By David Morgenstern
February 16, 2004

A security company on Monday alerted clients of a new vulnerability to Internet Explorer 5, one attributed to the recent leak of Microsoft Corp. Windows source code. The quick attack appears to contradict some optimistic expectations that the recent leak of Windows 2000 and NT code would not pose a significant opportunity for hackers.

According to a message posted by LLC's Security Tracker Web site, a vulnerability was reported in Microsoft Internet Explorer Version 5 that lets a "remote user execute arbitrary code on the target system."