Microsoft is warning users of a newly reported attack on one of its ActiveX browser components.

The company has received reports of a limited number of targeted attacks on a flaw in an ActiveX control for Snapshot Viewer, a browser plug-in for Microsoft Office Access 2000, 2002 and 2003. The flaw is not present in Office Access 2007.

If exploited, the vulnerability could be used by attacker to gain control of the targeted system with the rights of the current user.

ActiveX controls are used by Internet Explorer to connect with other applications and view content within the browser. Other browsers do not use the ActiveX controls and are not vulnerable to the attack.

Microsoft noted that copies of Internet Explorer which run in the Enhanced Security Configuration, such as those in Windows Server 2003 and 2008, will also be protected from the attack.

News of the attacks comes just one day before Microsoft is set to issue a monthly security release which for the first time in more than three years does not include a bulletin of 'critical' severity.