A new vulnerability in the Windows kernel was disclosed this Wednesday(11-24-2010) that could allow malware to attain administrative privileges by bypassing User Account Control (UAC).
A zero-day exploit in Microsoft Windows enables non-administrator accounts to execute code as if they were an administrator. The flaw appears to affect all versions of Windows back to at least Windows XP, including the latest Windows 2008 R2 and Windows 7 systems.
A bug in win32k.sys, which is part of the Windows kernel, seems to be responsible for this exploit. The flaw is related to the way in which a certain registry key is interpreted and enables an attacker to impersonate the system account, which has nearly unlimited access to all components of the Windows system. The registry key in question is under the full control of non-privileged users.
This exploit does not allow remote code execution (RCE). Thus, malicious code that uses the exploit needs to be introduced. So your anti-virus system should be able to block those payloads and keep you safe.
