Microsoft has released twelve patches which fixes twenty vulnerabilities on their Windows operating system. Eleven of those patches are rated as critical and one of them is designed to patch the malware scanning engine which is used by various security softwares from Microsoft such as Windows OneCare and Windows Defender.

“The vulnerability is in the malware engine, which is part of Defender, which is part of Vista. So, yes, you can say that Vista [itself] is vulnerable,” said Mark Griesi who is the security program manager for the Microsoft Security Response Center.

Source: Computerworld