Here we go again, the jolly guys at eEye have discovered a critical vulnerability affecting Windows 2000/XP/2003. There is a buffer overflow in Microsoft's ASN.1 library (MSASN1.DLL) that would allow an attacker to run code of his choice on the victim machine. As an interesting note, Microsoft have been sitting on this flaw since July 25th 2003 ! Here is the Microsoft bulletin. Better start patching before we see a new worm.
From the talk on bugtraq :
"If your running, Windows NT 4.0, Windows 2000, Windows XP, or Windows 2003, you are 99.9999% positive to be vulnerable, regardless of what your configuration might be. Don't try to guess if you have any of the affected protocols or applications (lets not forget third party apps using the MS ASN library), just install the patch. "
Microsoft ASN.1 Library Length Overflow Heap Corruption
Microsoft Internet Explorer
Microsoft Outlook Express
Third-party applications that use certificates
Microsoft IIS using SSL
NTLMv2 authentication (TCP/135, 139, 445)