Microsoft has issued a patch to address an Internet Explorer vulnerability that one leading security organisation described as probably "the most dangerous flaw found in Windows workstations" to date.
The so-called IE Script hole was discovered last month by infamous Bulgarian bug hunter Georgi Guninski.
It lets crackers embed malicious Visual Basic code into Microsoft's Access database management software via Internet Explorer.
Victims can be compromised by simply visiting a rogue Web site or by previewing email containing malicious code, without actually opening any attachments or executing files, according to a security flash issued today by the US based System Administration, Networking, and Security Institute.
SANS is a nonprofit institute focused on education and research in several information technology areas, including information security.
What makes the hole such a dangerous programming error in Windows software is that it allows crackers to potentially take full control of a victim's computer, according to Alan Paller, director of SANS.
"It allows [a cracker] to do anything I can do as a user of my computer," Paller says.
This includes editing files, deleting them, or e-mailing them to remote destinations without a user's knowledge.
All users of Windows 95, 98, 2000, and NT 4.0 workstation who have installed Microsoft Access 97 or 2000, while running Internet Explorer 4.0 or higher, are vulnerable to this sort of "total compromise," according to the SANS alert.
Microsoft's work-around is to set an administrator password for Microsoft Access.
This will cause Microsoft Access to prompt the user for a password before any Visual Basic for Applications code is executed within an Access database, according to a Microsoft FAQ on the subject.