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 16 Issue 78

Thursday 2 February 1995


o Novel form of interference
Mich Kabay
o Attack on glasfibre cables causes Lufthansa delays
Klaus Brunnstein
o Anonymous ?? Survey
Dave Moore
o Deep Faults with NYNEX default?
Edward P Ravin
o Nynex glitch lets Call ID work even if blocked
Dick Mills
o "Protect Your Privacy" by Stallings
Rob Slade
o Identification technologies
Phil Agre
o Automatic file downloads in Seyon
Bruce E. Wampler
o Announcement of new mailing list on ethical issues
Bashir Jiwani
o CFP: 3rd International Workshop on Feature Interactions
Nancy Griffeth
o Info on RISKS (comp.risks)

Novel form of interference

"Mich Kabay [NCSA Sys_Op]" <>
31 Jan 95 11:22:34 EST
An amusing tidbit on unexpected risks of technology:

The Reuters news wire reports on an odd form of interference from
cell phones and pagers:

    RTw  01/30 0425  Israeli rabbi pulls plug on cellular phones

    JERUSALEM, Jan 30 (Reuter) - An Israeli rabbi has banned cellular
    telephones and pagers from synagogues, saying they interfered
    with worshippers' communication with God.

    Rabbi Mordechai Eliahu, a renowned sage and a former chief rabbi
    of the Jewish state, published the edict on Monday.

Interestingly, the cell phones are called, "Miracle Phones."

Maybe G-d needs spread-spectrum channels.... <g>.

M.E.Kabay,Ph.D., Director of Education, NCSA (Carlisle, PA); Chief Sysop,
NCSA CompuServe Forum, Mgmt Consultant, LGS Group Inc. (Montreal, QC)

Attack on glasfibre cables causes Lufthansa delays

Klaus Brunnstein <>
Thu, 2 Feb 1995 10:38:43 +0100
Unknown attackers interrupted, Wednesday Feb.1,1995, 7 glas fibre cables
near Frankfurt/Main airport. As parts of the cables were cut out, about
15.000 telephone lines were interrupted. The cables also carried data for
Lufthansa's booking computers; consequently, new reservations had to be made
manually.  As Lufthansa's main computers (installed at Frankfurt airport)
were cut off for some time, delays of up to 30 minutes were caused.
According to diverse German media, police has no information about
backgrounds of this criminal attack.

Klaus Brunnstein (February 2,1995)

Anonymous ?? Survey

Tue, 31 Jan 95 21:44:00 -0500
I was recently asked to participate in an opinion survey feedback to
management in order for them to compare their own views, superior views,
peer views, and subordinate views.  This data is then to be used by the
reviewee as a self improvement tool.

In order to get honest feedback, a commercial P.C. software package
called "2020" was used as a survey tool.  This package is supposed to
protect your anonymity.  It also uses a user supplied password on each
diskette to prevent anyone reading your responses.  The responses are
then collected by a master program and combined with everyone else's
responses.  Only the combined result is seen, individual responses are
not ever seen or tracked.  At least, that's the theory.

Since privacy and encryption have been a long time interest of mine, I
decided to take a look at the files.

The first thing I saw was that both my name and my reviewee's name were
embedded in the data area.

The next thing I saw was that free form comments were stored in clear ascii.
You lose the formatting, but any file viewer could see the comments.

I used a hex editor to change some of the comments then reinvoked the
program to see if it would detect the changes.  It never noticed a thing.
It obviously didn't use a digital signature or even a simple checksum.

The cherry on top was the password.  It only uses 0-9 & A-Z (uppercase).
The password was stored encrypted: down-1 and backward.  Thus a password of
"simple6" was stored as "5DKOLHR".  This took me all of the commercial
breaks while watching Star Trek Voyager to find and figure out.

The net result was that I chose not to participate in the anonymous feedback

Deep Faults with NYNEX default?

Tue, 31 Jan 1995 22:42:54 EST
Today I received an interesting letter from NYNEX (nee NY Telephone,
the local telephone service provider in NY City):

  Our records indicate that you requested All-Call Restrict Service on your
  telephone line...

  During a recent system check, we discovered that All-Call Restrict Service
  was not in place on some lines which it had been requested.  We are in the
  process of checking every All-Call Restrict line and correcting this
  problem where it exists.  As soon as we complete the checking and
  correction process, we will confirm the status of All-Call Restrict on
  your line through a special notification.

In other words, you might have thought you had Caller-ID disabled when you
make calls from your line, because you ordered it and NYNEX sent you a
confirmation notice six or seven months ago, but unless you independently
verified that it was in place, you might have been sending your number all
this time.

I can tell whether my line is sending caller-ID because I can call a friend
with a display and ask him.  But as usual, there is no way the local telco
can tell you what your lines settings are.  Call the billing office, and
they will describe what you have ordered and what was reported to have been
installed, but what is actually on the line?

It would be nice if you could dial a number and have a voice robot read back
to you the settings actually in place -- surely this is possible with
today's digital exchanges, if anyone thought to implement it.  Given how
many different settings you can have with today's phone lines in the USA
(call forwarding, speed dialing, send or don't send Caller ID, choice of
long distance carrier, etc), we already need it.

Nynex glitch lets Call ID work even if blocked

Dick Mills <>
Wed, 01 Feb 1995 08:19:53 -0500
So reported the Schenectady, New York Gazette on 2/1/95.  The report said

   Now, [Nynex] has discovered that All-Call Restrict feature doesn't
   always work.  "The company is indicating to our staff that roughly
   between 10 percent and 15 percent of people who believe they have
   All-Call blocking may have a situation where it doesn't work."

   That means as many as 82,500 people's numbers are being divulged
   when the think those numbers are being blocked.

   Nynex officials say they are investigating the problem and
   should have a cause identified sometime next week.

   "After this, one of the important things we'll do after we
   identify the cause is implement new processes that will prevent
   this from happening again."

   New England Telephone, Nynex's subsidiary, is checking to make
   sure its call blocking is working.

   The problem was revealed by an Albany man who depends on
   anonymity for hit livelihood.  He tried for weeks to convince
   Nynex that his call blocking was not working, only to be told
   it was.  Eventually [the man] took his story to the local press.

   The company's routine maintenance tests in its 600 central
   switching offices hadn't discovered this glitch.

To me the risk here is the arrogance that allows people to argue that such
large complex, distributed systems can ever be built flawlessly.  Any claim
that the system will always protect the customers privacy is fatuous.  It
happened already and it will certainly happen again sometime somewhere.

Dick Mills  Power Technologies, Inc.  P.O. Box 1058  Schenectady, NY
12301-1058      +1(518)395-5154

"Protect Your Privacy" by Stallings

"Rob Slade, Social Convener to the Net" <>
Thu, 02 Feb 1995 12:47:47 EST
[It didn't start out this way, but this seems to be the start of a "mini"
series of reviews on the topic of PGP.  Garfinkel's review is due to be sent
in another two weeks, Schneier's a week after that; Peachpit has one due
out in February while Zimmerman's own, I found out yesterday, is due out
in April. - rms]


"Protect Your Privacy", Stallings, 1995, 0-13-185596-4, U$19.95
%A   William Stallings
%C   113 Sylvan Avenue, Englewood Cliffs, NJ   07632
%D   1995
%G   0-13-185596-4
%I   Prentice Hall PTR
%O   U$19.95 (515) 284-6751 FAX (515) 284-2607
%P   302
%T   "Protect Your Privacy"

This is the first-released of at least three books on PGP (Pretty Good
Privacy), the encryption and authentication package by Phil Zimmerman.  It
covers the concepts of encryption, public key encryption, authentication and
key management, as well as the installation and operation of PGP on MS-DOS and
Macintosh platforms.  There is also some overview of front end shells for DOS
and Windows, plus helpful supplementary information on password/phrase choice
key servers, and where to get PGP.  (The promise of coverage for Windows, UNIX,
OS/2 and Amiga in the promotional literature is overkill, but these interfaces
will be almost identical to those covered.)

Stallings' material is generally very clear and well written.  Many times,
however, concepts are introduced early in the book but not explained until much
later.  This is particularly true of key management.  In most cases, I can
assure the reader not to worry--all will be made clear, eventually.  (In some
few cases, the explanation may remain confusing until you actually run the

The book echoes the assertion by many that PGP has become the de facto standard
in Internet privacy and authentication.  Certainly no commercial product has
anything like the same range of use.  Full acceptance of PGP, though, has been
hampered by the version incompatibilities and the legal difficulties caused by
the US weapons (!) expert control laws.  Given the touchy nature of this
subject, it is not terribly surprising that both Stallings, and Michael Johnson
in the access document, comment only briefly on the subject.  These passages
are somewhat calming, but hardly calculated to inspire confidence.

Solid background on the technology, if sometimes disjointed.  Terse, but
serviceable documentation on the program.  Readable and informative.

copyright Robert M. Slade, 1994   BKPRTPRV.RVW   941214

Vancouver Institute for Research into User Security Canada V7K 2G6

Identification technologies

Phil Agre <>
Wed, 1 Feb 1995 20:39:50 -0800
The journal "Information Technology and People" has just published a special
issue, edited by Roger Clarke <> entitled
"Identification Technologies and Their Implications for People".  As the
title suggests, it's about computer technologies that identify particular
human beings, as well as applications of those technologies to automated
tracking of highway traffic.  Here are the contents:

  Roger Clarke
    "Human Identification in Information Systems:
     Management Challenges and Public Policy Issues"

  Simon Davies
    "Touching Big Brother:
     How Biometric Technology Will Fuse Flesh and Machine"

  Marcus Wigan
    "The Influence of Public Acceptance on the Realisability of
     the Potential Benefits of Intelligent Vehicle-Highway Systems"

  Philip E. Agre and Christine A. Harbs
    "Social Choice About Privacy:
     Intelligent Vehicle-Highway Systems in the United States"

Full details on the issue, including abstracts for the papers, are available
on the web at:

Or through e-mail by sending a message that looks like this:

  Subject: archive send identification

Phil Agre, UCSD

Automatic file downloads in Seyon

Wed, 1 Feb 95 11:20:44 MST
I've recently started using the Seyon terminal program to dial in to my
university account from my home Linux system, and have discovered an
interesting risk that is found in Seyon, and perhaps other terminal

One thing I use Seyon for is uploading and downloading files using the
Zmodem protocol. To down load a file, you simply enter "sz filename" on the
host machine, and like magic, the file is downloaded. That is the risk.
Apparently, the sz program used to download files sends some special
character sequence that Seyon is set up to recognize, and then automatically
start the download. While this makes downloading nice and easy, it is
entirely possible that this sequence could take place without the user
noticing what was happening - there are no confirmations from the user
required for the download to take place.

It is not hard to imagine someone building a virus based on sending the
Zmodem startup sequence, and then simply downloading a file to the remote
system. I would imagine this could be even embedded into a regular text
posting. Thus a naive or tired or busy user could have some unknown file
downloaded to their system simply by reading some posting.

I imagine you can configure Seyon to avoid this behavior, but it is
apparently the default mode -- and one that is likely to be used by bunches
of people.  It is likely that other downloading protocols and terminal
emulation programs allow similar actions.  I think it is important to
recognize the risk in this, and at the least, any program that allows
automatic downloading should by default require the user to confirm that it
is OK to proceed. Power users can turn off the confirmation. New and casual
users would have some protection from unintentional downloads.

Bruce E. Wampler, Ph.D.     (
Adjunct Professor, Department of Computer Science, University of New Mexico

Announcement of new mailing list on ethical issues

Bashir Jiwani <>
Mon, 30 Jan 1995 18:32:42 -0800 (PST)
Hello.  My name is Bashir Jiwani and I am a graduate student in
philosophy at the University of British Columbia in Vancouver, Canada.  I
began looking into ethical issues of information technology for a
course I was taking this past semester.  I have developed an interest in
these issues and have decided to pursue this interest further.
To this end I am pleased to announce that with the help and support of the
UBC Centre for Applied Ethics a new mailing list that is intended for
discussion of topics in this area has been created.

This list is to be different from existing lists in this area in
several important respects.

Firstly, the list is to be moderated.  That is, all submissions to the list
will not automatically be posted to the list members.  Rather, they will
first arrive at the moderator's mailbox.  The moderator will then put
together the various submissions, screening for length and administrative
content, and then send them out to the list subscribers.

Secondly, and perhaps most importantly, there will be an established agenda
of topics that will serve to guide discussion on the list.  Rather than just
waiting around for something to happen to get people talking, I have put
together a list of topics that the discussion will progress through.  For
each topic I have tried to gather a few relevant articles as background
reading and have placed them at the list's WWW site.  As well I have
prepared some basic notes for each topic that fleshes out some of the issues
that are thought to be of concern.  In this way I have availed myself as the
presenter of these topics.  I have prepared so far presentations in three
topic areas.  My hope is that the role of presenter will be shared with the
members of the group who are interested in specific issues in information
technology ethics and who are willing to put together a small package of
background materials for the group's benefit.  So as we get to the last of
the topics I have set out, I am hoping someone else will have a specific
area of interest and will present this area to the list by sketching some of
the arguments at issue and by locating various articles that will give
participants some background information.

The third most significant difference is the WWW site that the list is
associated with.  The web site is to serve various functions.  It is to make
available the presenter's background materials either by providing links to
copies which may be located here or at other sites.  The web pages are also
intended to archive list discussions.  As well, any links that members might
feel may be useful can also be set up on these pages through the
administrative moderator.  As I have mentioned, I will be both
administrative moderator and topic presenter for the duration of the first
three discussion topics after which it is my hope that other members will
take on the role of topic presenter and I will refine myself to
administrative duties.

I believe that the list will be attractive to all users of information
technology.  The participation of philosophers as well as business
professionals is especially encouraged.

Due to the guided nature of the discussion, the list will officially open as
soon as a critical mass of members have signed up.  This mass has been set
at 40.  So as soon as forty people are subscribed to the list, the first set
of moderator's discussion notes will be mailed to all members.

To subscribe to the list, send the one-word message "subscribe" in the body
of an e-mail message to "".  For a more
detailed description of the list or to access the articles and moderator's
notes on the various topics or just to surf some interesting waves, visit
the web site at url:

Feedback on or about the list can be sent via the web pages or to the
moderator directly at

Bashir Jiwani  Vancouver, BC

CFP: 3rd International Workshop on Feature Interactions

Nancy Griffeth <>
Wed, 1 Feb 1995 15:43:57 -0500
               Call for Participation
Third International Workshop on Feature Interactions
         in Telecommunications Software Systems
                   Kyoto, Japan
                October 11-13, 1995


     This workshop is the third in a series, whose mission is to encourage
researchers from a variety of computer science specialties (software
engineering, enterprise modeling, protocol engineering, distributed
artificial intelligence, formal techniques, software testing, and
distributed systems, among others) to apply their techniques to the feature
interaction problem that arises in building telecommunications software
systems (see the back page for a description of the problem).  We welcome
papers on avoiding, detecting, and/or resolving feature interactions using
either analytical or structural approaches.  Submissions are encouraged in
(but are not limited to) the following topic areas:

   -    Classification of feature interactions.

   -    Modeling,  reasoning,  and  testing  techniques  for
        detecting feature interactions.

   -    Software platforms and architecture designs  to  aid
        in avoiding, detecting, and resolving feature interactions.

   -    Tools  and  methodologies  for  promoting   software
        compatibility and extensibility.

   -    Mechanisms   for   managing   feature   interactions
        throughout the service life-cyle.

   -    Management of feature interactions in PCS, ISDN, and
        Broadband services, as well as IN services.

   -    Management of feature interactions in various of the
        operations   support   functions   such  as  Service
        Negotiation, Service Management, and Service Assurance.

   -    Feature Interactions and their potential  impact  on
        system Security and Safety.

   -    Environments  and  automated   tools   for   related
        problems in other software systems.

   -    Management of Feature Interactions in various  other
        enterprises, such as banking, medicine, etc.


     We hope to promote a dialogue among researchers in various related
areas, as well as the designers and builders of telecommunications software.
To this end, the workshop will have sessions for paper presentations,
including relatively long discussion periods.  Panel discussions and tool
demonstrations are also planned. The first day of the workshop, October 11,
is devoted to tutorials and discussions on areas related to feature


     Workshop attendance will be limited to 100 people.  Attendance will be
by invitation only. Prospective attendees are asked to submit either a paper
(maximum 5000 words) or a single page description of their interests and how
they relate to the workshop.  Proposals for tutorials and discussions are
also requested (maximum 3000 words). About 16-20 of the attendees will be
asked to present talks; a small number of tutorials and/or discussions will
also be selected.  We will strive for an equal mix of theoretical results
and practical experiences. Papers will be published in a conference


     Please send five copies of your full original paper or interest
description to:

     Kong Eng Cheng
     Department of Computer Science
     Royal Melbourne Institute of Technology
     GPO Box 2476V
     Melbourne, Victoria
     AUSTRALIA 3001

     Tel: +61 3 660 3266
     FAX: +61 3 662 1617

Important dates are:

     February 28, 1995: Submission of contributions.
     May 15, 1995: Notification of acceptance.
     June 26, 1995: Submission of camera-ready versions.

Workshop Co-chairpersons

     Tadashi Ohta (ATR, Japan)
     Nancy Griffeth (Bellcore, USA)

Program Committee

     Kong Eng Cheng  (Royal Melbourne Institute of
                      Technology, Australia)
     E. Jane Cameron (Bellcore, USA)

Jan Bergstra         (CWI and University of Amsterdam,
                      The Netherlands)
Ralph Blumenthal     (Bellcore, USA)
Rolv Braek           (SINTEF DELAB, Norway)
Bernie Cohen         (City University of London, UK)
Robert France        (Florida Atlantic University, USA)
Haruo Hasegawa       (OKI, Japan)
Dieter Hogrefe       (University of Bern, Switzerland)
Richard Kemmerer     (UCSB, USA)
Victor Lesser        (University of Massachusetts, USA)
Yow-Jian Lin         (Bellcore, USA)
Luigi Logrippo       (University of Ottawa, Canada)
Jan van der Meer     (Ericsson, The Netherlands)
Robert Milne         (BNR, UK)
Leo Motus            (Tallinn Technical University, Estonia)
Jacques Muller       (CNET, France)
Jan-Olof Nordenstam  (ELLEMTEL, Sweden)
Yoshihiro Niitsu     (NTT, Japan)
Ben Potter           (University of Hertfordshire, UK)
Henrikas Pranevicius (Kaunas University of Technology,
Martin Sadler        (HP, UK)
Jean-Bernard Stefani (CNET, France)
Greg Utas            (BNR, USA)
Jyri Vain            (Institute of Cybernetics, Estonia)
Hugo Velthuijsen     (PTT Research, The Netherlands)
Yasushi Wakahara     (KDD R&D Laboratories, Japan)
Ron Wojcik           (BellSouth, USA)
Pamela Zave          (AT&T Bell Laboratories, USA)

Workshop Statement

     The feature interaction problem is a major obstacle to the rapid
deployment of new telephone services. Some feature communications system.
Telecommunications software is huge, real-time, and distributed; adding new
features to a telecommunication system, like adding new functionalities to
any large software system, can be very difficult.  Each new feature may
interact with many existing features, causing customer annoyance or total
system breakdown.  Traditionally, interactions were detected and resolved on
a feature by feature basis by experts who are knowledgeable on all existing
features.  As the number of features grows to satisfy diverse needs of
customers, managing feature interactions in a single administrative domain
is approaching incomprehensible complexity.  In a future marketplace where
features deployed in the network may be developed by different operating
companies and their associated vendors, the traditional approach is no
longer feasible.  How to detect, resolve, or even prevent the occurrence of
feature interactions in an open network is now an important research issue.

The feature interaction problem is not unique to telecommunications
software; similar problems are encountered in any long-lived software system
that requires frequent changes and additions to its functionality.
Techniques in many related areas appear to be applicable to the management
of feature interactions.  Software methodologies for extensibility and
compatibility, for example, could be useful for providing a structured
design that can prevent many feature interactions from occurring.  Features
are typically design to suit the purposes of a user or business, hence
Enterprise modeling will play a role in the identification of certain
classes of interaction, in particular the solution of an interaction in one
enterprise may not be desired by another.  Formal specification,
verification, and testing techniques, being widely used in protocol
engineering and software engineering, contribute to the detection of
interactions.  Several causes of the problem, such as aliasing, timing, and
the distribution of software components, are similar to issues in
distributed systems.  Cooperative problem solving, a promising approach for
resolving interactions at run time, resembles distributed planning and
resolution of conflicting subgoals among multiple agents in the area of
distributed artificial intelligence.  This workshop aims to provide an
opportunity for participants to share ideas and experiences in their
respective fields, and to apply their expertise to the feature interaction

Workshop Announcement

     3nd International Workshop on Feature Interactions in
Telecommunications Software Systems, October 11-13, Kyoto, Japan, Sponsors:
IEEE Communications Society. In cooperation with ACM SIGCOMM and ATR, Japan.
Contact Tadashi Ohta, ATR, 2-2, Hikari-dai, Seika-cho, Soraku-gun, Kyoto,
619-02, Japan, Tel: +81 7749 5 1230, Fax: +81 7749 5 1208, e-mail:

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