On Tue, 11 Nov 1997, Jay R. Ashworth wrote:
Date: 09 Nov 1997 09:26:39 +0100 From: Torsten Hilbrich <Torsten.Hilbrich@bln.de> Subject: New Pentium flaw
Yesterday (Nov, 8) I found the following information on the news-ticker page of the German Heise-Verlag (shortened to the essential information):
The Pentium in standard and MMX version halts on execution of the instruction: F0 0F C7 C8 This code sequence works independent of any memory protection of the operating system.
I was able to reproduce this bug on a Pentium 133 system with the following operating systems: DOS, Windows 95, Linux 2.0.31, and FreeBSD 2.2.x.
I don't know about PentiumPro and Pentium II.
The risk? Every pentium based server with user access for executing programs can be crashed using this code sequence. Not to mention Trojan Horses or Active-X controls.
Does anybody know if this affects the Cyrix and AMD "Pentium Clone" chips?