Snapshot Viewer allows users to view an Access report snapshot without the full version of Microsoft Office Access.
According to Bill Sisk, security response communications manager for Microsoft, an attacker who successfully exploited the vulnerability could compromise the victim's system.
The vulnerability affects the ActiveX control for the Snapshot Viewer in Microsoft Office Access 2000, Microsoft Office Access 2002, and Microsoft Office Access 2003.
In order to exploit the flaw, an attacker would have to convince a user with a vulnerable system to visit a Web site hosting malicious content, or to click on a link in an e-mail or instant message that leads to a malicious site.
Online ads could also be used to initiate an attack. "It could also be possible to display specially crafted Web content by using banner advertisements or by using other methods to deliver Web content to affected systems," Microsoft's advisory warns.
Secunia, a computer security firm, says that this vulnerability is being actively exploited.
US-CERT says that it's unaware of any practical workarounds for this vulnerability. It recommends disabling the vulnerable ActiveX control in Internet Explorer by setting its kill bit.
It also suggests upgrading to Internet Explorer 7, which has offers some additional protections against ActiveX abuse.
Because the vulnerability can be used to give the attacker the same file privileges as the victim, US-CERT advises running user accounts with the minimum necessary privileges as a means of mitigating potential damage.