Microsoft is making available by way of Windows Update an updated version of its Internet Explorer 9 web browser that incorporates a number of recently released security fixes. Your computer will be updated automatically if you have Automatic Updates turned on. Internet Explorer 9.0.3 resolves a number of privately reported vulnerabilities in IE 6, 7, 8 and 9.
The most severe vulnerabilities could allow remote code execution if a user views a specially crafted Web page using Internet Explorer. An attacker who successfully exploited any of these vulnerabilities could gain the same user rights as the local user. Microsoft has said, If exploited, the bugs in Internet Explorer would expose the user to drive by download attacks just by merely browsing to a booby trapped site.