Protect Your Computer from the Latest Internet Explorer Vulnerability

Yesterday Microsoft issued an advisory regarding reports over a browser vulnerability affecting Internet Explorer 6, 7, and 8. This vulnerability enables remote code execution, in other words, an attacker can remotely run commands and code on your computer. Microsoft is currently investigating these reports and will issue further guidance upon completion of investigation. Guidance may include an out of cycle or monthly patch to fix this problem. Protect yourself by following the guidance below and learn more by visiting Microsoft’s Security Advisory page.

How to Protect Yourself

The following steps should help you mitigate the effects of this vulnerability.

  • Update your computer’s operating system (Windows), applications, and security software.
  • If you continue to use Internet Explorer make sure to use it Protected Mode on Windows Vista. You can also use a non-administrator account to prevent administrative changes on your computer.
  • Use another browser (Internet Explorer 9 Beta, Chrome or Safari).
  • If you are using supported versions of Microsoft Outlook, Microsoft Outlook Express, and Windows Mail open HTML e-mail messages in the Restricted sites zone, this disables script and ActiveX controls wich removes the risk of an attacker using the vulnerability to execute malicious code.

Executive Summary

Excerpt from Microsoft website.

Microsoft is investigating new, public reports of a vulnerability in all supported versions of Internet Explorer. The main impact of the vulnerability is remote code execution. This advisory contains workarounds and mitigations for this issue.

The vulnerability exists due to an invalid flag reference within Internet Explorer. It is possible under certain conditions for the invalid flag reference to be accessed after an object is deleted. In a specially-crafted attack, in attempting to access a freed object, Internet Explorer can be caused to allow remote code execution.

At this time, we are aware of targeted attacks attempting to use this vulnerability. We will continue to monitor the threat environment and update this advisory if this situation changes. On completion of this investigation, Microsoft will take the appropriate action to protect our customers, which may include providing a solution through our monthly security update release process, or an out-of-cycle security update, depending on customer needs.

We are actively working with partners in our Microsoft Active Protections Program (MAPP) and our Microsoft Security Response Alliance (MSRA) programs to provide information that they can use to provide broader protections to customers. In addition, we are actively working with partners to monitor the threat landscape and take action against malicious sites that attempt to exploit this vulnerability.

Microsoft continues to encourage customers to follow the “Protect Your Computer” guidance of enabling a firewall, applying all software updates and installing anti-virus and anti-spyware software. Additional information can be found at Security at home.

For updated information visit the Microsoft Security Advisory (2458511) website.