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RE: EEYE: Microsoft ASN.1 Library Length Overflow Heap Corruption



>From the MS04-07 bulletin, Windows 9x is not mentioned. Someone has asked
whether Windows 98 is vulnerable to this attack or not. It could be that
Windows 98/ME are vulnerable to this attack through the installation of
Office suite.

The following link refers to the msasn1.dll on Windows ME. But, Windows ME
is not included in the security bulletin on Microsoft website. Then, the
question is whether Windows ME is vulnerable to this attack?
http://216.239.41.104/search?q=cache:bi0p-l5diJ4J:24.229.94.2/crypt32_import
s.html+ASN1BERDecOctetString&hl=en&ie=UTF-8

Below are a snapshot for usage of MSASN1.DLL. What a "monoculture
vulnerability" as far as the DLL base address is concerned!

========================
On Windows NT:
30 Module: 6af00000: C:\WINNT\System32\MSAsn1.DLL for E:\PROGRAM
FILES\MICROSOFT OFFICE\OFFICE\OUTLOOK.EXE

On Windows 2K:
 30 Module: 77430000: F:\WIN2K\system32\MSASN1.DLL for
\??\F:\WIN2K\SYSTEM32\WINLOGON.EXE
 58 Module: 77430000: F:\WIN2K\system32\MSASN1.DLL for
F:\WIN2K\SYSTEM32\SERVICES.EXE
 16 Module: 77430000: F:\WIN2K\system32\MSASN1.DLL for
F:\WIN2K\SYSTEM32\LSASS.EXE
 47 Module: 77430000: F:\WIN2K\system32\MSASN1.DLL for
F:\WIN2K\SYSTEM32\SPOOLSV.EXE
 56 Module: 77430000: f:\win2k\system32\MSASN1.DLL for
F:\WIN2K\SYSTEM32\SVCHOST.EXE
 40 Module: 77430000: F:\WIN2K\system32\MSASN1.DLL for
F:\PROGRA~1\MICROS~3\MSSQL\BINN\SQLSERVR.EXE
 26 Module: 77430000: F:\WIN2K\system32\MSASN1.DLL for
F:\WIN2K\SYSTEM32\INETSRV\INETINFO.EXE
 11 Module: 77430000: F:\WIN2K\System32\MSASN1.DLL for
F:\WIN2K\SYSTEM32\MQSVC.EXE

On Windows XP:
 11 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for
\??\C:\WINDOWS\SYSTEM32\WINLOGON.EXE
 15 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for
C:\WINDOWS\SYSTEM32\LSASS.EXE
 39 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for
C:\WINDOWS\SYSTEM32\SVCHOST.EXE
 20 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for
C:\WINDOWS\SYSTEM32\SVCHOST.EXE
 24 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for
C:\WINDOWS\SYSTEM32\SPOOLSV.EXE
 40 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for
C:\WINDOWS\EXPLORER.EXE
 34 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for C:\PROGRAM
FILES\MICROSOFT OFFICE\OFFICE\OUTLOOK.EXE
 29 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for C:\WINDOWS\HH.EXE
 67 Module: 762a0000: C:\WINDOWS\system32\MSASN1.dll for C:\PROGRAM
FILES\ADOBE\ACROBAT 4.0\ACROBAT\ACROBAT.EXE
========================

So, it seems that potential exploit of this vulnerability can be direct like
DCOM-RPC or through emails or even PDF files?

Peter Huang
http://www.ossecurity.ca/
MyDoom, YourDoom, are we all doomed?

> -----Original Message-----
> From: Marc Maiffret [mailto:mmaiffret@xxxxxxxx]
> Sent: Tuesday, February 10, 2004 3:47 PM
> To: Tina Bird
> Cc: Joe Blatz; BUGTRAQ@xxxxxxxxxxxxxxxxx
> Subject: RE: EEYE: Microsoft ASN.1 Library Length Overflow Heap
> Corruption
>
>
> Yes, I am not sure what Microsoft did with the wording there that seems
> to be misleading to at least a few people so far.