Re: BoS: WARNING: Serious Pentium Bug

Robert C. Casas Ph.D. (rcc@COMSECLTD.COM)
Tue, 11 Nov 1997 17:23:40 -0600

At 07:36 AM 11/8/97 +0100, you wrote:
>
>There is a SERIOUS bug in all pentium CPUs. The following
>code will crash any machine running on a pentium CPU, MMX or no
>MMX, any speed, regardless of OS (crash as in instant seize, hard
>reboot the only cure):
>
>[SNIP]

FYI, this also crashes a 486 (iDX2-66 circa 1993 vintage)running MS-DOS
6.22.

The effects on Pentiums (586) vary depending upon the family/stepping
group,
and OS (DOS/Win 3.x/Win95a or b, Win NT 4.0 w/SP3), and range from slow
downs,
erractic behavior, to hard system lock ups. Every machine/OS combination
tested
was affected.

It is serious, mostly from a security perspective, though, since
legitimate
programmers would have no use for this snippit of code. Since this is a
security issue, I agree with your position on replacements ( or some form
of work around ) from Intel.

The security risk scenarios are unpleasant to contemplate. The magnitude
of the problem is enormous. Estimates suggest 80-90%+ computers are
running Intel CPU's.

I talked with an Intel representative today. They haven't yet established
a policy on how to deal with the issue but I was told they are
"aggressively"
doing so and expect to have one set up within a week. The number to call
at
Intel to reach the group handling the bug issue is: 1-800-628-8686.

-rcc

______________________________________________________________________
Robert C. Casas, Ph.D., COMSEC Ltd., Computer Security & Data Recovery
Telephone: 847-729-3565 FAX: 847-729-3575 On CompuServe: GO COMSEC
Email Address: rcc@comsecltd.com Web site: http://www.comsecltd.com
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