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  #41  
Old 10 December 2007, 10:07 AM
TomBernard
 
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Originally Posted by Insensible Crier View Post
Despite what you see in movies like Live Free or Die Hard, most computer systems are not fragile little networks where one logical error causes a huge catastrophe.
But isn't that the major point of the original article? They cited numerous instances of catastrophic (or near-catastropic) situations arising from seemingly minor glitches.

As far as other "history altering glitches" are concerned, I would nominate the guidance system on the Lunar Module in the Apollo 11 mission as a possible candidate. A single character from its guidance software was missing, causing the module's computerized guidance to (insert lengthy technical jargon here), nearly causing the landing to be aborted.
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  #42  
Old 15 December 2007, 03:56 PM
AndrewR
 
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Originally Posted by Troberg View Post
I'm not arguing that firewalls do no good, I'm arguing that several levels of firewalls give little additional benefit. If one level is breached, the next can also be breached. Of course, this is assuming that the same product is used with the same settings, but that's usually the case.
Multiple firewalls can give significant benefits. Consider a corporate environment with users who have laptop computers: when on the corporate network, the firewall at the edge of that network protects the laptops; but what about when the users are working from home, or in a hotel, or on a client site, or (insert other scenarios where the user might connect their laptop to an unsecured network)? There needs to be something to protect those PCs when they are connected outside of the corporate firewall, otherwise not only are those machines vulnerable to infection, they are also providing a route for infections to bypass the corporate firewall.
There's also a case for having protection within the corporate network, for example to limit the spread of an infection that does get in or to keep unauthorised devices off the network.
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  #43  
Old 15 December 2007, 05:09 PM
Troberg Troberg is offline
 
 
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As far as other "history altering glitches" are concerned, I would nominate the guidance system on the Lunar Module in the Apollo 11 mission as a possible candidate. A single character from its guidance software was missing, causing the module's computerized guidance to (insert lengthy technical jargon here), nearly causing the landing to be aborted.
They lost one Voyager probe due to a "." being substituted for a "," and they lost a Venus probe (now that sounds naughty) due to the opposite problem. Maybe it was the other way around, my memory is a bit shady, but it's close enough.

Quote:
Multiple firewalls can give significant benefits. Consider a corporate environment with users who have laptop computers: when on the corporate network, the firewall at the edge of that network protects the laptops; but what about when the users are working from home, or in a hotel, or on a client site, or (insert other scenarios where the user might connect their laptop to an unsecured network)? There needs to be something to protect those PCs when they are connected outside of the corporate firewall, otherwise not only are those machines vulnerable to infection, they are also providing a route for infections to bypass the corporate firewall.
There's also a case for having protection within the corporate network, for example to limit the spread of an infection that does get in or to keep unauthorised devices off the network.
Of course, if you can't keep a decent shell protection, such as if laptops are used, extra protection is needed. I would probably set up a separate sub network, shielded from the rest of the network by a firewall, for the laptops to keep it simple, but that's not always possible.
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  #44  
Old 15 December 2007, 10:22 PM
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ganzfeld ganzfeld is offline
 
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Quote:
Originally Posted by TomBernard View Post
As far as other "history altering glitches" are concerned, I would nominate the guidance system on the Lunar Module in the Apollo 11 mission as a possible candidate. A single character from its guidance software was missing, causing the module's computerized guidance to (insert lengthy technical jargon here), nearly causing the landing to be aborted.
I want to know more about this but couldn't find it in the articles I have describing the Apollo 11 software problems. Could you tell me where I can find more information about this?
Quote:
Originally Posted by Troberg View Post
They lost one Voyager probe due to a "." being substituted for a "," and they lost a Venus probe (now that sounds naughty) due to the opposite problem. Maybe it was the other way around, my memory is a bit shady, but it's close enough.
I couldn't find any information about these either. I'd really like to confirm these stories and any further information would be be much appreciated.

Last edited by ganzfeld; 15 December 2007 at 10:28 PM.
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  #45  
Old 16 December 2007, 06:59 AM
Troberg Troberg is offline
 
 
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I couldn't find any information about these either. I'd really like to confirm these stories and any further information would be be much appreciated.
I'll see what I can find. I heard it through word of mouth, although from a person who at the time worked in the Swedish space program. For the Voyager probe, it meant that the antenna was misaligned, and it lost contact with earth. For what I can find on the Voyager now, it seems like they are both more or less operational, so it's probably wrong. It may be a misinterpretation of this event (from Wikipedia):

"On November 30, 2006, a command was incorrectly decoded by the spacecraft as an instruction to turn on heaters associated with the probe's magnetometer. The heaters remained on until December 4, 2006, resulting in extremely high temperatures (above 130 °C), and in sensor rotation away from the correct orientation. It has not been possible to fully diagnose and correct for the damage to the Voyager 2 magnetometer, although efforts to do so are ongoing."

As for the Venus probe, perhaps it was the naughty kind after all?
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  #46  
Old 19 December 2007, 11:21 PM
BluesScale BluesScale is offline
 
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Since this rather drifted into a "Windows is teh suxxor, Linux is teh roxxor" debate, I thought that I would throw in this new ZDNet article

http://blogs.zdnet.com/security/?p=758

"So this shows that Apple had more than 5 times the number of flaws per month than Windows XP and Vista in 2007, and most of these flaws are serious. Clearly this goes against conventional wisdom because the numbers show just the opposite and it isn’t even close."

The comments are interesting. There seem to be two basic tacks. One is to attack the data as it can't be true though Secunia vuln numbers are listed. The second tack is to say that the vulns for Mac don't matter because Blackhats don't use them. Can't claim to be impressed by either argument

Blues
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  #47  
Old 20 December 2007, 04:47 AM
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Psihala Psihala is offline
 
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Quote:
Originally Posted by TomBernard
As far as other "history altering glitches" are concerned, I would nominate the guidance system on the Lunar Module in the Apollo 11 mission as a possible candidate. A single character from its guidance software was missing, causing the module's computerized guidance to (insert lengthy technical jargon here), nearly causing the landing to be aborted.

Quote:
Originally posted by ganzfeld
I want to know more about this but couldn't find it in the articles I have describing the Apollo 11 software problems. Could you tell me where I can find more information about this?
While it doesn't mention the "single character from its guidance software" specifically, Gene Kranz's book, "Failure is not an Option" describes in fairly good detail what the problem was during the landing of Apollo 11. Gene Kranz was the flight director on duty for the landing of Apollo 11 (he was also the flight director on duty when the problem with Apollo 13 occurred.)

In a nutshell, and I'm paraphrasing because I don't have the book in front of me, the computer was generating a 1401 alarm -- which indicated the LEM computer was having difficulty keeping up with the information it was supposed to be keeping track of.

During the many training sessions leading up to this particular mission, the Simulation supervisor (SIMSUP) inserted this very alarm into the simulation, prompting an abort. Kranz made it very clear in his book that a 1401 alarm was not an abort situation given no other indicators of a potential failure of the system.

~Psihala

ETA: There was an additional problem in the landing: when the LEM was undocked from the CM, air trapped in the tunnel between the two spacecraft imparted a little extra push that had an effect on the trajectory. I think that issue was mentioned in another book, though (Sy Leibergots' "EECOM", I think).

It also occurs to me that the 1401 alarm may not be the guidance problem TomBernard was specifically referencing, but it seemed to be the one that most of the books I've read on the subject address.

Last edited by Psihala; 20 December 2007 at 05:09 AM.
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  #48  
Old 21 December 2007, 01:51 PM
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diddy diddy is offline
 
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Quote:
Originally Posted by BluesScale View Post
Since this rather drifted into a "Windows is teh suxxor, Linux is teh roxxor" debate, I thought that I would throw in this new ZDNet article

http://blogs.zdnet.com/security/?p=758

"So this shows that Apple had more than 5 times the number of flaws per month than Windows XP and Vista in 2007, and most of these flaws are serious. Clearly this goes against conventional wisdom because the numbers show just the opposite and it isn’t even close."

The comments are interesting. There seem to be two basic tacks. One is to attack the data as it can't be true though Secunia vuln numbers are listed. The second tack is to say that the vulns for Mac don't matter because Blackhats don't use them. Can't claim to be impressed by either argument

Blues
Actually Daniel Eran Dilger disputes the facts that your article presents. Short of it, the guy is incredibly anti apple biased. I really don't trust him.
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  #49  
Old 21 December 2007, 03:05 PM
BluesScale BluesScale is offline
 
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Yes, there has been quite a bit of criticism of that article.

I think that the fairest comparisons would put the two about level with Vista showing good promise of being the most secure yet.

I can say that a lot of the speculation about MS silently fixing security bugs is just that - speculation with nothing to back it up. I have access to the code base and the bug databases and it is clear that this isn't happening, at least, not as a matter of routine.

Blues
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  #50  
Old 24 December 2007, 04:07 AM
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lord_feldon lord_feldon is offline
 
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Quote:
(Note: We have purposely omitted incidents that resulted in loss of life.)
No fun....
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  #51  
Old 15 February 2008, 12:26 AM
jason13
 
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Quote:
Originally Posted by Troberg View Post
They lost one Voyager probe due to a "." being substituted for a "," and they lost a Venus probe (now that sounds naughty) due to the opposite problem. Maybe it was the other way around, my memory is a bit shady, but it's close enough.
The AT&T network collapse was caused by a similar error, a missing semi-colon (IIRC from SWE or engineering ethics classes).

The Ariane 5 bug was an even stupider bug -- the bug was in the portion of code recycled from the Ariane 4 that compensated for the effects of wind before launch and that didn't get shut off until a minute or so into flight. The Ariane 4 never blew up because it was slow enough that the buggy code was shut down before it got high enough that winds made enough of a different deviation to trigger the bug. (This was a bug we discussed in several classes.)

From the same class as the AT&T bug (or was it a RTP class?), the Mars Climate Orbiter problem was resolved because someone left the debugger on in VxWorks and they uploaded the patch that way.

The IEEE Spectrum ran an article on the Airbus problem -- the Germans used UNIX-based CATIA 4 written in FORTRAN while the French used the Windows-based CATIA 5 written in C++.
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  #52  
Old 22 August 2008, 12:13 PM
Shenshen
 
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Funniest disaster I can remember was while I was working for IBM.
It was a couple of years ago, during summer. Parts of Italy had had a power outage, affecting one of IBM's sever farms. That wasn't much of a problem, as there was a backup generator, and the servers remained up and running without problem.

However, when the power came back up, there was a surge which caused the wiring to catch fire. The entire server farm burned down. Which wouldn't have been the end of the world either, as there were of course backup servers.
In the building right next door to the burning building.
Which didn't take long to catch fire as well.

End result was that all Italian IBMers had to do without email for about a month, and half of IBM Europe's internal databases were lost altogether...
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