Sept. Bug In IIS Impacts All IE Users, Too

Admitting some confusion, a security group Thursday said that it appears one of the vulnerabilities Microsoft disclosed last month affects more users than first thought.

According to a research note posted online by the SANS Institute's Internet Storm Center (ISC), MS06-053, an update and patch for a bug in the IIS server software's indexing, looks like it impacts all users of Internet Explorer.

"There is no ignoring that you do not need an IIS server in the picture," the ISC warning stated. "In fact, all you need is Microsoft's [IE] browser."

MS06-053, which was released Sept. 12, details a cross-site scripting vulnerability in IIS, but also recommends that users of Internet Explorer disable the browser's page encoding auto-detection feature. (By choosing View|Encoding, and deselecting "Auto-Select.")

"The confusion is if this is a server problem or a client problem."Microsoft's bulletin seemed to say it was the vulnerability could affect both Windows servers and clients. "Client systems could allow an attacker to run client-side script on behalf of a user," the bulletin went. "The script could spoof content, disclose information, or take any action that the user could take on the affected Web site."

At the same time, Microsoft downplayed the threat, saying that users would have to be lured to a site -- malicious or compromised -- that had not been patched in order to put themselves in harm's way.

The ISC recommended users ditch IE for an alternate browser, or disable encoding auto-select.