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 17 Issue 4

Thursday 6 April 1995


o Thoughts on SATAN, Michelangelo and Crack
Tom Perrine
o A possible "solution" to Internet SATAN: Handcuffs
o Make a Call, Turn Off the Power
Mike Winkelman
o Boeing 777 has dainty feet
Nathan Myers
o Risks of HCI designed by non-typist
Pete Mellor
o Endless loops in Voice Mail
Dick Mills
o Computer will control Nick Ingram's execution
Mike Wilson
o "Airport Vending Machine Sells Computer Programs"
Barry Jaspan
o Computer Security's an Oxymoron
o Re: Complexity
Stephen L Nicoud
o RISK of webpage rating system
Joan Combs Durso
o Chunnel as a Theme Park (Re: Ghost trains)
A. Padgett Peterson
o Insecurity over ATM security
Jon Green
o Safeware: System Safety and Computers
Nancy Leveson
o InfoWarCon '95, First Call for Papers
Winn Schwartau
o Info on RISKS (comp.risks)

Thoughts on SATAN, Michelangelo and Crack

Tom Perrine <tep@SDSC.EDU>
Tue, 4 Apr 95 21:40:39 PDT
Well, here it is, only 10 hours until the Internet As We Know It will grind
to a halt.  Of course, the Imminent Demise of the 'Net has been predicted
before.  In fact, this will be at least the fifth time that I have
personally witnessed such mass hysteria and overzealous concern over the
"safety and integrity" of the Internet.

There has been so much hype over the release of SATAN, including articles in
the New York Times, fer cryin' out loud, that entirely too many people have
no idea what is going on, but They Are Sure That Truly The Sky Will Fall.

It is very strange, and somehow wonderful, that our society finally has
enough people with some knowledge of the Internet, that they could even care
about the integrity of the Internet.  It is also, however, sad that they do
not understand that thing which they use every day, and have come to depend
on so much.

What is the truth behind the hype?  Will SATAN be the ultimate "cracking"
tool?  Is it the network equivalent of an unstoppable skeleton key?

Of course not.  SATAN is nothing more than a software implementation of a
checklist of well-known flaws in the design and/or implementation of the
UNIX operating system and its network servers, and Internet protocols.
There is nothing in SATAN that hasn't been seen in at least a dozen
intrusion attempts in the last year.  The holes examined by SATAN have been
known to the cracker community for years in most cases.

Does this mean that the release of SATAN is unimportant?  That all the hype
and publicity has been a mistake?  That there is no reason to worry?

Again, of course not.  After the Michelangelo virus media "event" of a few
years ago, the computer world breathed a huge sigh of relief.  The
predictions were that between 15 and 50% of the world's personal computers
would be destroyed by Michelangelo.  This obviously didn't happen.  True,
most estimates of infection rates were obviously out of line.  But a
significant number of companies and individual users reported that due to
the media blitz, they now took virus protection seriously, and almost
everyone admitted that they scanned their systems for virii in the weeks
before Michelangelo was due.

SATAN will be important for the same reason that Michelangelo and Crack have
been important: they have raised the issue of computer security in a way
that cannot be ignored, and they have given harried system and network
administrators some of the same tools already in use by cracker.

Sites that used to be able to ignore the risks of connecting to the
Internet, who believed that they were immune, too low-profile, of just
didn't understand now know that they *must* take steps to protect

With the certain knowledge that SATAN (and other tools) are out there, being
susceptible to well-known attacks clearly shows a lack of "due diligence",
which a term which courts and juries seem to understand.

Now that SATAN is out, any commercial site that is cracked may find itself
involved in legal action from its users and customers.

There is considerable belief (one might also suggest consensus) that the
availability of Crack has forced sites to use non-dictionary passwords.
Since Crack became available, the "cracking" of passwords from stolen
password file has almost completely disappeared from the Internet.

SATAN will level the playing field, as now system administrators who things
to do other than write custom cracking packages will have the same tools as
the "black hats".

I hope that the release of SATAN will encourage vendors to increase the
security of their shipped products, and raise the level of security
awareness throughout the Internet.  Just by existing, it will, after a time,
improve the integrity of the 'Net as we now know it.

But for the next few weeks, "let's be careful out there."

Tom E. Perrine (tep@SDSC.EDU), San Diego Supercomputer Center
+1.619.534.510  FAX: +1.619.534.5152

A possible "solution" to Internet SATAN: Handcuffs

<[address withheld by request]>
Wed, 05 Apr 95 10:00 xxT
     The authors of the recently released SATAN package for probing Internet
sites have shown a level of amorality that should gladden the hearts of the
National Rifle Association and arms merchants around the world.
     By close analogy, SATAN's parents' attitude appears to be that it's
perfectly OK, perhaps even admirable, to go from house to house without
permission trying each door and window to see if it's unlocked, or perhaps
not locked securely enough.  If caught inside, the intruder would of course
claim he or she was just performing a "security check", and gee whiz, that
homeowner REALLY should buy a better lock!  Bull****.
     That sort of argument wouldn't wash with unauthorized residential
probing/entries/burglaries, and it shouldn't be acceptable for such
unauthorized activities when directed against computer systems either.
     Up to now, most system administrators have tended to take a fairly
permissive attitude towards hacking probes/attacks--at least the first time.
Usually the farthest they go is to warn the offending users and/or system
administrators at the site originating the attack, and let it go at that.
The time has come for this attitude to change.
     It's time for it to be made clear in no uncertain terms that any
unauthorized probing cases will be immediately turned over to law
enforcement for appropriate criminal and/or civil actions whenever possible.
A variety of laws would appear to make it illegal to use SATAN or similar
tools against a site without that site's permission.  Most likely there are
a number of cyber-lawyers who could do quite well specializing in this area.
     Where attacking users can be identified, enforcement can be directed
towards them.  Where sites are unable or unwilling to cooperate in
identifying the user, then action may have to be taken against sites where
attacks originated as well.
     It is perhaps unfortunate that this sort of "no more excuses" policy
will probably net a large number of rather ignorant users who run tools like
SATAN "for fun" while oblivious to the logging, tracking, tracing, and other
countermeasures that exist against it.  But that's the price they'll have to
pay for playing with powerful tools left laying around by amoral software
     Playtime is over, kiddies.

       [Don't forget, SATAN runs as root — although that is not
       necessarily an obstacle for many folks, and some of it can
       be hacked to run unprivileged.  But breaking root in the
       first place falls into the "unauthorized" category.  PGN]

Make a Call, Turn Off the Power

Mike Winkelman <>
Wed, 5 Apr 1995 16:56:47 -0400
I suppose I shouldn't be surprised, but the power went out for 17,000 here
in our small town (38,000) last week.  The local newspaper first reported
that the power company didn't know why it went out, but that it "may be
related to someone digging in their back yard".  A week later they fixed the
blame.  A phone call (by the power company), supposedly to one substation,
(completely automated judging by the tone of the article) went instead to a
different substation (for unexplained reasons) and shut that substation
down. It was down for 1.5 hours.

The risks??  Just think of a few well placed calls by non-power company
people to major metropolitan areas in the dead of night if they have similar

Boeing 777 has dainty feet

Nathan Myers <>
Tue, 4 Apr 1995 23:38:16 -0700
I have heard recently that the new Boeing 777 jetliner, described
in recent news reports as "skating through the approval process",
has a little problem that might be interesting to RISKS readers.

It seems that an important part of the landing gear is too weak, and will
get "used up" (through metal fatigue), and need to be replaced annually.
While this is probably not a safety problem, it's an extra expense (frequent
inspections and replacements) and an embarrassment.

Unfortunately, fixing it isn't just a matter of making the part stronger; it
would then be bigger and heavier, affecting fit, balance, and nearby parts.
This sort of problem is familiar in the "shakeout period" of all previous
jetliners, but it's surprising that it showed up so late in the approval
process.  (A previous 7?7 has a nonlinearity in the landing gear linkage
that caused an oscillation when trying to close the doors; it was fixed by
an appalling hydraulic "patch" that cancels feedback during the nonlinear
portion of the cycle.)

How did this mistake get all the way through Boeing's legendary engineering
process?  The 777 is the first commercial Boeing to have been modeled
entirely on computer before construction.  Apparently the part is precisely
a factor of two weaker than it should have been.  Does this smell like a
structural model entry error?  I have been unable to find out more about the
source of the error, and would welcome more detailed information.

Maybe the RISK is in streamlining your engineering process so well, and
eliminating so many of the more common mistakes that would have caused
delays, that you are already getting final FAA approval before the booboos
that only time can reveal are noticed.  Or maybe the RISK is just that
better communications can leak word of embarrassments few would have known
about otherwise.

Risks of HCI designed by non-typist

Pete Mellor <>
Tue, 28 Mar 95 15:45:14 BST
The Management and Administrative Computing Initiative (MACI) is an attempt
to get all universities in the UK to use the same computer package for their
administrative operations. (In fact, it has been found necessary to define
four "families" of universities with similar approaches, and design a
package for each family.)

The requirements specification, design and gradual implementation of the
MAC packages is proceeding. The following anecdote might amuse readers of
RISKS who take an interest in Human Computer Interface design.

The part of the MAC package which deals with job applications in a certain
university (which shall remain nameless) has had an interesting little
"feature" incorporated into its HCI by one of the implementors (who has since
moved on to pastures new). To save the effort of the typists in keying
data into a name or address field, he arranged that letters could be typed
in upper or lower case anywhere, and on input the case would be changed so
that initials and the first letter of each word would be capitalised, and
the remainder put into lower case.

To a two-fingered typist like him, this probably seemed like a great
labour-saving idea. For a trained touch typist (such as my informant) it
saves nothing, of course. Not only that, but responses to applications are
now being sent to "Dr. B. O'malley, University Of Newcastle-Upon-Tyne".

Lessons for HCI design would seem to be:-

1. Write a specification.

2. Get someone else to read it before implementation.

3. Better still, get the feedback from the use of a prototype.

4. If you want to know the user's requirements, ask the user!

The costs of getting a different person to remove the feature, and of
cleaning up the database, are still being counted!

Peter Mellor, Centre For Software Reliability, City University, Northampton
Square, London Ec1v 0hb  +44 (171) 477-8422, Fax.: +44 (171) 477-8585,

Endless loops in Voice Mail

Dick Mills <>
Tue, 04 Apr 1995 11:53:17 -0400
I just called someone at "XX" Software Inc. He told me he would be at
extension 126.  Here's an abbreviated transcript of what I heard.

   [Hmmm. It is in a loop.  What if I dial '0'?]
   [Hmm.  Didn't work.  Hang up and dial again.]
   [Sigh, hang up]

So what's the risk?  We have been conditioned to think of telephones
as non-programmable devices.  So when we purchase a new phone system
which is programmable, we may neglect applying the same quality
assurance to phone programming as we [hopefully] do to normal

A good way to avoid the trap is to inventory your belongings.  Which
things do you own that are actually dumb, purportedly dumb, or
traditionally intelligent?  Presumably you know how to deal
with the first and last.  Now think carefully about the middle ones.
Are you treating them with proper lack of trust?

Computer will control Nick Ingram's execution

"Mike Wilson, ICL Medical Portfolio" <>
Thu, 6 Apr 1995 11:25:07 +0100 (BST)
>From "Today" newspaper, London, England, 6 April 1995:

    Nick Ingram's execution will be controlled by a computer.
    It is the first of its kind and follows a series of electric chair
    bungles where condemned men survived a manually controlled surge.
    Three executioners will each push a button to activate the computer
    but only one is "live", leaving none of the trio knowing if he started
    the deadly process.
    The computer will then take 30 seconds checking every connection to
    Ingram's head, legs and arms and, if there are no problems, will send
    2,000 volts slamming into his body for four seconds.
    It then switches the current to 1,000 volts for seven seconds and 208
    volts for two minutes.
    Throughout the execution, the computer's systems monitor the current,
    making sure there is no drop in power.
    Five minutes from when the current is stopped, a doctor will pronounce
    the Briton dead.

The risks are horrifying.

Mike Wilson                            
ICL Medical Portfolio, Kings House, Kings Road, Reading, RG1 3PX, UK

   [Sure gives a new meaning to volt-tolerant systems.  PGN]

"Airport Vending Machine Sells Computer Programs" (AP)

"Barry Jaspan" <>
Tue, 4 Apr 1995 17:13:11 -0400
An recent AP article describes a prototype vending machine installed
at the Raleigh-Durham International Airport.  The machine sells
shareware.  A customer inserts a floppy disk, selects a program,
inserts money, and out pops the disk with the software installed.

I suppose that the RISKS are really no different than when retrieving
software over the network, and practically is not as big a problem since far
fewer people will use it.  Somehow, though, the thought of a row of machines
at which I can buy Camels, Coke, Snickers, and Tetris makes me shiver.

Barry Jaspan

Computer Security's an Oxymoron (Edupage 4 April 1995)

Edupage <>
Tue, 4 Apr 1995 23:47:21 -0400
Computer break-ins are still on the rise, often accompanied by significant
financial losses.  The Computer Emergency Response Team's manager says the
number of reported violations was 130 in 1990, 800 in 1992, 1,300 in 1993
and 2,300 in 1994.  A 1994 survey by Ernst and Young of more than a thousand
companies showed 20% reporting financial losses as a result of computer
break-ins.  An earlier study by USA Research cited losses of $164 million in
1991 due to unauthorized intrusions.  (Technology Review, April 1995, p.33)

Re: Complexity (English, RISKS-17.03)

Stephen L Nicoud <>
Thu, 6 Apr 95 10:38:09 PDT
   (it could be argued, for example, that air travel is currently too
   safe, because the close attention to safety raises the cost of
   short-haul flights and encourages people to drive instead)

Citing Paul Russell (Chief Engineer, Boeing Airplane Safety Engineering) an
August 18, 1994 article in The Aviation Daily reported that the "jet
transport accident rate plummeted between 1959 and 1975 but has been fairly
flat since then...".

"With more and more traffic looming in the future ..." there is "a
projection of one jet transport hull loss per week by the year 2010".

A hull loss is airplane damage which is substantial and beyond economic

Stephen L Nicoud  <Stephen.Nicoud@Boeing.Com>  [Disclaimers...]

RISK of webpage rating system

Joan Combs Durso <>
Wed, 5 Apr 1995 14:48:00 -0400
The only objection I can think of to the proposed system of sorting possibly
objectionable material according to "over13" and etc is this: one of the
current justifications for NOT regulating the adult material is that it
takes some looking to find it.  The proposed rating system would seem to
make such materials readily identifiable via searching, thus pointing out
for all the world the locations of this material, and making it easier for
kids using unrestricted browsers to find.

Joan Combs Durso, Penn State Great Valley

Chunnel as a Theme Park (Re: Ghost trains, Wodehouse, RISKS-17.03)

A. Padgett Peterson <>
Tue, 4 Apr 95 14:29:01 -0400
This happened to my wife a couple of weeks ago & she said some passengers
became somewhat frantic looking for rising waters - officials did come
around giving out coupons for a half price repeat trip if taken within two
months - Universal Studios did something similar when it opened and the Jaws
ride did not work.

The real RISK will occur if (when) a driver ignores a real signal.


Insecurity over ATM security

Jon Green <>
Thu, 6 Apr 1995 16:20:59 +0100 (BST)
My local branch of the Midland Bank has just upgraded its ATM (automatic
teller machine - hole in the wall cash dispenser).  The old unit had a
central keypad, and a green screen with a filter which restricted the useful
angle of vision to about ten degrees either side of dead-in-front.  The
screen was positioned to the left of the machine, making it easy to block
almost the whole arc and it was not readable from more than about 5m away.
You could prevent all but the most persistent shoulder-hanger from seeing
your PIN being entered, and your balance when it came up on the screen, by
interposing your body.

The new box features a nice bright colour screen and flashing lights to
point you to the next bit of the ATM to look at (card slot, cash slot and so
forth).  Unfortunately, the nice bright screen is visible clearly from about
10m or more away, over an approximate 90 degrees of arc at least.  To make
things worse, the keypad is placed to the left of the machine, so that 90%
of the population is left to dial in their PIN slowly and laboriously with
their wrong hand.  Oh, and the keys are so stiff that anyone standing to the
right of the machine could not hope to avoid being able to read off the PIN
as it is stabbed in.  The final insult is that - like former machines from
the same bank - the balance is shown on-screen only.  No option to print it
out instead.

What a disaster!  The RISKS abound - PINs are highly visible from an
adjacent position, all on-screen transactions are highly visible over a wide
area and there is no option to check your balance in privacy.  The only
consolation is that, in sleepy Diss, a mugging would be the talk of the town
for months.

I had a word with the branch manager.  Apparently, these machines are
replacing existing units everywhere in the UK in a rolling upgrade
programme.  He conceded the security problems - reluctantly, after a
predicatable comment that, "They must have looked into the security aspects

I suggested that both (1) an arc-restricting filter be added, and; (2) the
firmware be altered to allow an option for balances to be printed only,
rather than displayed.  I get the impression that the "Listening Bank" will
quietly file the suggestions in the round file.                Hyphen home page:           And mine:

Safeware: System Safety and Computers

Nancy Leveson <>
Tue, 04 Apr 1995 10:13:10 PDT
NEW BOOK-- Safeware: System Safety and Computers, by Nancy G. Leveson,
  University of Washington (, Addison-Wesley,
  ISBN: 01201-11972-2, $49.50.

This book examines past accidents and what is currently known about building
safe electromechanical systems to see what lessons can be applied to new
computer-controlled systems.  One lesson is that most accidents are not the
result of unknown scientific principles but rather of a failure to apply
well-known, standard engineering practices.  A second lesson is that
accidents will not be prevented by technological fixes alone, but will
require control of all aspects of the development and operation of the
system.  The features of a methodology for building safety-critical systems
are outlined.

PART 1: The Nature of Risk (126 pages)
   Is there a problem?
   How safe is safe enough?
   The role of computers in accidents
   Software myths
   Why software engineering is hard
   Problems in ascribing causality
   A hierarchical model of causality
   Root causes of accidents
   Do humans cause most accidents?
   The need for and role of humans in automated systems

PART 2: Introduction to System Safety (50 pages)
   Foundations of system safety (systems theory and systems engineering)
   Historical development
   Basic concepts (hazard analysis, design for safety, management)
   Software system safety
   Cost and effectiveness of system safety
   Other approaches to safety (industrial engineering, reliability engineering)

PART 3: Definitions and Models (75 pages)
   Accident models
   Human task and error models

PART 4: Elements of a Safeware Program (290 pages)
   Managing safety (the role of management, setting policy, communication
       channels, setting up a system safety organization, place in the
       organizational structure, documentation)
   The system and software safety process (general tasks, real examples)
   Hazard analysis (what it is, how to do it, types of models, types of
       analysis, current models and techniques, limitations, evaluations)
   Software hazard analysis and requirements analysis
   Designing for safety
   Design of the human--machine interface
   Verification of safety (testing, software fault tree analysis)

APPENDICES:  Detailed descriptions of well-researched accidents along
with brief descriptions of industry-specific approaches to safety (132 pages)

  A. Medical Devices:  The Therac-25 story

  B. Aerospace:  The civil aviation approach to safety, Apollo 13, DC-10,
     and Challenger

  C. The Chemical Industry: The chemical process industry approach to
     safety, Seveso, Flixborough, and Bhopal

  D. Nuclear Power: How a nuclear power plant works, The nuclear power
     approach to safety, Windscale, Three Mile Island, and Chernobyl

InfoWarCon '95, First Call for Papers

Mon, 3 Apr 1995 22:12:13 -0400
                        InfoWarCon '95
       A 2 Day International Symposium on Information Warfare
                      September 7-8, 1995
                   Stouffer Concourse Hotel
                        Arlington, VA

                        Presented by
             National Computer Security Association
               Winn Schwartau and Interpact, Inc.
                   Robert Steele and OSS, Inc.

For Call for Papers or further information, contact

  National Computer Security Association
  10 South Courthouse Avenue
  Carlisle, PA 17013
  Phone 717-258-1816 or FAX 717-243-8642
  CompuServe:  GO NCSAFORUM

  Winn Schwartau Interpact, Inc.
  Information Security & Warfare
  V:813.393.6600 F:813.393.6361
  Email: Winn@Infowar.Com

Please report problems with the web pages to the maintainer