[There's a reason that Yoda is the unofficial mascot of SBS.  Size indeed matters not.] Oh let's just rip out those dll's shall we? - THE OFFICIAL BLOG OF THE SBS "DIVA"

Oh let's just rip out those dll's shall we?

One of the suggestions I see on many of the Security sites are to unregister certain DLL's to ensure that this WMF vulnerability can't be exploited.  Now maybe it's just me...but unregistering DLLs that break image, thumbnails and what not... and especially if I have to worry about registering those files and sticking them back in seems to me a bit drastic.  To me the saner approach is to ...again...use our Risk Analysis view....

Which machines in my office are most at risk.... uh... honestly?  Mine.  But do give extra protection for all in the office...what's an easy protection mechanism that I can do on my network?

Steps I've already done...block files at the mail gateway ....block image types at the firewall.....

Okay so what else can I do on my machine.... Enable DEP protection for all programsViruslist says that DEP is marginally effective and doesn't work if you have image viewers like Irfanview.  Yo.  Folks.  Irfanview is a known image program in the forensic biz that can view ANYTHING.  I don't define it as the 'viewer of choice for many'.  Geeks maybe.  But my Mom and Dad?  No.

Do I have it on any other machine except for mine?  Nope.  Does it appear that enabling DEP for all programs is effective for mere mortals that have normal software at this time?  Yes.  Can DEP be enabled without major impact?  You bet your bippy.  Working just fine here and so I'm thinking...why the heck am I leaving it at the default?

P.S. Knowing my luck I'll probably find out that bippy means something obscene....

Published Thursday, December 29, 2005 5:09 PM by bradley
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Comments

# re: Oh let's just rip out those dll's shall we?

What the heck is a bippy?

Thursday, December 29, 2005 8:07 PM by Vlad Mazek

# re: Oh let's just rip out those dll's shall we?

once again...the diva brings it to the low point.

the phrase 'you bet your sweet bippy' was popularized on rowan & martin's groundbreaking variety show "laugh-in."

and, altho no formal definition exists for 'bippy'...the general consensus is that is it means 'you bet your sweet a**'

Thursday, December 29, 2005 11:27 PM by happyfunboy

# re: Oh let's just rip out those dll's shall we?

I think it's long past time, too, that graphics rendering programs (actually, any program that can open files of multiple types) refused to render a ".GIF" containing a WMF, or an ".MPG" containing an AVI, or a ".RTF" that contains a DOC file. Maybe give the information as to what type the file really is, so that a user can rename wrongly named files, but that way you would be able to do blocking on extension, and know that the ones that got through by pretending to be something else would stand a chance (however slight, given some users' desperate need to view naked dancing pigs) of being stopped at the desktop.

And, of course, people like thee and me would be made aware that we are looking at a potential incursion.

Friday, December 30, 2005 11:00 AM by Alun Jones

# Are you WMF'd to death yet?

Wondering why you haven't seen any feedback from me on the most recent 0-day exploit on Windows, which takes advantage of a vulnerability in the graphics rendering engine? I took a vacation away from the computer for a few days to catch up on some technical reading, and come back to a plethora of information that pretty much sums up anything I would say. In a blog post in the next few days, I will post just WHAT I was reading, as its pretty interesting. I'm shaking my head as I absorb some of this new stuff. Anyways, as a summary of the past few days where the world has been screaming that the sky is falling, here is the nitty gritty that matters (at least from my POV) Before you do anything, go read the Microsoft Security Advisory (MSA 912840) on the matter. According to guys over at Sunbelt, Microsoft may be incorrectly stating that software DEP will help mitigate against this threat. Seems that hardware DEP works, software DEP from Microsoft does not. No one has reported if some of the other software DEP agents defend against this attack or not. Susan has a great post on how to filter out WMF attachments on Exchange. Jesper has an excellent post on how to block certain extensions with ISA. Even when he goes on holidays he has time to play with ISA :) The easiest fix (temporarily) is to unregister the vulnerable code, using "REGSVR32 /U SHIMGVW.DLL" (without the quotes of course) from Start->Run I disagree with Susan that it is too drastic to unregister the DLL. It's quite trival a fix to signficantly mitigate against this threat without impacting the rest of the system. So you don't get pretty thumbnails. But you do prevent the exploit through this attack vector (I will point out it won't stop against someone opening an exploited WMF in MS Paint etc). And with the ability to push this out to all the desktops pretty quickly with a script... it takes no time to toggle it on/off. YMMV of course. That's pretty much all you will hear from me on the WMF issue for now. You can read the other 1,000,000 blog posts about it for more information....

Friday, December 30, 2005 5:52 PM by Dana Epp's ramblings at the Sanctuary

# re: Oh let's just rip out those dll's shall we?

Hey Bradley,

Thank you for the reference to my Blog. I spent a lot of time researching this new exploit and I've had enough. As Dana points out it's the focus of a million Blog's now and has been beaten to death.

I did create one last entry to explain why many of us recommend a drastic step like unregistering a system DLL.

http://billpstudios.blogspot.com/2005/12/why-is-0-day-wmf-exploit-such-big-deal.html

One of the reasons I mention is,

"An example of the programming code that allows this hack has been widely distributed and is still available online. That means a twelve year old with some computer skills can replicate his own version..."

Glad I found your Blog,
BillP

Saturday, December 31, 2005 9:53 PM by Bill Pytlovany