The RISKS Digest
Volume 18 Issue 65

Monday, 9th December 1996

Forum on Risks to the Public in Computers and Related Systems

ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

Please try the URL privacy information feature enabled by clicking the flashlight icon above. This will reveal two icons after each link the body of the digest. The shield takes you to a breakdown of Terms of Service for the site - however only a small number of sites are covered at the moment. The flashlight take you to an analysis of the various trackers etc. that the linked site delivers. Please let the website maintainer know if you find this useful or not. As a RISKS reader, you will probably not be surprised by what is revealed…


Limits of automated newsgathering
Terry A. Ward
Crypto to protect ``bomb'' throwers
Peter Wayner
Another banking system hits the dust
John C. Bauer
Software hunts and kills Net viruses
Hans A. Rosbach
Don't touch this switch!
Rick Simpson
Blown Fuse Takes Out 911 System
Scott Lucero
Web content-substitution attack was a proxy-server fault
James Cameron
Risks of inappropriate encouragement
David M. Chess
Reuters computer tech brings down trading net
Steve L
Combatting cookies
Simson L. Garfinkel
MS-Access Runtime trashes WFW
Bob Price
Snowjob in selling computer books
Al Donaldson
"Computer errors cause several plane crashes"
Martin Minow
RISKS of frequent-flier long-distance promotions
Jonathan Clemens
Year 2000 and expiration dates
Robert Nicholson
Centralized computing
Darin Johnson
Re: Bell Atlantic 411 outage
Robert J. Perillo
Info on RISKS (comp.risks)

Limits of automated newsgathering

"Terry A. Ward" <>
Wed, 4 Dec 1996 11:35:55 -0800
I subscribe to the NewsPage Direct automated news service and a recent
selection in HUMAN SEXUALITY highlighted the risk of confusing a rugby
position with a sex-workers position:

   hooker Karl Svoboda has been ousted from the Oxford team to face
   Cambridge University in the showpiece Varsity match at Twickenham
   next Tuesday.  (Reuters)

      [This is a scrum-ptious item!  TNX.  PGN]

Crypto to protect ``bomb'' throwers

Peter Wayner <>
Mon, 9 Dec 1996 18:07:30 -0500
*The Washington Post* (6 Dec 1896) reported that a radio and television
broadcast of the annual Army/Navy football game would be distributed to many
of the ships at sea in "encripted" form.  The signal would be used to boost
morale, although the encryption may ruin morale for the folks stationed at
NSA/DIA listening posts.  But perhaps the algorithm will be simple enough to
be part of the challenge for them.

Of course, the automatic word scanners are sure to light up when words like
"bomb" and "blitz" come over the air.

I wonder if they sign the broadcast with a digital signature to make sure an
authentic version reaches the troops?  Spoofed versions would be true info
warfare.  The enemy could ensure that both divisions would be demoralized
by feeding a doctored version to the winning side.  But then there is still
the RISKS of the Air Force, who are in the big-bomb delivery department.

  [Incidentally, for non-U.S.-football devotees, a "bomb" is a long pass,
  and a "blitz" is an extra-man defensive attack.  I suppose "getting
  sacked" has multiple meanings in an Army-Navy game.  PGN]

Another banking system hits the dust

"John C. Bauer" <>
Mon, 2 Dec 1996 14:38:39 -0500
  On 30 Nov 1996, the Canadian Imperial Bank of Commerce Interac service was
  victimized by its attempted software upgrade, affecting about half of all
  would-be transactions across eastern Canada.  [Source: Debit card failure
  angers customers, by Colin Freeze, Citizen Correspondent, The Ottawa
  Citizen, 2 December 1996, Ottawa, Ontario, Canada.  PGN Stark Abstracting]

One business affected was Loblaw's, a grocery chain.  Grocery stores do not
accept credit cards.  (My wife Ann says it may a provincial law.)  I can
just see someone with a cartful of groceries arriving at the checkout and
being asked for cash they are not carrying.

As of 1 p.m. EST, 2 Dec 1996, the local branch of the bank had no statement
to give to customers!  Will this be touted as another example of computer
people living outside the real world, where shopping is at a peak on
Saturday afternoons, especially near Christmas?

Software hunts and kills Net viruses

Hans A. Rosbach <>
02 Dec 1996 18:52:31 +0100
*The Sunday Times* (1 Dec 1996) wrote:

  Software hunts and kills Net viruses

VIRUS-KILLING computer software that uses artificial intelligence to find
and destroy new viruses is to be set loose on the Internet by IBM next week.
The software, originally developed to play backgammon, will spread itself
through the Net over the next year, learning how to kill new strains of
virus as it goes.  According to Gregory Sorkin, a researcher at IBM's Watson
research laboratory, the system will be far more successful than humans at
fighting computer viruses.  "Once it learns the viruses already out there,
the system will even be able to predict what new viruses will appear, and
work out ways of stopping them before they even exist," says Sorkin.  The
system uses temporal difference, a method which relies on the computer
looking for patterns within virus software, rather than individual lines of
program code.

  If I understand it correctly, this is software that will spread itself on
  the net, adapt itself, and destroy other things on the net.

  How can something like this be tested?  How can we be sure that the
  technology behind it will not be used to create the next generation of
  viruses?  I find this scary.

Hans Amund Rosbach

Don't touch this switch!

"Rick Simpson" <>
Thu, 05 Dec 96 18:13:54 -0500
Today I attended a meeting in a large office building of a Major
Computer Company.  As I entered the conference room, the organizer of
the meeting was trying to find a way to lower the projection screen
from its storage place in the ceiling.  There was no cord attached, so
he was searching for a switch for the screen's motor.

On the wall next to the door was a push-button switch, brightly
backlit in red, with a hand-written sign that read, "Don't touch this
switch."  (Also scribbled on the sign, in another hand, was "Don't
touch" in Spanish.)  The organizer seemed to think this might control
the screen, so he pressed the button.  Needless to say, the screen did
not descend.  The ventilation fans went off, though.

Several minutes later, a fellow poked his head in the door and asked,
"Did someone touch that switch?"  [Just like in a cartoon, isn't it?]
"Yes," the organizer said, "we were trying to get the screen down."

"Don't touch the switch," said the man in the door, "It turns off the
computer room next door."

The conference room was evidently once part of a raised-floor machine room,
and the Emergency Power Off switch next to the door is still active.

The RISKS, I submit, are too obvious to list.

Rick Simpson  IBM T. J. Watson Research Center  Yorktown Heights, New York

Blown Fuse Takes Out 911 System

lucero <>
Tue, 03 Dec 96 05:21:48 EST
National Public Radio reports that a blown fuse took out a large portion of
Iowa's 911 emergency phone system for three hours over the Thanksgiving
weekend.  U.S. West could not say how many 911 calls went unanswered.  A
spokesperson said that the troubles isolating the problem came from the
complexity of the system.  The RISKS are pretty evident.

Scott Lucero  U.S. Army Software Metrics Program

Web content-substitution attack was a proxy-server fault

James Cameron <>
Tue, 3 Dec 1996 14:05:50 +1100
I heard from a friend a detailed account of an apparent content substitution
attack on his corporate web server that highlights a couple of risks.  With
his permission I have summarised the order of events:

 - A few days ago, a sales person employed by the company reported a
   pornographic image had replaced the corporate logo on the main page.

 - A correct logo was downloaded to the server within minutes, but
   before saving the existing image, thus erasing the evidence.

 - Research showed a known defect in the operating system code that
   can be exploited to yield root access by remote users.  Tests showed
   that the firewall and web server were vulnerable.  Patches were
   obtained and installed to remove the vulnerability.  Much effort.

 - Conflicting data from logs appeared.  The web server logs showed
   that the image had not been replaced.  Firewall logs agreed.  Web
   proxy server logs claimed otherwise.

 - The pornographic image was found in the web proxy server cache,
   with a different URL, using a search by file size, and the logs
   confirmed that it had been viewed by users within the company.

 - No evidence was found to prove that a break-in had occurred.

The staff deduced that the web proxy server had somehow mixed the pointers
to the cached images, and had returned the incorrect image to the internal
users.  No reports were received from Internet users.

Risk: a web proxy server may change your view of the Internet, and may cause
you to waste considerable time tracing a break-in that didn't happen.

Risk: allowing staff full access to the web increases the chances of a file
mixup causing disturbance.

Also, there were no controls to ensure that CERT notifications were integrated
into the firewall configuration.  It took a suspected break-in before a search
was made for vulnerabilities.

James Cameron                                    (
Digital Equipment Corporation (Australia) Pty. Ltd. A.C.N. 000 446 800

Risks of inappropriate encouragement

"David M. Chess" <>
Wed, 4 Dec 96 10:39:13 EST
My daughter has a few multi-media-type CD-ROM games, and they are to various
degrees cute / cuddly / talkative / friendly.  The most talkative and
friendly one has one very annoying and counterproductive habit.  In the
find-the-hidden-objects puzzle, the little voices on the speakers say happy
/ reassuring things every time you click the mouse on a place where there's
no hidden object.  "Try again!"  "Nope, not there!" and so on.  The
encouraging phrases are as far as I can tell picked at random.
Unfortunately, some of them have *semantics* beyond just "Try again".

The most annoying ones are "Ooh, not quite!" and "You're getting closer!".
Because they're generated just at random, the voices can say "Ooh, not
quite!" when the player is clicking as far as possible from the target, and
can say "You're getting closer!" when in fact you're getting further away.
My daughter learned to ignore the semantics of these messages very quickly
(the plasticity of youth), but when looking over her shoulder I still find
them annoying and misleading, and have to remind myself that they're

The general tendency, the risk category, is a familiar and important one:
computers that talk seem from the outside to know what they're saying,
whereas the people who've made them talk may not really have thought it
through at all, and the programs themselves can be arbitrarily stupid.

(Another similar program will say encouraging things like "Your eyes are as
sharp as the eagle's" when the child finally gets all the rolling targets in
the archery game, even if the player is far beyond the age-appropriate
difficulty level, and has been struggling for many minutes to hit each one.
Another, related, risk that reaches far beyond computers: overgenerous

David M. Chess  High Integrity Computing Lab  IBM Watson Research

Reuters computer tech brings down trading net

Mon, 02 Dec 96 16:02:11 EST
  Dealing rooms sabotaged by HK Reuters technician
  By Nicholas Denton in London and John Ridding in Hong Kong, 29 Nov 1996
  Financial Times Limited

  A disgruntled computer technician at Reuters in Hong Kong has caused the
  financial-information provider deep embarrassment by sabotaging the
  dealing-room systems of five of the company's investment bank clients.
  The attack crippled for up to 36 hours the computer systems bringing
  market prices and news to traders at NatWest Markets, Jardine Fleming,
  Standard Chartered, and two other banks.  The banks, which resorted to
  alternative terminals such as Bloomberg, claimed the tampering had no
  significant impact on trading and said neither they nor their clients had
  experienced losses as a result.

The incident was reportedly the most serious breach of security disclosed in
Reuters' corporate history, and is causing some rethinking of privileges.
The maintenance engineer in question has been suspended.  He apparently
visited the client sites and initiated deferred commands to subsequently
delete specific operating system files.

Combatting cookies

"Simson L. Garfinkel" <>
Tue, 03 Dec 1996 08:25:13 -0500
I've been thinking a lot about (web) cookies lately.  One of the problem
with the current situation is that you basically have two choices with the
User Interface that both Netscape and Microsoft have created for your

  1. You can simply accept all cookies.
  2. You can have your browser warn you every time a cookie is sent
     your way and have the option of accepting it or not.

A cookie, for those not in he know, is a little tarball of data that gets
sent to your browser. Cookies can be used to track users, by keying their
browsers to a database. Or they can be used to preserve privacy, by storing
private information on the user's browser, rather than on the web server.

Right now, a cookie gets sent to your browser whenever you get an HTTP
response with the words "Set-Cookie:" in the header. After that, whenever
you contact the web site, you send the cookie back.

It seems to me that an excellent way to deal with the cookie problem would
be to have more user interface options:

  * Simply do not accept cookies.
  * Specify who you will accept cookies from, and who not.
  * Accept cookies, but do not send them back.
  * Have a decent user interface to show which cookies you have and how
    often they are used. Let you delete them individually, rather than just
    all or nothing.

I've written more about cookies in an upcoming article for HotWired. It will
appear at on Wednesday, 11 Nov 1996.

MS-Access Runtime trashes WFW

Tue, 3 Dec 1996 13:25:24 -0500
Unless especial pains are taken, 16-bit MS-Acess runtime disks made on a
Windows-95 machine with 16-bit Access will cause near-irreparable harm when
installed on a WFW or Windows 3.1 machine.  The reason is that some 32-bit
system .DLLs are copied to the distribution diskettes (or network
distribution set) along with the 16-bit files, and because the 32-bit files
have the same names as the 16-bit files, the 16-bit platform no longer works
properly.  I'm told the official Microsoft paper on the subject says to
format the hard drive and re-install everything.  I was able to "recover" by
upgrading to Windows-95; others have had success ferreting out the specific
files and replacing them.  Reinstalling WFW didn't fix anything.

Bob Price  Cable & Wireless Inc.  (703)760-3071

Snowjob in selling computer books

Al Donaldson <>
Tue, 3 Dec 96 14:43:48 EST
January 1996 was a snowy month in Virginia.  We were hammered by a storm on
the 6th that dropped about two feet of snow, and closed everything (that
wasn't already closed) for a couple of days, followed by another storm on
the 12th that gave us another 8 or 10 inches.

So that Friday (12th), I spend most of the afternoon shoveling out my
driveway.  Then, remembering that I needed to buy a book to prepare for some
computer work that weekend, I called my favorite technical bookstore to see
if, by some chance, they might be open that night.  (I didn't really expect
them to be open, but it was worth a try...)

Sure enough, someone answered, so I asked how late they would be open.
"Nine o'clock," was the answer.  I confirmed the closing time, perhaps still
not really believing they'd be open, then drove my 4WD truck about 15 miles
on snowy roads to get there.  But when I arrived around 8:00pm, the store
was quite obviously closed.

That evening I sent off a letter of protest to the store management, who
responded the following Monday that the *Virginia* store had been closed all
day because of the heavy snow, and they'd forwarded the phones over to one
of their California stores.

"Computer errors cause several plane crashes"

Martin Minow <>
Fri, 6 Dec 1996 17:15:03 -0800
>From an article in the Swedish newspaper, Aftonbladet, Dec 6, 1996
written by Claes Thunblad.

[[Note: while the Swedish translations I send to RISKS are usually from
*Svenska Dagbladet*, one of the two "newspapers of record," this is from an
evening tabloid, and should be understood as such. If you imagine my other
translations as originating from *The New York Times* or *Daily Telegraph*,
think of this as from the *New York Post* or *Evening Standard*.  I've tried
to be both accurate and true to the tone of the article.  I've translated a
bit more than 50% of the article, but omitted the sidebars listing recent
air accidents. Swedish typographic conventions make it difficult to
precisely mark quotations, and I apologize for any errors.]]

The advanced computer systems developed to improve flight safety have become
a death trap. "Pilots can no longer keep track of everything," says Per-Olof
Sk=F6ld, president of the Swedish pilot's organization.  [[In bold-face on
the web page.]]

"We've discussed this problem on several occasions. The critical point is
when the computer system should be disconnected; when the pilot stops being
a passive monitor of the system and becomes an active operator," says
Sven-Eric Sigfridsoson of the national air accident commission.

The new advanced technology in airplanes was developed by technicians and
engineers. They're the ones who test-fly the system before the plane is put
into traffic.

"These things were designed by engineers and technicians are not always
pilot-friendly. Today there are several automatic sequences that pilots can
never keep track of," says Per-Olof Sk=F6ld. ... The pilot's nightmare
scenario is that the technology will get even more advanced.

That's what the technicians want.

RISKS of frequent-flier long-distance promotions

Jonathan Clemens <>
Tue, 3 Dec 1996 11:56:58 -0800 (PST)
Several years ago, a local long distance carrier began a program offering
one frequent flier mile for each minute of long distance calling. My sister
signed up for the program, but later moved and disconnected that particular
phone line.

However, recently she began receiving program statements again. It seems
that number has been reissued, and the new owners have this long distance
carrier, but have NOT signed up for the "Mile-A-Minute" program.

When reassigning a number, all features should have been reset to their
defaults.  In this case, they were obviously not.  The total 'cash' value
(at $.03 per mile) of the error is not very significant.  A more serious
risk is that my sister receives a detailed billing report every month,
listing the number called and the call duration for each qualifying
number. It is sent to the address listed on her frequent flier account, and
not to the billing address of the new owners of the line.

In addition to eliminating 'old' data, such systems need to take into
account the nature and sensitivity of data disclosed on such statements.

Jonathan Clemens,

Year 2000 and expiration dates

Sat, 7 Dec 1996 19:35:02 +0000
Today, I had my first encounter with the year 2000 problem. I took my shiny
new, already activated, Visa cheque card into Citibank, Manhattan branch and
after inserting the card into the validation machine the teller told me my
card had expired. My expiry date is 01/00.  A few moments later I had
successfully convinced that teller that the card couldn't have been issued
in the 1800's and so he phoned a verification service to check. That service
also declined the card. It wasn't until I had called my own bank and asked
them to turn off all security checks on the card that I could successfully
obtain my cash advance.

I had earlier dismissed all the hype surrounding the year 2000 problem
thinking that most corporations would have already made the necessary
changes to cope. Considering it's typical for cards to be issued for 4 year
periods it's not surprising to see a card issued in 1996 suffering this
problem. I can only hope things improve as we approach 2000.

Robert Nicholson <>

Centralized computing

Darin Johnson <>
3 Dec 1996 18:43:51 GMT
A few months back, I was shopping at a Computer City, a large chain of PC
stores of the sort that caters to the mass market.  When I got to the front
of the checkout line (which is normally slow to begin with), things came to
a halt.  Apparently, all transactions were handled by computer, and it was

OK, I thought they've got a backup in the back, and it'll kick in, or the
thing will reboot.  No good.  After awhile, one of the clerks reported that
the computer that was down was in LA (I was in San Diego).  All their
transactions were being handled remotely, and for all the computers and
manpower they had locally, they couldn't do anything but wait.

Later still, someone came back up front with a book describing how to do
checkouts manually.  None of the clerks knew.  When I was checked out, it
took four people, one to be in charge, one to use the calculator to compute
tax and total, one to verify my credit card, and one to read the instruction

I was struck by two ironic facets of all this.  First, the reliance upon
centralized computers.  The PC got its big start and popularity run
initially by allowing independent computer use away from centralized MIS
departments.  Have things come full circle again, away from independent
computers to centralized ones?  It would not have been unreasonable for a
computer seller to have an extra backup computer in back, something to
process transactions locally and then transmit them remotely later.  Perhaps
the risk here is forgetting history (not to stereotype too blatantly, but I
see a distinct lack of historical computer knowledge in much of industry).

The second facet is the old risk of becoming too dependent upon technology.
Requiring four people to check out one small purchase is excessive, and all
because none were trained to do such things manually (not to stereotype too
much again, but they didn't seem to be trained that well in computers either
:-).  On the other hand, I can go into grocery stores and have the checkers
rapidly process a large purchase, knowing the price of each item; I've had
other stores take only one person to fill out receipts by hand when power
was out.  Why would a computer store be so crippled by a remote computer
being down, were they even more dependent upon technology than other stores?

Darin Johnson

  [Yes, this is an old tale for RISKS readers.  But did
  you think a computer store would know better?  PGN]

Re: Bell Atlantic 411 outage (RISKS-18.63)

Wed, 4 Dec 96 14:28 EST
This was not a complete outage, but about 60% of the Bell Atlantic company's
2,000 operator's at 36 sites could not log into their automated directory
system. Of the 40% that were able to access the database, lookup times went
from the typical 19 seconds into minutes. The problem manifested itself
about 8am on Monday November 25th, and was fixed about seven hours later by
reloading the previous version of the database software. But this was the
most extensive directory-assistance failure since telephone operators
started using computers, affecting hundreds of thousands of customers in
nine eastern states.

Originally Bell Atlantic blamed the problem on a "software glitch" in the
"Nortel Directory One" database software upgraded over the weekend. Northern
Telecom stated that the new software, which was meant to correct minor
errors in the previous version, was being used by several large phone
companies without any problems.  The problem seems to have been traced to a
Nortel technician who improperly installed the software on two RS/6000
servers. The incorrect installation of the main database, also somehow
caused the same type of access problems on the duplicate/backup database

While RISKS has concentrated on software errors, installing software into
operating systems has gotten increasingly complex, usually done by
non-degreed technicians and operators, following informal instructions
scrawled on the back of napkins. In this case it seems that since the
malfunction was load related, the technician was unaware during system
checkout that the database was incorrectly installed. More scrutiny should
be given to software installation, and installation procedures or possible
problems. Formal procedures with Quality Assurance (QA) checklists should be
used. Could automated installation programs, or problem checking software,
be used to prevent or detect installation problems?

References: "Software Glitch Snarls Bell Atlantic's 411 Calls",
            Washington Post, 11/26/96, page D1 .

            "Bell Atlantic Customers Are Put on Hold by Directory
             Assistance", New York Times, 11/26/96, page A17.

            "Software Glitch Hits Bell Atlantic Sites", InformationWeek,
            12/2/96, page 32.

Robert J. Perillo     Staff Computer Scientist

Please report problems with the web pages to the maintainer