WMF Exploit!!! Install this patch now!

[Jim]

In case you have been living under a rock for the last week or so, you may
not have heard about the WMF Windows exploit.

For those rock dwellers, here's the scoop.....short and sweet. Reprinted
here without permission from SANS at
http://isc.sans.org/diary.php?storyid=994. Hope they don't mind.... .

---------------------------------------------

WMF FAQ (NEW)
Published: 2006-01-03,
Last Updated: 2006-01-03 08:55:06 UTC by Johannes Ullrich (Version: 3(click
to highlight changes))

[a few users offered translations of this FAQ into various languages.
Obviously, we can not check the translation for accuracy, nor can we update
them. So use at your own risk: Deutsch and Deutsch (pdf), Catalan , Español
, Italiana and Italiana, Polski, Suomenkielinen, Danish, Japanese,
Slovenian, Chinese, Norwegian and Nederlands (in progress) ]


a.. Why is this issue so important?
The WMF vulnerability uses images (WMF images) to execute arbitrary code. It
will execute just by viewing the image. In most cases, you don't have click
anything. Even images stored on your system may cause the exploit to be
triggered if it is indexed by some indexing software. Viewing a directory in
Explorer with 'Icon size' images will cause the exploit to be triggered as
well.

a.. Is it better to use Firefox or Internet Explorer?
Internet Explorer will view the image and trigger the exploit without
warning. New versions of Firefox will prompt you before opening the image.
However, in most environments this offers little protection given that these
are images and are thus considered 'safe'.

a.. What versions of Windows are affected?
All. Windows 2000, Windows XP, (SP1 and SP2), Windows 2003. All are affected
to some extent. Mac OS-X, Unix or BSD is not affected.

Note: If you're still running on Win98/ME, this is a watershed moment: we
believe (untested) that your system is vulnerable and there will be no patch
from MS. Your mitigation options are very limited. You really need to
upgrade.

a.. What can I do to protect myself?
1.. Microsoft has not yet released a patch. An unofficial patch was made
available by Ilfak Guilfanov. Our own Tom Liston reviewed the patch and we
tested it. The reviewed and tested version is available here (now at v1.4,
MD5: 15f0a36ea33f39c1bcf5a98e51d4f4f6), PGP signature (signed with ISC key)
here. THANKS to Ilfak Guilfanov for providing the patch!!
2.. You can unregister the related DLL.
3.. Virus checkers provide some protection.
To unregister the DLL:

a.. Click Start, click Run, type "regsvr32 -u %windir%system32shimgvw.dll"
(without the quotation marks... our editor keeps swallowing the
backslashes... its %windir%(backslash)system32(backslash)shimgvw.dll), and
then click OK.
b.. A dialog box appears to confirm that the un-registration process has
succeeded. Click OK to close the dialog box.
Our current "best practice" recommendation is to both unregister the DLL and
to use the unofficial patch.

a.. How does the unofficial patch work?
The wmfhotfix.dll is injected into any process loading user32.dll. The DLL
then patches (in memory) gdi32.dll's Escape() function so that it ignores
any call using the SETABORTPROC (ie. 0x09) parameter. This should allow
Windows programs to display WMF files normally while still blocking the
exploit. The version of the patch located here has been carefully checked
against the source code provided as well as tested against all known
versions of the exploit. It should work on WinXP (SP1 and SP2) and Win2K.

a.. Will unregistering the DLL (without using the unofficial patch)
protect me?
It might help. But it is not foolproof. We want to be very clear on this: we
have some very stong indications that simply unregistering the shimgvw.dll
isn't always successful. The .dll can be re-registered by malicious
processes or other installations, and there may be issues where
re-registering the .dll on a running system that has had an exploit run
against it allowing the exploit to succeed. In addition it might be
possible for there to be other avenues of attack against the Escape()
function in gdi32.dll. Until there is a patch available from MS, we
recommend using the unofficial patch in addition to un-registering
shimgvw.dll.
a.. Should I just delete the DLL?
It might not be a bad idea, but Windows File Protection will probably
replace it. You'll need to turn off Windows File Protection first. Also,
once an official patch is available you'll need to replace the DLL.
(renaming, rather than deleting is probably better so it will still be
handy).

a.. Should I just block all .WMF images?
This may help, but it is not sufficient. WMF files are recognized by a
special header and the extension is not needed. The files could arrive using
any extension, or embeded in Word or other documents.

a.. What is DEP (Data Execution Protection) and how does it help me?
With Windows XP SP2, Microsoft introduced DEP. It protects against a wide
range of exploits, by preventing the execution of 'data segements'. However,
to work well, it requires hardware support. Some CPUs, like AMD's 64 Bit
CPUs, will provide full DEP protection and will prevent the exploit.

a.. How good are Anti Virus products to prevent the exploit?
At this point, we are aware of versions of the exploit that will not be
detected by antivirus engines. We hope they will catch up soon. But it will
be a hard battle to catch all versions of the exploit. Up to date AV systems
are necessary but likely not sufficient.

a.. How could a malicious WMF file enter my system?
There are too many methods to mention them all. E-mail attachments, web
sites, instant messaging are probably the most likely sources. Don't forget
P2P file sharing and other sources.

a.. Is it sufficient to tell my users not to visit untrusted web sites?
No. It helps, but its likely not sufficient. We had at least one widely
trusted web site (knoppix-std.org) which was compromissed. As part of the
compromise, a frame was added to the site redirecting users to a corrupt WMF
file. "Tursted" sites have been used like this in the past.

a.. What is the actual problem with WMF images here?
WMF images are a bit different then most other images. Instead of just
containing simple 'this pixel has that color' information, WMF images can
call external procedures. One of these procedure calls can be used to
execute the code.

a.. Should I use something like "dropmyrights" to lower the impact of an
exploit.
By all means yes. Also, do not run as an administrator level users for every
day work. However, this will only limit the impact of the exploit, and not
prevent it. Also: Web browsing is only one way to trigger the exploit. If
the image is left behind on your system, and later viewed by an
administrator, you may get 'hit'.

a.. Are my servers vulnerable?
Maybe... do you allow the uploading of images? email? Are these images
indexed? Do you sometimes use a web browser on the server? In short: If
someone can get a image to your server, and if the vulnerable DLL may look
at it, your server may very well be vulnerable.

a.. What can I do at my perimeter / firewall to protect my network?
Not much. A proxy server that strips all images from web sites? Probably
wont go over well with your users. At least block .WMF images (see above
about extensions...). If your proxy has some kind of virus checker, it may
catch it. Same for mail servers. The less you allow your users to initiate
outbound connections, the better. Close monitoring of user workstations may
provide a hint if a work station is infected.

a.. Can I use an IDS to detect the exploit?
Most IDS vendors are working on signatures. Contact your vendor for details.
Bleedingsnort.org is providing some continuosly improving signatures for
snort users.

a.. If I get hit by the exploit, what can I do?
Not much :-(. It very much depends on the exact exploit you are hit with.
Most of them will download additional components. It can be very hard, or
even impossible, to find all the pieces. Microsoft offers free support for
issues like that at 866-727-2389 (866 PC SAFETY).

a.. Does Microsoft have information available?
http://www.microsoft.com/technet/security/advisory/912840.mspx
But there is no patch at the time of this writing.


a.. What does CERT have to say?
http://www.kb.cert.org/vuls/id/181038
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-4560

 

[Jim]

Direct link to patch......
http://handlers.sans.org/tliston/wmffix_hexblog14.exe

 

[Tom [Pepper] Willett]

MS has updated their security advisory to indicate the patch is expected to
be released on the next patch Tuesday, Jan 10th.
http://www.microsoft.com/technet/security/advisory/912840.mspx

Tom
| In case you have been living under a rock for the last week or so, you may
| not have heard about the WMF Windows exploit.
|
| For those rock dwellers, here's the scoop.....short and sweet. Reprinted
| here without permission from SANS at
| http://isc.sans.org/diary.php?storyid=994. Hope they don't mind.... .
|
| ---------------------------------------------
|
| WMF FAQ (NEW)
| Published: 2006-01-03,
| Last Updated: 2006-01-03 08:55:06 UTC by Johannes Ullrich (Version:
3(click
| to highlight changes))
|
| [a few users offered translations of this FAQ into various languages.
| Obviously, we can not check the translation for accuracy, nor can we
update
| them. So use at your own risk: Deutsch and Deutsch (pdf), Catalan ,
Español
| , Italiana and Italiana, Polski, Suomenkielinen, Danish, Japanese,
| Slovenian, Chinese, Norwegian and Nederlands (in progress) ]
|
|
| a.. Why is this issue so important?
| The WMF vulnerability uses images (WMF images) to execute arbitrary code.
It
| will execute just by viewing the image. In most cases, you don't have
click
| anything. Even images stored on your system may cause the exploit to be
| triggered if it is indexed by some indexing software. Viewing a directory
in
| Explorer with 'Icon size' images will cause the exploit to be triggered as
| well.
|
| a.. Is it better to use Firefox or Internet Explorer?
| Internet Explorer will view the image and trigger the exploit without
| warning. New versions of Firefox will prompt you before opening the image.
| However, in most environments this offers little protection given that
these
| are images and are thus considered 'safe'.
|
| a.. What versions of Windows are affected?
| All. Windows 2000, Windows XP, (SP1 and SP2), Windows 2003. All are
affected
| to some extent. Mac OS-X, Unix or BSD is not affected.
|
| Note: If you're still running on Win98/ME, this is a watershed moment: we
| believe (untested) that your system is vulnerable and there will be no
patch
| from MS. Your mitigation options are very limited. You really need to
| upgrade.
|
| a.. What can I do to protect myself?
| 1.. Microsoft has not yet released a patch. An unofficial patch was made
| available by Ilfak Guilfanov. Our own Tom Liston reviewed the patch and we
| tested it. The reviewed and tested version is available here (now at v1.4,
| MD5: 15f0a36ea33f39c1bcf5a98e51d4f4f6), PGP signature (signed with ISC
key)
| here. THANKS to Ilfak Guilfanov for providing the patch!!
| 2.. You can unregister the related DLL.
| 3.. Virus checkers provide some protection.
| To unregister the DLL:
|
| a.. Click Start, click Run, type "regsvr32 -u
%windir%system32shimgvw.dll"
| (without the quotation marks... our editor keeps swallowing the
| backslashes... its %windir%(backslash)system32(backslash)shimgvw.dll), and
| then click OK.
| b.. A dialog box appears to confirm that the un-registration process has
| succeeded. Click OK to close the dialog box.
| Our current "best practice" recommendation is to both unregister the DLL
and
| to use the unofficial patch.
|
| a.. How does the unofficial patch work?
| The wmfhotfix.dll is injected into any process loading user32.dll. The
DLL
| then patches (in memory) gdi32.dll's Escape() function so that it ignores
| any call using the SETABORTPROC (ie. 0x09) parameter. This should allow
| Windows programs to display WMF files normally while still blocking the
| exploit. The version of the patch located here has been carefully checked
| against the source code provided as well as tested against all known
| versions of the exploit. It should work on WinXP (SP1 and SP2) and Win2K.
|
| a.. Will unregistering the DLL (without using the unofficial patch)
| protect me?
| It might help. But it is not foolproof. We want to be very clear on this:
we
| have some very stong indications that simply unregistering the shimgvw.dll
| isn't always successful. The .dll can be re-registered by malicious
| processes or other installations, and there may be issues where
| re-registering the .dll on a running system that has had an exploit run
| against it allowing the exploit to succeed. In addition it might be
| possible for there to be other avenues of attack against the Escape()
| function in gdi32.dll. Until there is a patch available from MS, we
| recommend using the unofficial patch in addition to un-registering
| shimgvw.dll.
| a.. Should I just delete the DLL?
| It might not be a bad idea, but Windows File Protection will probably
| replace it. You'll need to turn off Windows File Protection first. Also,
| once an official patch is available you'll need to replace the DLL.
| (renaming, rather than deleting is probably better so it will still be
| handy).
|
| a.. Should I just block all .WMF images?
| This may help, but it is not sufficient. WMF files are recognized by a
| special header and the extension is not needed. The files could arrive
using
| any extension, or embeded in Word or other documents.
|
| a.. What is DEP (Data Execution Protection) and how does it help me?
| With Windows XP SP2, Microsoft introduced DEP. It protects against a wide
| range of exploits, by preventing the execution of 'data segements'.
However,
| to work well, it requires hardware support. Some CPUs, like AMD's 64 Bit
| CPUs, will provide full DEP protection and will prevent the exploit.
|
| a.. How good are Anti Virus products to prevent the exploit?
| At this point, we are aware of versions of the exploit that will not be
| detected by antivirus engines. We hope they will catch up soon. But it
will
| be a hard battle to catch all versions of the exploit. Up to date AV
systems
| are necessary but likely not sufficient.
|
| a.. How could a malicious WMF file enter my system?
| There are too many methods to mention them all. E-mail attachments, web
| sites, instant messaging are probably the most likely sources. Don't
forget
| P2P file sharing and other sources.
|
| a.. Is it sufficient to tell my users not to visit untrusted web sites?
| No. It helps, but its likely not sufficient. We had at least one widely
| trusted web site (knoppix-std.org) which was compromissed. As part of the
| compromise, a frame was added to the site redirecting users to a corrupt
WMF
| file. "Tursted" sites have been used like this in the past.
|
| a.. What is the actual problem with WMF images here?
| WMF images are a bit different then most other images. Instead of just
| containing simple 'this pixel has that color' information, WMF images can
| call external procedures. One of these procedure calls can be used to
| execute the code.
|
| a.. Should I use something like "dropmyrights" to lower the impact of an
| exploit.
| By all means yes. Also, do not run as an administrator level users for
every
| day work. However, this will only limit the impact of the exploit, and not
| prevent it. Also: Web browsing is only one way to trigger the exploit. If
| the image is left behind on your system, and later viewed by an
| administrator, you may get 'hit'.
|
| a.. Are my servers vulnerable?
| Maybe... do you allow the uploading of images? email? Are these images
| indexed? Do you sometimes use a web browser on the server? In short: If
| someone can get a image to your server, and if the vulnerable DLL may look
| at it, your server may very well be vulnerable.
|
| a.. What can I do at my perimeter / firewall to protect my network?
| Not much. A proxy server that strips all images from web sites? Probably
| wont go over well with your users. At least block .WMF images (see above
| about extensions...). If your proxy has some kind of virus checker, it may
| catch it. Same for mail servers. The less you allow your users to initiate
| outbound connections, the better. Close monitoring of user workstations
may
| provide a hint if a work station is infected.
|
| a.. Can I use an IDS to detect the exploit?
| Most IDS vendors are working on signatures. Contact your vendor for
details.
| Bleedingsnort.org is providing some continuosly improving signatures for
| snort users.
|
| a.. If I get hit by the exploit, what can I do?
| Not much :-(. It very much depends on the exact exploit you are hit with.
| Most of them will download additional components. It can be very hard, or
| even impossible, to find all the pieces. Microsoft offers free support for
| issues like that at 866-727-2389 (866 PC SAFETY).
|
| a.. Does Microsoft have information available?
| http://www.microsoft.com/technet/security/advisory/912840.mspx
| But there is no patch at the time of this writing.
|
|
| a.. What does CERT have to say?
| http://www.kb.cert.org/vuls/id/181038
| http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-4560
|
|
| -----------------------------------------
|
| So run the patch, reboot and keep your fingers crossed!
|
| Jim
|
|

 

[Jim]

Thanks for the update.....meanwhile, run the patch on the SANS site or
you're open to anything.

Direct link to patch......
http://handlers.sans.org/tliston/wmffix_hexblog14.exe

Jim

MS has updated their security advisory to indicate the patch is expected
to
be released on the next patch Tuesday, Jan 10th.
http://www.microsoft.com/technet/security/advisory/912840.mspx

Tom
| In case you have been living under a rock for the last week or so, you
may
| not have heard about the WMF Windows exploit.
|
| For those rock dwellers, here's the scoop.....short and sweet.
Reprinted
| here without permission from SANS at
| http://isc.sans.org/diary.php?storyid=994. Hope they don't mind.... .
|
| ---------------------------------------------
|
| WMF FAQ (NEW)
| Published: 2006-01-03,
| Last Updated: 2006-01-03 08:55:06 UTC by Johannes Ullrich (Version:
3(click
| to highlight changes))
|
| [a few users offered translations of this FAQ into various languages.
| Obviously, we can not check the translation for accuracy, nor can we
update
| them. So use at your own risk: Deutsch and Deutsch (pdf), Catalan ,
Español
| , Italiana and Italiana, Polski, Suomenkielinen, Danish, Japanese,
| Slovenian, Chinese, Norwegian and Nederlands (in progress) ]
|
|
| a.. Why is this issue so important?
| The WMF vulnerability uses images (WMF images) to execute arbitrary
code.
It
| will execute just by viewing the image. In most cases, you don't have
click
| anything. Even images stored on your system may cause the exploit to be
| triggered if it is indexed by some indexing software. Viewing a
directory
in
| Explorer with 'Icon size' images will cause the exploit to be triggered
as
| well.
|
| a.. Is it better to use Firefox or Internet Explorer?
| Internet Explorer will view the image and trigger the exploit without
| warning. New versions of Firefox will prompt you before opening the
image.
| However, in most environments this offers little protection given that
these
| are images and are thus considered 'safe'.
|
| a.. What versions of Windows are affected?
| All. Windows 2000, Windows XP, (SP1 and SP2), Windows 2003. All are
affected
| to some extent. Mac OS-X, Unix or BSD is not affected.
|
| Note: If you're still running on Win98/ME, this is a watershed moment:
we
| believe (untested) that your system is vulnerable and there will be no
patch
| from MS. Your mitigation options are very limited. You really need to
| upgrade.
|
| a.. What can I do to protect myself?
| 1.. Microsoft has not yet released a patch. An unofficial patch was
made
| available by Ilfak Guilfanov. Our own Tom Liston reviewed the patch and
we
| tested it. The reviewed and tested version is available here (now at
v1.4,
| MD5: 15f0a36ea33f39c1bcf5a98e51d4f4f6), PGP signature (signed with ISC
key)
| here. THANKS to Ilfak Guilfanov for providing the patch!!
| 2.. You can unregister the related DLL.
| 3.. Virus checkers provide some protection.
| To unregister the DLL:
|
| a.. Click Start, click Run, type "regsvr32 -u
%windir%system32shimgvw.dll"
| (without the quotation marks... our editor keeps swallowing the
| backslashes... its %windir%(backslash)system32(backslash)shimgvw.dll),
and
| then click OK.
| b.. A dialog box appears to confirm that the un-registration process
has
| succeeded. Click OK to close the dialog box.
| Our current "best practice" recommendation is to both unregister the DLL
and
| to use the unofficial patch.
|
| a.. How does the unofficial patch work?
| The wmfhotfix.dll is injected into any process loading user32.dll. The
DLL
| then patches (in memory) gdi32.dll's Escape() function so that it
ignores
| any call using the SETABORTPROC (ie. 0x09) parameter. This should allow
| Windows programs to display WMF files normally while still blocking the
| exploit. The version of the patch located here has been carefully
checked
| against the source code provided as well as tested against all known
| versions of the exploit. It should work on WinXP (SP1 and SP2) and
Win2K.
|
| a.. Will unregistering the DLL (without using the unofficial patch)
| protect me?
| It might help. But it is not foolproof. We want to be very clear on
this:
we
| have some very stong indications that simply unregistering the
shimgvw.dll
| isn't always successful. The .dll can be re-registered by malicious
| processes or other installations, and there may be issues where
| re-registering the .dll on a running system that has had an exploit run
| against it allowing the exploit to succeed. In addition it might be
| possible for there to be other avenues of attack against the Escape()
| function in gdi32.dll. Until there is a patch available from MS, we
| recommend using the unofficial patch in addition to un-registering
| shimgvw.dll.
| a.. Should I just delete the DLL?
| It might not be a bad idea, but Windows File Protection will probably
| replace it. You'll need to turn off Windows File Protection first. Also,
| once an official patch is available you'll need to replace the DLL.
| (renaming, rather than deleting is probably better so it will still be
| handy).
|
| a.. Should I just block all .WMF images?
| This may help, but it is not sufficient. WMF files are recognized by a
| special header and the extension is not needed. The files could arrive
using
| any extension, or embeded in Word or other documents.
|
| a.. What is DEP (Data Execution Protection) and how does it help me?
| With Windows XP SP2, Microsoft introduced DEP. It protects against a
wide
| range of exploits, by preventing the execution of 'data segements'.
However,
| to work well, it requires hardware support. Some CPUs, like AMD's 64 Bit
| CPUs, will provide full DEP protection and will prevent the exploit.
|
| a.. How good are Anti Virus products to prevent the exploit?
| At this point, we are aware of versions of the exploit that will not be
| detected by antivirus engines. We hope they will catch up soon. But it
will
| be a hard battle to catch all versions of the exploit. Up to date AV
systems
| are necessary but likely not sufficient.
|
| a.. How could a malicious WMF file enter my system?
| There are too many methods to mention them all. E-mail attachments, web
| sites, instant messaging are probably the most likely sources. Don't
forget
| P2P file sharing and other sources.
|
| a.. Is it sufficient to tell my users not to visit untrusted web sites?
| No. It helps, but its likely not sufficient. We had at least one widely
| trusted web site (knoppix-std.org) which was compromissed. As part of
the
| compromise, a frame was added to the site redirecting users to a corrupt
WMF
| file. "Tursted" sites have been used like this in the past.
|
| a.. What is the actual problem with WMF images here?
| WMF images are a bit different then most other images. Instead of just
| containing simple 'this pixel has that color' information, WMF images
can
| call external procedures. One of these procedure calls can be used to
| execute the code.
|
| a.. Should I use something like "dropmyrights" to lower the impact of
an
| exploit.
| By all means yes. Also, do not run as an administrator level users for
every
| day work. However, this will only limit the impact of the exploit, and
not
| prevent it. Also: Web browsing is only one way to trigger the exploit.
If
| the image is left behind on your system, and later viewed by an
| administrator, you may get 'hit'.
|
| a.. Are my servers vulnerable?
| Maybe... do you allow the uploading of images? email? Are these images
| indexed? Do you sometimes use a web browser on the server? In short: If
| someone can get a image to your server, and if the vulnerable DLL may
look
| at it, your server may very well be vulnerable.
|
| a.. What can I do at my perimeter / firewall to protect my network?
| Not much. A proxy server that strips all images from web sites? Probably
| wont go over well with your users. At least block .WMF images (see
above
| about extensions...). If your proxy has some kind of virus checker, it
may
| catch it. Same for mail servers. The less you allow your users to
initiate
| outbound connections, the better. Close monitoring of user workstations
may
| provide a hint if a work station is infected.
|
| a.. Can I use an IDS to detect the exploit?
| Most IDS vendors are working on signatures. Contact your vendor for
details.
| Bleedingsnort.org is providing some continuosly improving signatures for
| snort users.
|
| a.. If I get hit by the exploit, what can I do?
| Not much :-(. It very much depends on the exact exploit you are hit
with.
| Most of them will download additional components. It can be very hard,
or
| even impossible, to find all the pieces. Microsoft offers free support
for
| issues like that at 866-727-2389 (866 PC SAFETY).
|
| a.. Does Microsoft have information available?
| http://www.microsoft.com/technet/security/advisory/912840.mspx
| But there is no patch at the time of this writing.
|
|
| a.. What does CERT have to say?
| http://www.kb.cert.org/vuls/id/181038
| http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-4560
|
|
| -----------------------------------------
|
| So run the patch, reboot and keep your fingers crossed!
|
| Jim
|
|

 

[Chris H.]

Microsoft has not released a patch at this point. Please do not download or
install a patch from any other source.
--
Chris H.
Microsoft Windows MVP/Tablet PC
Tablet Creations - http://nicecreations.us/
Associate Expert
Expert Zone -

 

[Jim]

Chris,

You are acting in an extremely irresponsible manner. This is one of the
largest exploits ever to hit the Windows platform (in number of machines
affected), and you are telling people to do nothing.

The only thing more irresponsible than your post is Microsoft's refusal
to take immediate action for such an exploit.

Jim

 

[Richard Urban]

The patch works fine. I have installed it on my three computers without any
problem. Even if it caused a couple of glitches, it is better than having
your computer taken over, and controlled, by an unknown individual.

--


Regards,

Richard Urban
Microsoft MVP Windows Shell/User

Quote from George Ankner:
If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!

 

[Tom Porterfield]

Chris,

You are acting in an extremely irresponsible manner. This is one of the
largest exploits ever to hit the Windows platform (in number of machines
affected), and you are telling people to do nothing.

The only thing more irresponsible than your post is Microsoft's refusal
to take immediate action for such an exploit.

Microsoft is taking action. They have posted an advisory which includes
steps that can be taken to decrease the likelihood of a system falling
prey to this vulnerability. A patch has been developed by MS and is now
in the process of being validated to insure that it meets their release
standards. The MS patch has a tentative release date of January 10,
2006, one week from today.

As most AV vendors now guard against any attack of this vulnerability,
keeping your AV signatures up to date will keep you protected. If,
after gathering all information on this you feel you are still at risk,
then installing the patch available on the SANS website will add
additional protection. Understand though that the SANS patch has not
gone through the same level of testing that the MS patch will have gone
through so has the potential of causing problems.

In the past, files have been offered as patches to vulnerabilities that
were themselves an exploit of some sort. It is always best to be wary
of patches from any non-verifiable source.
--
Tom Porterfield
MS-MVP Windows
http://support.teloep.org

Please post all follow-ups to the newsgroup only.

 

[Chris H.]

Incorrect, Jim. Users should wait for the official patch, and not risk (1)
going to some web site not connected with Microsoft, and (2) not installing
some "patch" or other software on their machine from an unknown source.

As noted in the security bulletin issued, there are specific instances where
this violation of a computer can take place, and they include being lured to
a web site.

Protection of the computer will come with intelligent computer usage,
including not visiting an unknown site for a "fix" not coming directly from
Microsoft.
--
Chris H.
Microsoft Windows MVP/Tablet PC
Tablet Creations - http://nicecreations.us/
Associate Expert
Expert Zone -

 

[Jim]

Microsoft is taking action. They have posted an advisory which includes
steps that can be taken to decrease the likelihood of a system falling
prey to this vulnerability. A patch has been developed by MS and is now
in the process of being validated to insure that it meets their release
standards. The MS patch has a tentative release date of January 10, 2006,
one week from today.

One week is a very long time with an exploit like this circulating. Not
only can the exploit be used to take over your PC and execute virtually any
code that the attacker wants....the exploit is so simple that any script
kiddie can do it - and lots of them are.

From Symantec's website.... "It has been reported that the following Web
sites may contain malicious files that trigger the exploit:


a.. [http://]h0nest.org/[REMOVED]/12.exe (IP address 195.0.210.192)
a.. [http://]kube.isa-geek.com/[REMOVED]/wen/up.exe (IP address not found)
a.. [http://]charmedmadgic.free.fr/[REMOVED]/sdbot05b.jpg (IP address
212.27.63.117)
a.. [http://]69.50.171.122/[REMOVED]/test1.php
a.. [http://]www.jerrynews.com/[REMOVED]/calc.exe (IP address
211.100.26.169)
a.. [http://]apperception.biz/[REMOVED]/main.exe (IP address 66.226.64.19)
a.. [http://]apperception.biz/[REMOVED]/calc.exe (IP address 66.226.64.19)
a.. [http://]sploso.com/[REMOVED]/starter2.exe (IP address 72.5.54.36)
a.. [ftp://]x.www2.ninoa.com/[REMOVED]/pub/ied.exe (IP address
205.177.28.180)
a.. [ftp://]x.www2.ninoa.com/[REMOVED]/pub/epl.exe (IP address
205.177.28.180)
a.. [http://]www.freecat.biz/[REMOVED]/tr/pawn005.exe (IP address not found)
a.. [http://]fullchain.net/[REMOVED]/apa/dex.exe (IP address
192.225.177.21)"

As most AV vendors now guard against any attack of this vulnerability,
keeping your AV signatures up to date will keep you protected. If, after
gathering all information on this you feel you are still at risk, then
installing the patch available on the SANS website will add additional
protection. Understand though that the SANS patch has not gone through
the same level of testing that the MS patch will have gone through so has
the potential of causing problems.

I'd rather be safe than sorry. Some Antivirus products have been updated to
catch the 2 variants that have appeared at first. But, as I am sure that
you are aware, variants of exploits rarely stop at 2 code variants.

In the past, files have been offered as patches to vulnerabilities that
were themselves an exploit of some sort. It is always best to be wary of
patches from any non-verifiable source.

Users should always be wary of executing ANY code on thier systems. Only
run code from trusted sources. That is why I gave the SANS link instead of
my company website. SANS is more widely known and has a history of
trustworthiness that a small company like mine has yet to attain.

While I understand your sketicism and applaude your watchful eye for any
code that will run on your system. We should also take any means nec. to
ensure the protection of the masses.

More people than you think do not have up-to-date antivirus protection.
This is not to say that this tool in any way negates the need for such
protection. Rather it is a stop-gap measure that will offer a measure of
protection, to those willing to take advantage of it, until Microsoft is
comfortable releasing thier patch.

Thanks for your feedback.

Jim

 

[Josh Einstein]

This is a typical response from Chris who only trusts MS's word as gospel.
But rather than linking directly to the EXE you should link to the page
where the user can download it. Direct EXE links are irresponsible to click
as well. Especially considering that they are so easily spoofed.

 

[Kerry Brown]

Incorrect, Jim. Users should wait for the official patch, and not
risk (1) going to some web site not connected with Microsoft, and (2)
not installing some "patch" or other software on their machine from
an unknown source.
As noted in the security bulletin issued, there are specific
instances where this violation of a computer can take place, and they
include being lured to a web site.

Protection of the computer will come with intelligent computer usage,
including not visiting an unknown site for a "fix" not coming
directly from Microsoft.

If you believe the security bulletin you are have obviously not seen this
exploit in action. Build a test machine, fully update Windows, install your
antivirus and antispyware apps of choice and go to one of the many known
sites that use this exploit. The machine will be infected, no if, ands, or
buts. The people using the exploit are changing it often enough that the
antivirus/spyware/malware apps can't keep up. I have tried it. have you? It
was scary. I immediately ran the unofficial patch on my own machines. By the
way many sites you think may be safe are not, knoppix-std dot org is one
site that was known to be hacked and was distributing malware via this
exploit. To most this would certainly seem to be a safe site. Many on these
newsgroups regularly recommend using knoppix.

Kerry

 

[Josh Einstein]

By the way, I got a patch at www.grc.com (another well known Windows
security expert) who links to Ilfak Guilfanov's temporary patch.

 

[Jim]

WMF info at
F-Secure...http://www.f-secure.com/weblog/archives/archive-122005.html#00000756...
and ...http://www.f-secure.com/weblog/archives/archive-012006.html#00000762
..

" MS Confirms WMF Flaw, Variants Spread Linked by Thom Holwerda on
2005-12-31 16:55:55 Microsoft acknowledged late Wednesday the existence of a
zero-day exploit for Windows Metafile images, and said it was looking into
ways to better protect its customers. Even worse, by the end of the day
nearly 50 variants of the exploit had already appeared. One security company
said the possibilities were endless on how the flaw could be exploited.
'This vulnerability can be used to install any type of malicious code, not
just Trojans and spyware, but also worms, bots or viruses that can cause
irreparable damage to computers,' said Luis Corrons of Panda Software." -
http://www.osnews.com/story.php?news_id=13136

Antivirus programs are not all detecting the new variants -
http://isc.sans.org/diary.php?storyid=998 .

It's up to you. If you think that your AV program will catch ALL variants
of a new exploit that can allow remote execution of code and remote control
of your personal or company PCs, by all means, float on.

On the other hand, if you cannot afford to take a chance with your personal
or company PCs and data, patch your systems by running
http://handlers.sans.org/tliston/wmffix_hexblog14.exe .

Your life.....your data.....your choice.

Jim

 

[Jim]

This is a typical response from Chris who only trusts MS's word as gospel.
But rather than linking directly to the EXE you should link to the page
where the user can download it. Direct EXE links are irresponsible to
click as well. Especially considering that they are so easily spoofed.

True enough.

More sites advise use of the unofficial patch.....
http://news.ft.com/cms/s/0d644d5e-7bb3-11da-ab8e-0000779e2340.html
http://www.f-secure.com/weblog/archives/archive-122005.html#00000756

Always get more than one source to verify the trustworthiness of any
download links......even mine.

Jim

 

[Chris H.]

Please speak for yourself only, Josh. This is a serious subject, and you
shouldn't be letting your personal opinions about people interfere with
guiding users in the right direction. It is irresponsible for anyone
download and install such an unknown, untested patch. Microsoft's security
bulletin, in part, already issued on the subject:
=====
Microsoft Security Advisory (912840)
Vulnerability in Graphics Rendering Engine Could Allow Remote Code
Execution.
Microsoft is investigating new public reports of a vulnerability in Windows.
Microsoft will continue to investigate the public reports to help provide
additional guidance for customers.
Microsoft is aware of detailed exploit code that could allow an attacker to
execute arbitrary code in the security context of the logged on user when
visiting a Web site, which contains a specially crafted Windows Metafile
(WMF) image. An attacker would have no way to force users to visit a
malicious Web site. Instead, an attacker would have to persuade them to
visit the Web site, typically by getting them to click a link that takes
them to the attacker's Web site.
Customers are encouraged to keep their antivirus software up to date. The
Microsoft Windows AntiSpyware (Beta) can also help protect your system from
spyware and other potentially unwanted software. We will continue to
investigate these public reports.
Upon completion of this investigation, Microsoft will take the appropriate
action to help protect our customers. This will include providing a security
update through our monthly release process or providing an out-of-cycle
security update, depending on customer needs.
Microsoft encourages users to exercise caution when they open e-mail and
links in e-mail from untrusted sources. For more information about Safe
Browsing, visit the Trustworthy Computing Web site.
We continue to encourage customers to follow our Protect Your PC guidance of
enabling a firewall, applying software updates and installing antivirus
software. Customers can learn more about these steps at the Protect Your PC
Web site.
Customers who believe they may have been affected by this issue can contact
Product Support Services. You can contact Product Support Services in the
United States and Canada at no charge using the PC Safety line (1
866-PCSAFETY). Customers outside of the United States and Canada can locate
the number for no-charge virus support by visiting the Microsoft Help and
Support Web site.
Mitigating Factors:
· In a Web-based attack scenario, an attacker would have to host a
Web site that contains a Web page that is used to exploit this
vulnerability. An attacker would have no way to force users to visit a
malicious Web site. Instead, an attacker would have to persuade them to
visit the Web site, typically by getting them to click a link that takes
them to the attacker's Web site.
· An attacker who successfully exploited this vulnerability could
gain the same user rights as the local user. Users whose accounts are
configured to have fewer user rights on the system could be less impacted
than users who operate with administrative user rights.
· By default, Internet Explorer on Windows Server 2003, on Windows
Server 2003 Service Pack 1, on Windows Server 2003 with Service Pack 1 for
Itanium-based Systems, and on Windows Server 2003 x64 Edition runs in a
restricted mode that is known as Enhanced Security Configuration This mode
mitigates this vulnerability where the e-mail vector is concerned although
clicking on a link would still put users at risk. In Windows Server 2003,
Microsoft Outlook Express uses plain text for reading and sending messages
by default. When replying to an e-mail message that is sent in another
format, the response is formatted in plain text. See the FAQ section of this
vulnerability for more information about Internet Explorer Enhanced Security
Configuration.
=====
--
Chris H.
Microsoft Windows MVP/Tablet PC
Tablet Creations - http://nicecreations.us/
Associate Expert
Expert Zone -

 

[Josh Einstein]

I'm just saying people should trust security experts. There *are* people out
there more qualified to give security guidance than you or MS. SANS,
F-secure, and Steve Gibson are 3 such parties.

The patch may be unknown to or untested by you, but not to those security
experts.

 

[Tom [Pepper] Willett]

I, for one, did my research and felt comfortable installing it on my home
pc, and all the computers on our company network.

Tom
| I'm just saying people should trust security experts. There *are* people
out
| there more qualified to give security guidance than you or MS. SANS,
| F-secure, and Steve Gibson are 3 such parties.
|
| The patch may be unknown to or untested by you, but not to those security
| experts.
|
| --
| Josh Einstein
| Tablet Enhancements for Outlook 2.0 - Try it free for 14 days
| www.tabletoutlook.com
|
| | > Please speak for yourself only, Josh. This is a serious subject, and
you
| > shouldn't be letting your personal opinions about people interfere with
| > guiding users in the right direction. It is irresponsible for anyone
| > download and install such an unknown, untested patch. Microsoft's
| > security bulletin, in part, already issued on the subject:
| > =====
| > Microsoft Security Advisory (912840)
| > Vulnerability in Graphics Rendering Engine Could Allow Remote Code
| > Execution.
| > Microsoft is investigating new public reports of a vulnerability in
| > Windows. Microsoft will continue to investigate the public reports to
help
| > provide additional guidance for customers.
| > Microsoft is aware of detailed exploit code that could allow an attacker
| > to execute arbitrary code in the security context of the logged on user
| > when visiting a Web site, which contains a specially crafted Windows
| > Metafile (WMF) image. An attacker would have no way to force users to
| > visit a malicious Web site. Instead, an attacker would have to persuade
| > them to visit the Web site, typically by getting them to click a link
that
| > takes them to the attacker's Web site.
| > Customers are encouraged to keep their antivirus software up to date.
The
| > Microsoft Windows AntiSpyware (Beta) can also help protect your system
| > from spyware and other potentially unwanted software. We will continue
to
| > investigate these public reports.
| > Upon completion of this investigation, Microsoft will take the
appropriate
| > action to help protect our customers. This will include providing a
| > security update through our monthly release process or providing an
| > out-of-cycle security update, depending on customer needs.
| > Microsoft encourages users to exercise caution when they open e-mail and
| > links in e-mail from untrusted sources. For more information about Safe
| > Browsing, visit the Trustworthy Computing Web site.
| > We continue to encourage customers to follow our Protect Your PC
guidance
| > of enabling a firewall, applying software updates and installing
antivirus
| > software. Customers can learn more about these steps at the Protect Your
| > PC Web site.
| > Customers who believe they may have been affected by this issue can
| > contact Product Support Services. You can contact Product Support
Services
| > in the United States and Canada at no charge using the PC Safety line (1
| > 866-PCSAFETY). Customers outside of the United States and Canada can
| > locate the number for no-charge virus support by visiting the Microsoft
| > Help and Support Web site.
| > Mitigating Factors:
| > · In a Web-based attack scenario, an attacker would have to
host
| > a Web site that contains a Web page that is used to exploit this
| > vulnerability. An attacker would have no way to force users to visit a
| > malicious Web site. Instead, an attacker would have to persuade them to
| > visit the Web site, typically by getting them to click a link that takes
| > them to the attacker's Web site.
| > · An attacker who successfully exploited this vulnerability
could
| > gain the same user rights as the local user. Users whose accounts are
| > configured to have fewer user rights on the system could be less
impacted
| > than users who operate with administrative user rights.
| > · By default, Internet Explorer on Windows Server 2003, on
| > Windows Server 2003 Service Pack 1, on Windows Server 2003 with Service
| > Pack 1 for Itanium-based Systems, and on Windows Server 2003 x64 Edition
| > runs in a restricted mode that is known as Enhanced Security
Configuration
| > This mode mitigates this vulnerability where the e-mail vector is
| > concerned although clicking on a link would still put users at risk. In
| > Windows Server 2003, Microsoft Outlook Express uses plain text for
reading
| > and sending messages by default. When replying to an e-mail message that
| > is sent in another format, the response is formatted in plain text. See
| > the FAQ section of this vulnerability for more information about
Internet
| > Explorer Enhanced Security Configuration.
| > =====
| > --
| > Chris H.
| > Microsoft Windows MVP/Tablet PC
| > Tablet Creations - http://nicecreations.us/
| > Associate Expert
| > Expert Zone -
| >
| > | >> This is a typical response from Chris who only trusts MS's word as
| >> gospel. But rather than linking directly to the EXE you should link to
| >> the page where the user can download it. Direct EXE links are
| >> irresponsible to click as well. Especially considering that they are so
| >> easily spoofed.
| >>
| >> --
| >> Josh Einstein
| >> Tablet Enhancements for Outlook 2.0 - Try it free for 14 days
| >> www.tabletoutlook.com
| >>
| >> | >>> Chris,
| >>>
| >>> You are acting in an extremely irresponsible manner. This is one
of
| >>> the largest exploits ever to hit the Windows platform (in number of
| >>> machines affected), and you are telling people to do nothing.
| >>>
| >>> The only thing more irresponsible than your post is Microsoft's
| >>> refusal to take immediate action for such an exploit.
| >>>
| >>> Jim
| >>>
| >>> | >>>> Microsoft has not released a patch at this point. Please do not
| >>>> download or install a patch from any other source.
| >>>> --
| >>>> Chris H.
| >>>> Microsoft Windows MVP/Tablet PC
| >>>> Tablet Creations - http://nicecreations.us/
| >>>> Associate Expert
| >>>> Expert Zone -
| >>>>
| >>>>
| >>>
| >>>
| >>
| >>
| >
| >
|
|

 

[Chris H.]

Yes, they should. How you can trust some sites which have claimed for more
than four years that Universal Plug and Play is going to "bring down the
Internet." ROFLOL! Yup, the Internet failed in 2001. Right.
--
Chris H.
Microsoft Windows MVP/Tablet PC
Tablet Creations - http://nicecreations.us/
Associate Expert
Expert Zone -

 

[Leythos]

I'm just saying people should trust security experts. There *are* people out
there more qualified to give security guidance than you or MS. SANS,
F-secure, and Steve Gibson are 3 such parties.

The patch may be unknown to or untested by you, but not to those security
experts.

Having a fully updated AV solution, blocking at the firewall for the
known attachments/http files, I'm not installing a third party patch. At
this time our AV product seems to catch it and the firewall blocks most
of them, so I'm going to leave the computers the way they are instead of
having to support a patch that I don't know how it impacts the entire
base of users computers.