The RISKS Digest
Volume 7 Issue 77

Monday, 14th November 1988

Forum on Risks to the Public in Computers and Related Systems

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

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o UNIX InSecurity (beyond the Virus-Worm)
Klaus Brunnstein
o Unauthorized Access
Dennis G. Rears
o re: NY Computer Laws and the Internet Worm
Forrest Colliver
o Re: NSA attempts to restrict virus information
Steven Bellovin
o Risks of unchecked input in C programs
Bill Stewart
Bob Frankston
o Worms & Ethics
Don Wegeng
o One count, or multiple counts?
Richard Wiggins
o The RISKS of jargon
Dave Horsfall
o University of Surrey Hacker
Brian Randell
o Re: UK vehicle-identification systems
Steven C. Den Beste
Franklin Davis
o Info on RISKS (comp.risks)

UNIX InSecurity (beyond the Virus-Worm)

Klaus Brunnstein <>
11 Nov 88 15:27 GMT+0100
Sitting far away from the `center of epidemy' (and not using UNIX), I
observe with great interest the analysis of the `Virus Worm'. In FRG
newsmedia, the New York Times article produced public uproar, with several
newspapers and the magazine `Der SPIEGEL' (in its November 7 edition)
speculating, that something similar might happen to the computers of banks,
tax authorities and state agencies. Moreover, the damage is reported to have
affected `more than 6.000 large computers connected to ARPANET', and
additionally, Joseph Weizenbaum is cited saying that this virus may also
affect the really sensitive military US-installations.

Evidently, a large portion of the newsproducers is infected by the `Virus of
Disinformation'. First lesson to be learned:  the insecurity of relevant
operating systems, well-known to experts since long time, must be
disseminated from specialists to the computer profession. If even Edp people
are not conscious of the risks imbedded in today's operating systems, we
cannot hope for solid public presentation of such events.

In my personal fight against usage of UNIX in processing sensitive data
(such as in medical, economical and public applications), I usually find my
audience deeply surprised when citing F.T.Grampp and R.H.Morris, who in
their AT&T Bell Lab Technical Journal (October 1984) article about UNIX
Operating System Security wrote, after analysing the merits of `open
systems' such as UNIX:

   `Such open systems cannot ever be made secure in any strong
    sense; that is, they are unfit for applications involving
    classified government information, corporate accounting,
    records relating to individual provacy, and the like...'

When I chaired, at the German Unix User Group annual conference in Hannover,
September 1988, the session devoted to UNIX SECURITY, one speaker analysed
that a Secure UNIX would hardly get a higher Orange Book classification than
C2 or B1 because otherwise the restrictions and changes would produce
something very different. A `security shell', as now planned by X/OPEN, is a
contradiction in itself, because effective security must be implemented in
the kernel. Moreover, real security deficiencies are even worse, as `most
UNIX systems are far less secure than they can and should be', as
Grampp/Morris wrote in 1984: while the SENDMAIL/DEBUG allows for worm
applications such as network and remote system monitoring, fault analysis
and maintenance, it may be the basis of even really harmful crimoid
applications, such as Trojan Horses, Viruses or automated espionage

(While Gould hopes to get DoD class B1, sometime early in 1989, for its new
Secure UNIX concept, someone told me that IBM's AIX has been rated B1; can
anybody inform me, whether this is true?)

Despite of such insight (even of their employees), several manufacturers try
hard to sell UNIX systems to banks, medical institutions and state agencies,
in conscious contradiction to Grampp/Morris insight. While specially
protected `production systems' are neither available nor developped, the
installation, first isolated but later integrated into complex systems, of
such inherently insecure systems will inevitably produce a `big bang' in
some not to distant future: the criminal potential is deeply embedded in the
systems, more than in their abuse.

While the Virus-Worm did evidently produce only limited damage (esp.
`eating' time and intelligence during a 16-hour nightshift, and further
distracting activities in follow-up discussions, but at the same time
teaching some valuable lessons), the consequence of the UNIX euphoria may
damage enterprises and economies. To me as an educated physicist, parallels
show up to the discussions of the risks overseen by the community of nuclear
physicist. In such a sense, I slightly revise Peter Neumann's analogy to the
Three-Mile-Island and Chernobyl accidents: the advent of the Virus-Worm may
be comparable to a mini Three-Mile Island accident (with large threat though
limited damage), but the `Chernobyl of Computing' is being programmed in
economic applications if ill-advised customers follow the computer industry
into insecure UNIX-land.

Klaus Brunnstein     University of Hamburg     FRG

Unauthorized Access

"Dennis G. Rears (FSAC)" <drears@ARDEC.ARPA>
Sat, 12 Nov 88 13:37:18 EST
Dave Bozak writes:

>    Clearly the design and release of a worm is a violation of
>section 156.10.  The worm was released was intended to gain access to
>machines without authorization and was designed to gain access to
>material (host lists) for propagation of the worm.
>    Now maybe I am missing something here, not being a
>would learned colleagues please clarify the legal issues involved
>in this particular case?

   The key is "unauthorized access".  The sendmail process from the target
machine allowed him to access it.  He did not access that process without
authorization; he just gave it something it didn't want.  Sendmail accepted it.
Because of that, he did not brake that law.
  The main problem with making worms/viruses illegal is drafting the laws.
What is authorized access?  If a friend of mine on Computer "A" gives me his
password; does that in itself give me authorized access?  Since I am on the
milnet I can fing, ftp anonymously, send mail to lots of computers.  All of
these actions I have implied authorization.  When dealing with networks the
laws have to prohibit actions once access is made not prohibit access.

Dennis G. Rears: Computer Scientist, 1LT USAR & Civil Servant
AT&T:   201-724-6639      SMCAR-FSS-E, Bldg 94, Picatinny Ars, NJ 07806

re: NY Computer Laws and the Internet Worm

Forrest Colliver <>
Sat, 12 Nov 88 16:55:11 EST
With respect to the apparently "obvious" breaking of laws in the Internet worm
case, bear in mind that the FBI only has jurisdiction in cases which involve
federal crimes, or in cases where a suspect crosses state lines in conjunction
with unlawful activities which would otherwise fall into state or local
jurisdiction.  Thus, breaking of NY state laws would not automatically allow
the FBI to begin an investigation.  It does seem that the progress of the worm
across state boundaries would allow the FBI to assume federal jurisdiction, but
I suspect that without precedents to fall back on, the legal profession is
proceeding with caution!

F.C., The MITRE Corp., Washington, D.C.

Re: NSA attempts to restrict virus information <Steven Bellovin>
Sat, 12 Nov 88 22:49:54 EST
The situation is rather worse than the Times and AP have reported.  The NSA is
exerting a great deal of pressure to have disassembler output from the virus
(to say nothing of C source) available to as few people as possible.  When they
learn of a copy in a repository (say, available for anonymous FTP), they ask
their contact — perhaps an administrator, perhaps a name they happen to know
at that school to remove it.  If that person hesitates, or expresses a wish to
contact the person who made it available, they immediately contact the
president of the university, who calls the dean, who calls, etc.  As best I can
tell, they have no legal authority to order the removal.  But they are not
hesitating to bring as much pressure to bear as they can, to try to scare folks
into complying.
                                    --Steve Bellovin

Risks of unchecked input in C programs

Sun, 13 Nov 88 22:31:43 EST
In RISKS 7.74 Geoff Collyer wrote about the finger-daemon hole caused by gets's
lack of checking on the size of the input, and called for gets's eradication
("A bug waiting to happen").  While the ancestry of gets is certainly dubious,
scanf() suffers from the same problem as commonly used (do *you* always use
%50s instead of %s?  "man scanf" doesn't).

I've always been dissatisfied with the printf/scanf family - field widths are
hard-coded in the format strings, with no way to parameterize them except
building format strings on the fly, and there's no nice way to read/print
arrays except character strings.  It would be nice to say
    int i, data[NITEMS]; char *string;
    string = emalloc(whatever);
    scanf("%nd %ns", NITEMS, data, whatever-1, string);
and know it would read the correct amount of data into each array,
and to write    printf("%n10f\n", 4, data);
instead of  printf("%10f%10f%10f%10f\n", data[0], data[1].....);

Bill Stewart!wcs       AT&T Bell Labs, Holmdel NJ

Re: Risks of unchecked input in C programs (RISKS-7.74)

bobf@lotus.UUCP <Bob Frankston>
Mon Nov 14 10:05:25 1988
The "little care" necessary to use the string functions safely amounts to
reimplementing them which renders them pointless but they are very dangerous in
that the "not so careful" are so numerous.

Worms & Ethics

Don Wegeng <Wegeng.Henr@Xerox.COM>
14 Nov 88 16:52:23 EST (Monday)
In reference to the recent Internet Worm incident, I was going through my
library last night and found that CACM vol. 25, no. 3 (March 1982) contains
two relevant articles. The first is the well known Worm paper by Shoch &
Hupp, immediately followed by "A Self-Assessment Procedure Dealing with
Ethics in Computing," edited by Eric A. Weiss. In light of recent history
this is an interesting coincidence.

Perhaps we should teach Computer Science students to read the entire journal
issue when they're reading papers on a particular topic. :-(

One count, or multiple counts?

Mon, 14 Nov 88 09:51:32 EST
The Federal law that's been mentioned as the likely tool for prosecution of
Morris Jr makes the first transgression a misdemeanor and subsequent ones a

The question is, did Morris invade hundreds of computers, or did he invade one

As they say, "the network is the system."  And it appears that he fired only
one salvo — albeit with 3 warheads.

-- Rich Wiggins,    Systems Programmer,    Michigan State University

The RISKS of jargon

Dave Horsfall <>
Fri, 11 Nov 88 14:17:00 est
One of the RISKS in the use of computers is that it engenders a jargon that is
at odds with community acceptance e.g. "ram", "mouse" etc.

Here is an example of such a RISK that is the other way around, taken (without
permission) from the "Backbytes" page in "Computing Australia", Nov 7, 1988:

``Well, it sounded like an opening.

  Some chipocentric people have difficulty accepting that computers
  aren't the centre of the universe (Whoops!  Is IBM reading this?).  Or
  perhaps it's just that the jargon of the public service is enough to
  throw even computer aficionados (masters of their own gobbledegook).
  Whatever, DDP's state-of-the-art Canberra rep thought he had the
  makings of a sale recently.

  Spotting a Dept.  of Arts, Sport, Environment, Tourism and Territories
  [ yes, Australian bureaucracies are like that!  ] advertisement
  inviting tenders for the "supply and installation of a restricted
  keying system", Richard Presser's white-haired boy thought: "We've got
  just the thing, our Rode/PC!"

  This esoteric device delivers dedicated data entry system performance,
  which is to say, it's a keying system.  At least in computing argot.
  That very day he wrote off requesting more details and, of course,
  tender forms.  To his great astonishment, it turned out what the
  department actually wanted was 108 locks for lockers and and other
  equipment at the Fraser (ACT) Primary School.

-- Dave

University of Surrey Hacker

Brian Randell <>
Thu, 10 Nov 88 19:14:00 GMT
There has been a lot of recent publicity in the U.K. about the arrest of a
hacker at the University of Surrey. There were stories about his investigation
by Scotland Yard's Serious Crimes Squad and by the U.S. Secret Service, and
much dicussion about the inadequacy of the law relating to network hacking - as
far as I know he has only been charged with offences relating his unathorised
(physical) entry to the University buildings.

An article in today's Guardian newspaper that is based on an interview with the
individual, one Edward Austin Singh, reveals that his techniques were simply
based on a program which tricked users into unsuspectingly revealing their
passwords. "I wrote a program that utilised a flaw that allowed me to call into
the dial-up node.  You always do it by phoning, never by the network.  The
dial-up node has to have an address as well, so we were calling the address
itself. I called the dial-up node via the network and did it repeatedly until
it connected.  That happened every 30 seconds.  It allowed me to connect the
dial-up node at the same time as a legitimate user at random.  I would then
emulate the system."

He used to run this program at night, and specialised in breaking into Prime
computer systems: "I picked up about 40 passwords and IDs an hour. We were
picking up military stuff like that, as well as commercial and academic", he
claims. This enabled him to get information from more than 250 systems
world-wide, and (he claims) in concert with an underground hackers network, to
"access virtually every single computer system which was networked in the US -
thousands and thousands of them, many of them US Arms manufacturers".

The article states that "Prime Computers have so far declined to comment on his
approach to them or his alleged penetration of their computer systems, until
the American Secret Service completes its enquiries."

Brian Randell

Re: UK vehicle-identification systems

Mon, 14 Nov 88 09:16:05 -0500
I find Chaz's description of the new system in Britain for toll-roads very
interesting, to say the least. I have some interesting questions:

1. As I understood it, what we have is a radio handshake between each car and
fixed tranceivers at the entrance and exit from the toll-road, presumably
connected to a computer billing system which mails you a bill each month. What
if you move and don't tell the computer your new address?

2. The idea is that with this mechanism it won't be necessary for the car to
stop or slow down, as we must do here on the Masspike with traditional toll
booths. More interesting is that it will presumably work in heavy traffic at
high speeds. Not only won't it be necessary for the car to slow down, it can't
do so without causing an accident. So if for any reason the handshake fails,
the system has no recourse. Which leads to the interesting speculations:

3. The handshake happens at a certain radio frequency. What happens if the car
happens to carry a low-power RF noise generater at just that frequency?

4. What happens if someone figures out how to get into their car's tranceiver
and change the signature? It doesn't even have to be a valid one because there
isn't any way for the highway to stop the car or log what it is.

5. What happens to cars which have crossed the Channel from France? Here in
Massachusetts we have people who register their cars in New Hampshire to avoid
the property tax (illegal, by the way); will Brits be registering their cars in
Brittany to avoid the highway tolls?

6. Everything screws up. I can see the following scenario: John drives the A13
(or some other typical highway designation - I made this one up based on, sigh,
Monty Python) to work every day. On Friday he gets on it (handshake succeeds)
and drives home and gets off it (handshake fails for some odd reason - a nearby
lightning strike just during the handshake?); Monday morning he gets back on it
to go to work (another lightning strike louses up the handshake - isn't the
weather *terrible* this time of year?) and gets off it near his job (handshake
   What does the computer see? It sees John getting on Friday evening and not
getting off until Monday morning. John sure must have driven a lot of miles
that weekend - let's bill him big.

7. Just what WILL the computer do with a partial transaction - get on but don't
get off, or vice versa? I can think of many ways this could happen.

8. Since there will be some cars on the highway without tranceivers (French
etc.) then the system can't scream when it sees one. What is to keep someone
from driving an ice-pick through their tranceiver with a hammer, or much more
simply, pulling its fuse or clipping its power lead? Will the British meter
maids start carrying little tranceiver-testers around checking every parked car
to see if its tranceiver will handshake? The mind boggles. (I think that
pulling the fuse is the best answer - that way you can plug it in again just
before the yearly equipment check.)

Frankly, it sounds like the greatest target for hackers since the ARPAnet!

Steven C. Den Beste,   BBN Communications Corp., Cambridge MA    harvard!!denbeste(UUCP)

UK vehicle-identification systems

Mon, 14 Nov 88 14:52:19 EST
In his 10 Nov 88 RISKS contribution, Douglas Jones discusses optical and
microwave barcode scanner devices for collecting tolls from cars.  He
  The risk of such sensors as police devices depends to a great extent on how
  easy it is to instrument locations in the roadway without the driver being
  aware of it.

Why not make use of such a system voluntary?  If I had a choice between
lining up to drop coins in a gate vs. driving through a barcode-reading
gate, I'd choose the latter, assuming it meant I wouldn't have to come to a
stop.  But anyone who prefers anonymity could always use the regular toll
gate (where presumably no one is writing down license plate numbers) and
not install the barcode on their vehicle.  The principle seems to me to be
that if you are potentially diminishing someone's privacy, they should have
a choice about it, and the costs and benefits should be made clear.

--Franklin Davis    Thinking Machines Corporation

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