The Risks Digest

The RISKS Digest

Forum on Risks to the Public in Computers and Related Systems

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

Volume 23 Issue 36

Friday 7 May 2004


Computer glitch gives out free gasoline
Jack Christensen
U.S. blunders with China, Iran keyword blacklist
Declan McCullagh
Risks of prisoner abuse vs. digital cameras
Lauren Weinstein
Auto-Blacklisting is a bad idea
Drew Dean
Re: Computer glitch grounds Atlanta flights
Tron Smith
Corrupted virus definition load blocks re-load
George Michaelson
Antivirus software prolongs viral life
Matthias Heiler
Challenge/response standards
Brent Laminack
Aus vs. Swiss speeding
Ivan Reid
Re: ... lost revenue from faulty speed cameras
Anthony Youngman
Michael Smith
Bertrand Meyer
MDT and a Fatal accident: a possibility?
Nick Lindsley
Info on RISKS (comp.risks)

Computer glitch gives out free gasoline

<"Jack Christensen" <>>
Wed, 5 May 2004 17:28:12 -0400

Some Michigan college students discovered that swiping their driver's
license instead of a credit card in pay-at-the-pump gasoline pumps allowed
them to fill up for "free."  What they evidently didn't count on was that
information from their driver's licenses, sufficient to trace them, was in
fact read and stored by the system.

The exact mechanism of the "glitch" isn't detailed, but there are at least a
couple Risks here, including:

(1) Insufficient testing/robustness, with regard to unexpected input, can
    lead to retail losses and/or expenses to recover the losses, and

(2) Failure to understand that ignorance (in this case, of the workings of
    embedded systems, and of their failure modes,) is insufficient reason to
    assume a best-case scenario.

I know nothing of the specific technology involved, but I'm at least a
little surprised at the interchangeability of different types of cards.  I
would think one of the first checks would be to determine if you were
reading a credit card, or something else that you didn't want to process
(driver's license, video store card, etc.)

Strictly from personal observation when using these pumps, there is usually
some sort of authorization that happens before you can dispense gasoline.
If this authorization fails, as I assume it would when given a driver's
license, then I would not think the transaction should proceed.

[Source: Associated Press item, 5 May 2004]

Jack Christensen

U.S. blunders with China, Iran keyword blacklist (Politech)

<Declan McCullagh <>>
Mon, 3 May 2004 11:20:10 -0500

Declan McCullagh: U.S. blunders with keyword blacklist, 3 May 2004

The U.S. government concocted a brilliant plan a few years ago: Why not give
Internet surfers in China and Iran the ability to bypass their nations'
notoriously restrictive blocks on Web sites?

Soon afterward, the U.S. International Broadcasting Bureau (IBB) invented a
way to let people in China and Iran easily route around censorship by using
a U.S.-based service to view banned sites such as BBC News, MIT and Amnesty

But an independent report released Monday reveals that the U.S. government
also censors what Chinese and Iranian citizens can see online. Technology
used by the IBB, which puts out the Voice of America broadcasts, prevents
them from visiting Web addresses that include a peculiar list of verboten
keywords. The list includes "ass" (which inadvertently bans, "breast" (, "hot" ( and, "pic" ( and "teen" (  [...]

Politech mailing list Archived at
Moderated by Declan McCullagh (

Risks of prisoner abuse vs. digital cameras

<Lauren Weinstein <>>
Fri, 7 May 2004 08:23:31 -0700 (PDT)

Perhaps understandably lost in the furor over Iraqi prisoner abuse is the
role that technology has played in moving this story from "footnote" to
"international firestorm" status.  Without a doubt, the digital camera has
played a central role.

It's these relatively inexpensive cameras, producing vast numbers of
high-quality shots at essentially zero cost per photo, images that can be
easily stored and e-mailed, that have inspired the visual recording of
scenes that otherwise would have been reduced to dry, easily ignored,
textual descriptions at the most.

Note the brief, sterile, vacuous January press release from CENTCOM, that
Rumsfeld is touting as proof that everyone was already informed about
possible "detainee" abuse problems in Iraq: ( ).

Now contrast the stark, full-color realities of the photos, most from a
massive digital archive obtained by *The Washington Post* (and subjected to
"appropriate" cropping and blurring -- it's OK to show all manner of visual
horrors to the public, but you don't want to offend them with naughty body

The photos *are* the story, and apparently there are lots more to come.

President Bush says that such abuses are aberrations that don't reflect the
true nature of our society.  In the "Reality Reset" column referenced by
( ) I question this
premise, but without a doubt the digital camera and related technologies
are creating a sea change, the effects of which we cannot even begin to
realistically predict.

Lauren Weinstein   +1 (818) 225-2800

Auto-Blacklisting is a bad idea

<Drew Dean <>>
Thu, 06 May 2004 12:49:28 -0700 (PDT)

I recently received a challenge from someone's challenge-response spam
filter.  Alas, I had not sent the original message.  Unfortunately, said
challenge-response system warned that it was going to automatically
blacklist my e-mail address if I didn't respond.  But I didn't want to
respond, because the original message was either malware (most probably, see
below) or spam.

Milgram's famous "six degrees of separation" turns out to make
auto-blacklisting a really bad idea: many types of e-mail-based malware
propagate via random choices from the victim's address book.  As it's an
awfully small world, there's a good chance that someone knows two people
with common interests, who may not have exchanged e-mail before.  (Lots of
people seem to have my old e-mail address in their address books, even though
I've never heard from them, or sent them mail, other than indirectly via a
mailing list (or USENET posting).)

If auto-blacklisting challenge-responses systems become the norm, there will
be interesting risks related to the combination of forged mail, and
auto-blacklists: what happens if you follow the challenge-response protocol
to avoid being on someone's blacklist (the only obvious option), and said
person (e.g., your research sponsor) receives a highly inappropriate piece
of mail nominally from you?  Other denial of service attacks are also
possible: seed your competitors (auto-)blacklists with the e-mail addresses
of your (mutual) funding agency.  I'm sure the clever will have even more
ideas about risks here.

Auto-whitelisting, by contrast, has none of these problems.

Drew Dean, Computer Science Laboratory, SRI International

Re: Computer glitch grounds Atlanta flights (RISKS-23.35)

<Tron Smith <>>
Tue, 4 May 2004 19:47:14 -0700 (PDT)

Talk within the airline industry has it that Delta's problems on 1 May 2004
were the result of systems not patched and hit by the Sasser.b virus.

Corrupted virus definition load blocks re-load

<George Michaelson <>>
Fri, 7 May 2004 09:55:20 +1000

The desktop virus scanner we use appears to update windows registry, or some
other record of load, *before its verified the integrity* of the loaded virus
definitions. And, it refuses to re-load them if its recorded them as loaded.

We have just had at least one host which fell over during the virus load
phase off the net, and then spend an hour or more trying to find where to
remove on-disk data to allow a reload of the file.

The risk here is pretty obvious: a virus could quite easily be written to
corrupt the virus definition state in registry and prevent you from
downloading the current patches to remove the virus...

George Michaelson, APNIC, PO Box 2131 Milton QLD 4064 Australia  Phone: +61 7 3858 3150

Antivirus software prolongs viral life (Kuenning, RISKS-23.35)

<Matthias Heiler <>>
05 May 2004 09:56:54 +0200

> Clearly, the "System Restore" feature has not been carefully thought out!

"System Restore" is a functionality of Windows XP, not of any Antivirus
software.  So the header should read "Windows XP prolongs viral life".

Challenge/response standards

<Brent Laminack <>>
Wed, 5 May 2004 21:05:32 -0400

What is your favorite color? Blue.. No, Yellow! Aaaargh!!

Security professionals are well aware of password restrictions.  ISO 17799
says that passwords should be at least six characters in length and free of
consecutive identical characters or all-numeric or all-alphabetical
groups. (Section 9.3.1) There are a number of variations on the theme:
requiring internal numerics, mixed upper and lower case, etc.

Here is a recent encounter I had where an organization tried to apply such a
rule to a non-password.

I was signing up for on-line bill-payment from our local ILEC PSTN telephone
provider. I chose my user name and password, and was asked to provide a
question and answer to re-set my password. Such challenge/response systems
are fairly common. I liked that I could choose my own question. Some systems
have a small set of pre-defined questions that are, unfortunately, matters
of public record "What is your mother's maiden name?", "In what city where
you born?" etc. They suggested using a question like "What is your favorite
color?" I decided that that particular information was not easily found in
government databases so I entered it as the question. I then entered my
favorite color as the answer. I submitted the form and got an error message
saying that the answer had to be at least six characters.  Odd. Let's
see.. common colors of at least six characters: Blue? Red? Green?  White?
Black? Cyan? Beige? Aqua? Gray? Pink? Navy? Olive? Peach? Rose?  Tan? Teal?
Clearly they have disallowed a number of valid responses.  I finally picked
a compound color name (which really isn't my favorite color) and finished
the registration process.

What think ye? Is it proper to apply password standards to
challenge/response responses, or are other criteria (such as: not a matter
of public record) more valid? I've looked, but can find no body of work
setting forth standards for challenge/response questions similar to those
standards which govern password creation and use. Clearly, this should be
addressed if such challenge/response dialogs are used to reset
passwords. This because authentication by strong passwords is for naught if
the password reset mechanism is weak or flawed.

Aus vs. Swiss speeding (RISKS-23.35)

Wed, 5 May 2004 07:46:40 +0100

> The country is proud of its strictness in enforcing speed rules, sometimes
> fining motorists for driving one kilometer above the posted limit (however
> absurd that sounds).

That's a little ironic, given that I was twice fined in Switzerland for
"injuring the speed laws" by riding 1 km/h too fast, after a 5 km/h
tolerance (86 in an 80 and 56 in a 50; for completeness my other fine was
for four over at 59 in a 50 -- each fine was CHF 20 [since tripled] but no
points accrue in the Swiss system).

Ivan Reid, Electronic & Computer Engineering,  CMS  Collaboration,
Brunel University.   Room 40-1-B12, CERN

Re: ... lost revenue from faulty speed cameras (Meyer, RISKS-23.35)

<"Anthony Youngman" <>>
Wed, 5 May 2004 09:19:26 +0100

  "Last year their accuracy was questioned after reports that a truck with a
  maximum speed of 140 km/h was caught traveling at 164 km/h, and other
  similar incidents."

I don't know how failsafe the UK system is, but UK fixed cameras take a
double image with a time interval of maybe a second. Coupled with markings
on the road, it's possible to work out the distance covered between photos,
and hence calculate the speed. I'm fairly certain that on several occasions
this has been used to prove the camera was faulty.  The only thing I don't
know is how the time gap is proven -- hopefully the time is stamped on the
photo based on the national Radio Time Signal.

Re: ... lost revenue from faulty speed cameras (Meyer, RISKS-23.35)

<Michael Smith <>>
Wed, 05 May 2004 03:26

> The country is proud of its strictness in enforcing speed
> rules, sometimes fining motorists for driving one
> kilometer above the posted limit (however absurd that sounds).

That sounds like an extraordinary claim to me.  I've lived in Australia all
of my life (over 40 years) and I've never heard of a speeding ticket being
given for one km/h over the limit.  Speed cameras are normally calibrated
for between seven and 12 km/h above the limit.

As for "The country is proud of its strictness in enforcing speed rules",
I'm not sure how you would define "the country".  Most official sources
attribute a significant proportion of road deaths to excessive speed.  (e.g. and such sources
normally describe the anti-speeding initiatives as being successful in
reducing the number of road deaths.  However there is a quite vocal "pro
speeding" group.  I don't have data to estimate the group's size, but they
get significant media attention.  They claim that speed limit enforcement is
merely "revenue raising" (which is presumed to be a bad thing) and that
speeding has little effect on accident rates -- suggesting that road
improvements and driver training are preferable ways of reducing the number
of road deaths.

Mr Meyer's comments on the faulty speed cameras are, sadly, all too
accurate.  However I would be interested to know his sources on the comments
outlined above -- for they contradict my own personal experience.

Michael J Smith <>

Re: ... lost revenue from faulty speed cameras (Smith, RISKS-23.36)

<"Bertrand Meyer" <>>
Wed, 5 May 2004 07:25:51 +0200

I have been a frequent visitor to Australia (the equivalent of a month and a
half a year) for the past ten years and this may be the most dangerous
stage, at which you start believing that you know enough about the place
even if you're still basically a tourist.

Both of the claims that Michael questions are based on numerous
conversations with diverse people. The fear of being fined for going 1 KM/H
over the limit is prevalent among my acquaintances; As to being "proud" of
the policy this is a general impression, which may be biased by the kind of
people I meet -- typically, urban professionals.

This illustrates the risks of voicing generalities about "the country",
whatever that country is. Fortunately the other points in my note are, as
you observe, factual, not a matter of opinion or impression.

MDT and a Fatal accident: a possibility?

<"Nick Lindsley" <>>
Fri, 7 May 2004 00:10:50 -0400

  ---------- Original Message -------------
From: fist <>
Date:  Fri, 07 May 2004 11:04:39 +1000

>Nick, One suggestion would be to send a short version of this to the Risks
>Digest, asking if anyone had seen similar reports and pointing out the
>dangers of drivers not watching the road I find this digest has some of the
>most intelligent IT people around, and it might generate enough commentary
>to give you something more to send along to the authorities.  On 8 Sep
>2002, Wayne Duncan (a colleague of mine) rolled his taxi with fatal
>results on Airport Drive, Brisbane. It was unwitnessed and skid marks
>indicated that he had swerved, possibly to avoid something in his way.

For sometime before and after this accident, I had considered the
possibility that using and reading the on-board computer system could
contribute to an accident. It had nearly happened to me, looking up just in
time to avoid a pedestrian. Wayne was not a bad driver, not always within
the speed limit, but not outlandishly beyond it either.

Black and White's taxi computer system is supplied by and maintained online
by Raywood Communication of Melbourne, and works in conjunction with a GPS
in the taxi which transmits its position (latitude and longtitude) and other
relevant data to the cab base.

I figured that if I knew the position of the crash by driving to the
accident site and using my own GPS, I could perhaps find out if it coincided
with the last transmission from Wayne's taxi, proving at least the
possibility that he had been using the on-board computer close to the time
of his death. After perhaps three months I visited Const Kelly Donahue at
Boondall Police Centre, who was investigating the cause of the crash. I
explained how we physically worked the on-board computer, roughly measured
time with eyes off the road, reaction time, distance traveled therein and so

As stated previously, Wayne's accident was unwitnessed. As luck -- if that's
the word -- would have it, the first person on the scene was a doctor who
declared him dead at 20:44. He probably had been killed instantly.

Constable Donahue had a report from Black and White purporting to have come
from Wayne's taxi timed at 20:40 (about 4 minutes before he was found dead),
and printed shortly after the accident (I am not sure when or by whom).

At that time, according to the report, Wayne had indicated his preferred
work area as Eagle Farm and other details. Most interesting for me was the
latitude and longtitude. I was looking for something close to 27deg 23.6mins
South and 153deg 06.8mins East (about 300 to 400 metres before the tall
control tower on the way to the Domestic Airport), roughly the site of the
accident and marked nowadays by two small white crosses in the median

Everything appeared to be in order EXCEPT for the latitude and longtitude.
This indicated a position 1400 kms to the SW, near Melbourne, approximately
38 deg South and 145 deg East. When I pointed this out to Const Donahue she
had no explanation. In fact she had been unaware that the report contained
the current position of the taxi when it transmitted details at 20:40 even
though she had been in possession of the report for some months.

Now this could be seen as another simple computer glitch. Having an IT
background and having spent many years using GPSs for navigating boats, I
find this extremely unlikely. After all, everything else transmitted from
the taxi to the cab base at 20:40 appeared correctly, so why not the
latitude and longtitude? Const. Donahue had no explanation.

Now over one year later I am still without an explanation. I have repeatedly
asked the police, the coroner, offered my own experience, just to be
basically ignored. I have even had the Freedom of Information act mentioned.

Recently Constable Donahue phoned me from Landsborough, her new posting, to
tell me that the coroner has decided not to have an inquest into the
accident.  I may not in fact have a right to know exactly what the reason
for the false latitude and longtitude on the report was. My main concern is
that the police and/or coroner are acting on the advice of B&W and Raywood
Communications who obviously have an invested interest in a non
controversial outcome. Additionally, if the position in the report was
wrong, has the real position been saved? And was it close to the accident


There will be no inquest and I have received copies of the police report and
witness statements.  The following is a copy I have just sent to the Deputy
Coroner here in Brisbane:

  C A Clements
  Deputy State Coroner
  179 North Quay
  Brisbane 4000
  Your Ref#COR 472/02

  30 April 2004

  Dear Mr/Ms Clements

  Thank you for sending me some of the details concerning the fatal accident
  to Clifford Wayne Duncan at Airport Drive, Brisbane Airport on the 8
  September 2002.

  As you are probably aware, I knew Duncan on a passing basis and I was
  curious why a driver with his experience would suddenly swerve to the
  right through about 170 degrees, initiating a roll that killed him when
  his taxi collided with a steel pole.  I had considered the possibility
  that his on-board computer (and back lit at the time 2041hrs) had
  distracted his eyes a moment too long, and when he looked up he
  desperately -- and suddenly -- swerved to avoid something in his lane
  (possibly a fox or another car).  Unfortunately too late.

  Having read the reports and witness statements that you sent me, I am still
  unconvinced that the on-board computer was not a contributory factor in the
  accident.  I noticed towards the end of Report Number 02/22444, Senior
  Constable Donohue recommended (and I quote from page 11):

  ``1. that Queensland Transport conduct a safety audit into the feasibility
  of taxi drivers operating the MDT safely whilst the vehicle is in motion.
  The operation of the MDT whilst the vehicle is moving may be akin to the use
  of mobile phones.''

  It is the only recommendation that she makes.

  On page 9 of the same report she mentions in further information 1(b):

  ``I visually observed each of the drivers to take their attention from the
  road ahead for a period of at least 2 seconds at a time.  Furthermore,
  conversations with the Black and White taxi drivers suggested that they are
  all of the opinion it is a safety risk, as monitoring requires the driver to
  take his/her eyes away from the road ahead, relying on peripheral vision.
  This risk was particularly enhanced during nighttime hours, as the
  illumination of the MDT was distracting when trying to refocus ahead.  They
  all likened the operation of a MDT to a mobile phone.''

  The Statement of Witness Greg Whitney (Service manager for Raywood
  Communications at the time of the accident) contains an analysis of how the
  GPS/On-board MDT work.  Page 4 of that witness' statement contains the

  ``I have an MDT and radios fitted to my vehicle for testing purposes.  I
  admit that in times past, I have been accessing the data screens whilst
  driving.  When I have looked up, I have been surprised at how far I have
  traveled and admit that if a car was slowing down or stopped in front of me,
  or a pedestrian was to walk in front of my vehicle, my ability to stop
  safely may have been compromised.''

  Coming from the manufacturers themselves, this is rather significant.

  Mr Whitney also mentions a software engineer with Raywood called Karl Leake
  (now based in North Sydney).  On the report given to the police, the current
  location of Duncan is given in and around Melbourne (an error offset 1400km
  south west of the actual position).  I discussed this matter with Mr Leake
  and Mr Whitney today and it appears that this ``error'' is well known
  and deliberate and used for their ``own internal purposes''.  Neither
  could explain why this known error would be maintained in software that had
  been in use for some years with B&W Brisbane.  Interestingly, Mr Leake told
  me that the actual correct position would have stayed on B&W hard disk as
  the ``error'' is only induced by the report generator.  In theory the
  correct position should still be on B&W's computer system unless it has been
  deleted.  Considering the severity of the accident, one can only hope that
  it hasn't been deleted as it will show quite conclusively where the Wayne
  Duncan was at 2041 hrs on the day he died -- and, more importantly, if he was
  closing in on the accident site ( 27 23.6South 153 06.8East).  He would
  probably been looking at the screen just after his final transmission at
  20:40:09 hrs to check the stats.

  I do not know if you felt a need for an independent technical witness
  (unrelated to the companies involved) but, considering the importance of the
  matter (it could happen again, if it happened at all) why will there be no
  inquest?  Is it because you feel that there is absolutely no chance that the
  on-board MDT computer system contributed to the accident, and if so, where
  is the evidence for that side of the argument?

  Additionally, I would like to request copies of the following:

  Data Printout for B&W Taxi #682 for the 8 Sept 2002
  Data Printout for Statistics for B&W taxi #682 for 1 Sept 2002 thru to
  (and including) 8 Sept 2002.

  Yours Sincerely
  Nick Lindsley

Thank God for cut and paste.

I have been around all the state govt houses -- police, transport, justice
and, it seems, I am going around in circles.  I am not 100% exactly how the
driver was killed, but I do think the subject needs further attention.

Interestingly, I belong to a Yahoo discussion group (Oz Cabs) and I put a
post on this issue about a year ago to try an engender some interest in the
matter.  Yesterday the moderator -- a David Gawthorn (Melbourne) -- e-mailed
to say that someone in Qld had called him to "moderate" my posts on this
particular subject ("moderate" in this context means censor) quite a few
months ago.  I also cannot find my original posting.

If you find this interesting, please contact me on 0418-727.727 Australia

Please report problems with the web pages to the maintainer