Microsoft Internet Explorer is prone to a cross-domain information-disclosure vulnerability. This vulnerability may let a malicious website access properties of a site in an arbitrary external domain. Attackers could exploit this issue to gain access to sensitive information that is associated with the external domain, such as cookies associated with a user's session on the external site.
Run all software as a nonprivileged user with minimal access rights.
Ensure that all non-administrative tasks, such as browsing the web and reading email, are performed as an unprivileged user with minimal access rights.
Do not follow links provided by unknown or untrusted sources.
Users should never visit sites of questionable integrity or follow links provided by unfamiliar or untrusted sources.
Set web browser security to disable the execution of script code or active content.
Disabling scripting and active content in the Internet Zone may limit exposure to this and other vulnerabilities.
Disable any services that are not needed.
Disable support for HTML email in the email client. This may limit email-based attack vectors for this and other vulnerabilities.
Microsoft has released a cumulative security update to address this issue. Reportedly, the fixes provided in MS06-013 may cause unintended breakage with certain ActiveX controls. Symantec has not confirmed this. Before deploying this patch in production environments, users should thoroughly test the patch to ensure that it doesn't interfere with other software.