graphics system in the executive is limitted almost exclusively to the actual displaying of images and direct interaction with the drivers that interface with the display hardware. I'm not 100% sure, but I can't ever recall there being a vulnerability found in this part of the executive.
This specific vulnerability, like almost all image processing vulnerabilities, occurs in the image format parser, which is in the Win32 subsystem. As such its not in the kernel and runs in standard user scope. I know this doesn't change the point you were trying to make, which was the vulnerability doesn't occur on other systems. I just wanted to correct the statement about it being a kernel vulnerability.
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!
If there ever was a smoking-gun lead-pipe indictment of Microsoft's sloppy love of whizzo features, security, stability, maintainability, administerability be damned; this has GOT to be it. If the filetype API is that flawed, we need to just get rid of .WMF files, period.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill