[38006] in bugtraq
Re: Did a 16-bit counter overflow shut down Comair?
daemon@ATHENA.MIT.EDU (Mike Nice)
Wed Dec 29 13:36:28 2004
Message-ID: <00a801c4ed56$5e7ce3f0$04d4a8c0@backroads.net>
From: "Mike Nice" <niceman@att.net>
To: <bugtraq@securityfocus.com>
Date: Tue, 28 Dec 2004 22:27:45 -0500
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> Earlier this year, an overflow of a 32-bit counter in Windows shut down
air
> traffic control over southern California for 3 hours:
>
> Microsoft server crash nearly causes 800-plane pile-up
> http://www.techworld.com/opsys/news/index.cfm?NewsID=2275
>
> This problem occurred because of a known design flaw in older versions of
> Windows:
>
> http://tinyurl.com/5n9gc
Not quite true. Although an old version of Win98 had an overflow, this
overflow was in the application, not the OS.
http://www.spectrum.ieee.org/WEBONLY/resource/nov04/1104nair.html
..."But it's a software glitch that makes the reboot procedure necessary in
the first place, says Riggs. And that glitch resides in an auxiliary
system-the VSCS Control Subsystem Upgrade (VCSU)."
"Inside the control system unit is a countdown timer that ticks off time in
milliseconds. The VCSU uses the timer as a pulse to send out periodic
queries to the VSCS. "
