Another security problem has cropped up to plague Microsoft's browser software.
The company has admitted a vulnerability in its Internet Explorer 5 that could allow a malicious Web site operator to read the files on the computer of a person who goes to the site, or on other computers on that user's local intranet.
Microsoft said it is working to develop a patch to fix the problem. Meanwhile, it is advising users to protect themselves by disabling the Active Scripting feature in IE 5.
Microsoft posted a warning on its Web site saying it had discovered the flaw in an IE 5 feature called "download behaviour," intended to allow Web page authors to download files of client-side script, which is software designed to be run by the browser. Such software is designed to allow the Web site to only download files that are in its domain, and thus prevents the users' files from being accessed.
However, an ill-intentioned Web site operator could bypass domain restrictions and use download behaviour to gain read access to files on the user's machine or local intranet, according to the Microsoft Web site.
A malicious Web operator would have to know specific file names to read them and could not copy, delete or alter them, said Scott Culp, a Microsoft security product manager. He added that there have been no reported security breaches.
The problem was reported by Georgi Guninski, a Bulgarian programmer who earlier found another Microsoft security flaw, Culp said.