On, Wednesday, November 3, Microsoft issued a notification regarding vulnerability on Internet Explorer versions 6-8. The condition is still under investigation. As of this time, the best solution is to use the following mitigation steps
Implement Data Execution Prevention
Use a limited (non-administrator) ID when using a web browser.
Do not visit untrusted websites.
Microsoft Security Advisory (2458511)
Vulnerability in Internet Explorer Could Allow Remote Code Execution
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.
• Data Execution Prevention (DEP) helps protect against attacks that result in code execution and is enabled by default in Internet Explorer 8 on the following Windows operating systems: Windows XP Service Pack 3, Windows Vista Service Pack 1, Windows Vista Service Pack 2, and Windows 7.
• Protected Mode in Internet Explorer on Windows Vista and later Windows operating systems helps to limit the impact of the vulnerability as an attacker who successfully exploited this vulnerability would have very limited rights on the system. An attacker who successfully exploited this vulnerability on Internet Explorer 7 or Internet Explorer 8 could gain the same user rights as the local user. 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.
• In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit this vulnerability. In all cases, however, an attacker would have no way to force users to visit these Web sites. Instead, an attacker would have to convince users to visit the Web site, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes users to the attacker’s Web site.