This story was publicised by 'Theartisan' a couple of weeks ago, but now Microsoft have published details and the software to fix the problem...

Heres the link to Microsoft... and official blurb

Microsoft's security flaw in all Windows products: Identity Spoofing!

Please update your product at:

http://www.microsoft.com/technet/tre...n/ms02-050.asp

(MAKE SURE YOU CUT AND PASTE THE ENTIRE LINK ABOVE)

Details: As of September 05, 2002
==========================================
Microsoft Security Bulletin MS02-050

Certificate Validation Flaw Could Enable Identity Spoofing (Q328145)
Originally posted: September 04, 2002

Summary
Who should read this bulletin: Customers using MicrosoftR WindowsR
Impact of vulnerability: Identity spoofing.
Maximum Severity Rating: Critical
Recommendation: Administrators should install the patch immediately.

Affected Software:
Microsoft Windows 98
Microsoft Windows 98 Second Edition
Microsoft Windows Me
Microsoft Windows NTR 4.0
Microsoft Windows NT 4.0, Terminal Server Edition
Microsoft Windows 2000
Microsoft Windows XP
Microsoft Office for Mac
Microsoft Internet Explorer for Mac
Microsoft Outlook Express for Mac