The December 2011 Cumulative Security Update for Internet Explorer is now available via Windows Update. This security update resolves three privately reported vulnerabilities in Internet Explorer. The most severe vulnerabilities could allow remote code execution if a user visits a specially crafted Web page using Internet Explorer. An attacker who successfully exploited this vulnerability could run a malicious application on the affected system. Users whose accounts are configured to have fewer user rights on the system could be less affected than users who operate with administrative user rights.
This security update is rated Important for Internet Explorer on Windows clients and Internet Explorer 9 for Windows 2008 R2; and Low for Internet Explorer on Windows servers. For more information, see the full bulletin.
Most customers have enabled automatic updating and do not need to take any action. We recommend that customers, who have not enabled automatic updating, enable it (Start Menu, type “Windows Update”). We recommend that administrators, enterprise installations, and end users who want to install this security update manually, apply the update immediately using update management software or by checking for updates using the Microsoft Update service.
—Ceri Gallacher, Program Manager, Internet Explorer