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RISKS-LIST: RISKS-FORUM Digest Friday 27 October 1989 Volume 9 : Issue 36

FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

Contents: Bug in Intel 486 chip (PGN) UK Banking Error (Brian Randell) The Presentation of Risky Information (Joshua Levy) Hardware failure mimics hackers (Pat White, Andy Goldstein) Worms in a data stream (Rick Simkin) CERT Advisory on Sun RCP (J. Paul Holbrook) Warning About CERT Warnings (anonymous) Licensed users exceeded (Tim Steele) A lesson involving 'CRACKERS' (APPLE II) (Olivier Crepin-Leblond)

The RISKS Forum is moderated. Contributions should be relevant, sound, in good taste, objective, coherent, concise, and nonrepetitious. Diversity is welcome. CONTRIBUTIONS to RISKS@CSL.SRI.COM, with relevant, substantive "Subject:" line (otherwise they may be ignored). REQUESTS to RISKS-Request@CSL.SRI.COM. TO FTP VOL i ISSUE j: ftp CRVAX.sri.com<CR>login anonymous<CR>AnyNonNullPW<CR> cd sys:[risks]<CR>get risks-i.j . Vol summaries now in risks-i.0 (j=0)

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Date: Fri, 27 Oct 1989 10:41:03 PDT From: "Peter G. Neumann" <neumann@csl.sri.com> Subject: Bug in Intel 486 chip

This morning's San Francisco Chronicle notes that there is a flaw in the trigonometric functions in the new 486 chip. It was discovered by Compaq in testing its new system, expected to be announced on 6 November. New chips without the flaw will begin to appear next week, with volume production a few weeks away. This may delay some of the applications that are in the works.

The chip contains 1.2 million transistor equivalents, and at 12 to 15 MIPS is three times faster than the 386 chip. 200 companies are reportedly actively designing new computers using the chip.

[Which chippies could talk about a better MOS TRAP with everyone making a beaten path to their door?]

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Date: Fri, 27 Oct 89 16:54:02 BST From: Brian Randell <Brian.Randell@newcastle.ac.uk> Subject: UK Banking Error

There has been a follow-up article in Computer Weekly (Oct 26, 1989, p.9) to the story about the software error which caused #(pounds)2 billion in duplicate payments, which I posted to RISKS (UK Banking Error, RISKS 9.33) last week. The new article, though quite lengthy, doesn't add much detail. However it does reveal that the bank concerned was Citibank, that 95% of the #2bn payments were reversed within the same day, that delays only occurred where Citibank was "acting through intermediaries or other branches", and that all the money was returned within three days.

The nicest bit in the new article is where it indicates that the story was originally broken in a speech by Jim Reeves, technical manager of the Clearing House Payment Systems (Chaps) to a gathering of bankers and other financial industry delegates at the Compsec computer security conference:

"Reeves struck observers as the most unlikely bean-spiller in the financial industry. His voice was so unexpressive that his Compsec speech left one immaculately dressed banker in the audience slumped across two seats, snoring loudly.

The enormity of the #2bn error was lost on his audience. Yet Reeves was saying, in effect, that in a matter of minutes a systems or operator error could cost a bank more than its annual profits."

And the article ends:

"Citibank insisted that there had been no financial loss to the bank or any third party as a result of the error. But this comment begs many questions which Citibank would not answer. What about the lost interest on the #2bn? Even a day's lost interest would amount to more than #500,000. ... To most people the idea that systems could be so vulnerable as to allow a criminal, perhaps organised criminals, to divert electronically hundreds of millions into false accounts would be inconceivable - just as incredible as the notion that a bank could pay out #2bn by mistake."

Brian Randell, Computing Laboratory, University of Newcastle upon Tyne, UK

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Date: Thu, 26 Oct 89 16:44:31 PDT From: joshua@Atherton.COM (Flame Bait) Subject: The Presentation of Risky Information

Background: I have written a paper, "A Comparison of Commercial RPC Protocols" (RPC stands for Remote Procedure Call, and it is a simple way of writing distributed applications). This paper contained two sections: one comparing the speed of various RPC products, another comparing their reliability. This paper has been read by dozens (hundreds?) of people, and I have gotten a lot of feed back about it.

Problem: The problem is that everyone ignores the reliability section of the paper. People are constantly discussing the relative speeds of the RPC systems, but they ignore the differing reliability measures.

I am in the process of writing the second version of this paper, and I want people to pay more attention to RPC reliability, but since I do not know why they ignored reliability in the first paper, I do not know what to change in the second paper.

Discussion: In the first version of the paper the speed section came first and was longer than the reliability section (3 pages vs. 1 page). For the second version, I plan to put the reliability section first, and try to run more reliability tests. Unfortunately reliability is, in many ways, simpler than speed, so I doubt the reliability section will ever be as long as the speed section.

A second possible problem is that my wording was to neutral or too clinical, and that I should replace it with stronger or more emotional language.

I have a bad feeling that the reaction I am seeing is just a reflection of the fact that programmers and programming companies care much more about speed than reliability. I'm worried that no matter how I present the information, the reliability numbers will be ignored.

If you have any thoughts (answers or just comments) please email them to me, even if you send them to RISKS. (I do not seem to get every RISKS issue.) I will summarize responses sent to me. Tell me if you do not want your response summarized, or if you want to be anonymous. Thanks.

Availability: The paper in question, comparing RPCs, is available by sending email to archive-server@joshua.atherton.com. The body of the message should contain the lines "send other comprpc.shar" or "send other comprpc.txt". The first line will give you the paper in troff's me macros, the second in plaintext.

Joshua Levy joshua@atherton.com home: (415) 968-3718 {decwrl|sun|hpda}!athertn!joshua work: (408) 734-9822

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Date: Fri, 27 Oct 89 12:38:37 -0500 From: ain@sage.cc.purdue.edu Subject: Re: Hardware failure mimics hackers (Rob Wright, RISKS-9.35)

>Sure enough, when the FPA was replaced in our Geophysics machine the problems >vanished. Apparently the FPA is used for password encryption. No one has >satisfactorily explained the 'licensed users exceeded' phenomenon.

If your FPA is like the one on our dual 780's, then it is also used to speed up integer math -- therefore, inode calculations and the like can be affected. Since file system damage was reported, this probably was the case. So, the 'licensed users exceeded' might be caused by the system looking at the wrong disk sectors.

>As to the failure mode of this subsystem, one presumes that those computing at >the time of the failure would have some wrong answers, but further users were >spared this worry by not being able to access the system.

Yup, they do get wrong answers... and sometimes even notice it (which is another computer "risk" -- people assuming that computers *never* make math mistakes).

Pat White

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Date: Wed, 25 Oct 89 15:08:02 PDT From: goldstein%star.DEC@src.dec.com (Andy Goldstein) Subject: RE: Hardware failure mimics hackers (Rob Wright)

A couple of points regarding the notes from Rob Wright and Tom Ivers regarding wholesale password failures and multi-user licensing problems caused by a faulty floating point accelerator:

(1) The FPA implements integer multiply as well as the floating point operations, since a fast integer multiply helps array references often associated with floating-point intensive applications.

(2) The Purdy algorithm [CACM, August 1974] VMS uses for one-way encryption of passwords makes extensive use of integer multiply operations.

(3) The multi-user license validation algorithm used in VMS V4.* also uses the Purdy algorithm in checking its license database.

Thus the bad FPA causes both user passwords and the multi-user licensing to fail. (Actually, a bad FPA can cause all sorts of things to fail because of the multiply implementation. Just another unfortunate consequence of an operating system's assumption that the CPU works.) Andy Goldstein, VMS Development

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Date: Thu, 26 Oct 89 14:35:00 EDT From: simkin@zah.samsung.com (Rick Simkin) Subject: Worms in a data stream

In issue 9:35, Will Martin reported on an article which suggested that a data stream could somehow corrupt the workings of a computer system. He also expressed skepticism about this claim. From what I've heard recently, his skepticism is correct, as the claim itself is the product of confusion.

At a recent seminar hosted by the Greater Boston Chapter of the ACM, Pamela Kane and Andy Hopkins of Panda Software discussed this notion briefly. They cited a magazine article where someone had speculated that a spreadsheet overlay might contain malicious actions. Since spreadsheet files are commonly considered data, the Incautious Reader could jump to the conclusion that malicious data could take over a computer's operations.

Pamela Kane was quick to point out that a file which contained executable instructions--even if they were to be interpreted by another program, rather than run directly by the hardware--shouldn't rightly be considered a "data file."

Rick Simkin, Samsung Software America, Inc., 1 Corporate Drive, Andover MA 01810 Any opinions expressed are my own, not my employer's.

[Don't forget the old squirreled-character mail message problem, where the normal reading of the mail message could trip up on a control character or escape sequence and cause a nasty effect. Just because it is data does not mean that it cannot somehow get executed... PGN]

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Date: Thu, 26 Oct 89 21:26:06 EDT From: CERT Advisory <cert@cert.sei.cmu.edu> Subject: CERT Advisory on Sun RCP

CERT Advisory October 26, 1989 Sun RCP vulnerability

A problem has been discovered in the SunOS 4.0.x rcp. If exploited, this problem can allow users of other trusted machines to execute root-privilege commands on a Sun via rcp.

This affects only SunOS 4.0.x systems; 3.5 systems are not affected.

A Sun running 4.0.x rcp can be exploited by any other trusted host listed in /etc/hosts.equiv or /.rhosts. Note that the other machine exploiting this hole does not have to be running Unix; this vulnerability can be exploited by a PC running PC/NFS, for example.

This bug will be fixed by Sun in version 4.1 (Sun Bug number 1017314), but for now the following workaround is suggested by Sun:

Change the 'nobody' /etc/passwd file entry from

nobody:*:-2:-2::/: to nobody:*:32767:32767:Mismatched NFS ID's:/nonexistant:/nosuchshell

If you need further information about this problem, please contact CERT by electronic mail or phone.

J. Paul Holbrook, Computer Emergency Response Team (CERT) Carnegie Mellon University, Software Engineering Institute Internet: <cert@SEI.CMU.EDU> (412) 268-7090 (24 hour hotline)

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Date: Thu, 26 Oct 89 23:43:41 [x]DT From: [Anonymous] Subject: Warning About CERT Warnings

In RISKS 9.34, CERT once again passes along advice on checking for security holes. Once again CERT recommends use of the UNIX utility "sum". Forgive me for shouting, but THE UTILITIES ON A POTENTIALLY COMPROMISED SYSTEM SHOULD NOT BE USED TO EVALUATE THAT SYSTEM'S SECURITY. This is especially true when CERT publishes the output the utility should produce. Another possibility is that a compromised file might be constructed in such a way as to produce the same output as an uncompromised file, even when viewed with an uncompromised utility.

A poor security procedure is worse than no procedure, because the poor procedure may produce a false sense of security. It's better not to know the truth and remain paranoid, than to know a false truth and feel comfy.

Sometimes I wonder whether CERT has been penetrated by a hacker.

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Date: Thu, 26 Oct 89 09:51:39 BST From: Tim Steele <tjfs@tadtec.uucp> Subject: Licensed users exceeded

When I was using ULTRIX, we had the same problem after a system upgrade - the system would only allow 2 users to log in before reporting that the number of licenced users had been exceeded. Calling DEC confirmed this was the case, as they had just (in that release) installed a mechanism to check this. They promised they would ship us a tape to allow us to carry on using the system as before, but said it would take "several weeks".

I wasn't happy with this as we needed the system back online that morning (!) so I broke the protection system. Essentially it used a file in / (called /.license, I think) which contained 1K or so of "random" junk. This is the file you buy from DEC for a certain fee depending on how many users you want to enable on your system. The file gets opened by /etc/init and the number of licensed users read out and checked for every time a new login process is started. This number is also printed at boot time.

GOTCHA: The number printed is NOT the same as the number used in the check! For a "real" license shipped by DEC, these numbers will be the same. The idea is to stop crackers disassembling init and patching the obvious number printed at startup. The real number is stored in several places in a suitably tricky way. Even so, armed with a couple of genuine licence files, it's fairly easy to crack. I ended up with a 10-lines-of-C utility that would forge any licence you liked...

If init reckoned the license was not valid, it would default to the minimum, i.e. 2 users. I suspect the VMS mechanism is similar, and is defaulting to 2 users as the value returned from the (bad) FPA is not matching the proper encrypted value in the system license.

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Date: Thu, 26 OCT 89 18:43:52 GMT From: Olivier Crepin-Leblond <ZDEE699@elm.cc.kcl.ac.uk> Subject: A lesson involving 'CRACKERS' (APPLE II)

This message is being sent to both RISKS and VIRUS lists. Apologies to those who receive both digests.

I was well shocked in finding-out that there was actually a virus running on the Apple II family of computers ! Where could the LODE RUNNER virus have infected such a small machine, with no integrated hard disk, and the possibility of rebooting the machine quickly by using a simple sequence of control codes ? (open-apple-ctrl- reset ). In FRANCE, of course !

The Apple II did very well in France. It is very widely used over there. This success, like in the U.S.A., triggered a large market for pirated copies of programs.

I have been an Apple II owner since 1982. It is absolutely amazing how many copies of programs went around since that time. I guess that virtually every program for this type of computer was available as a pirated copy in France. This is because of the following:

1. There are laws about unlawful software copying, but they are very hardg problems in Toronto (Amit Parghi) NH State Republican Convention Computerized Voting Standard (Kurt Hyde) Ethics (Hugh Miller) Re: Teaching "Ethics" (Brint Cooper) Decompiled Source (Phil Karn) Re: Risks of unchecked input in C programs (Henry Spencer) Smart Roads (Robert Brooks) IFF & UK Toll Roads (Nigel Roberts) Re: "Electronic number plates" (Allan Pratt) Re: UK vehicle-identification systems (John Haller) RISKS 7.82 23 Nov 88 Troubles with automatic vote counting in Toronto (Mark then protected again, and sold to customers for a fraction of the price. The pirates were arrested and heavily fined (and given a prison sentence).

SOME SORT OF COMPETITION

There were many independent groups of pirates. The average age was 16-22 years old. All of them were experts at Apple II's Disk Operating System. The most "advanced" of these "crackers" were the CCB. CCB for "Clean Crack Band". From the number of programs that they have cracked, they seemed to spend their days and nights cracking games and software. Some French magazines and newspapers wrote articles and interviews with them. They even went on national French TV. Of course, they were in hiding; a bit like drug dealers, really. The quality of their "work" was unbelievable. The program was as good as new, only it had their name in the presentation page. Often, they added pretty graphics, and additional options in some cases. In fact, it looked as though they had completely re-written the program entirely. At the end of 1985, I think, they renamed themselves, the SHC, "Solex Hack Band". (A Solex used to be a cheap moped at the time) They hacked a few French Computers by using dial lines; they did one "Hacking" direct, on TV, showing the journalists how vulnerable computers were. Since that time, I don't know what happened to them.

OTHER GROUPS

There are a lot of other groups of pirates around France. The CCB were based in Paris (according to the press), and the two most famous members of this group called themselves: Aldo Reset, and Laurent Rueil. Other groups include:

- Johnny Diskette: this name was used by many anonymous pirates who had formed some kind of club in Paris, where they had competitions (!) on who would be the fastest to unprotect a disk. - BCG (Baby Crack Gang): funny name. They seemed to like Karateka games. - CES (Cracking Elite Software): They added features to games from time to time. - Chip Select and the Softman: These pirates went as far as including a digitised picture of themselves wearing dark glasses and saying: "I am Chip Select". A Certain Eric IRQ (Interrupt Request) was also part of this group. - Mister Z (Geneva): These were Swiss pirates, but for some reason, they were sending copies to French crackers, telling them to change the title page that they had made-up. It was some kind of competition of: "We can protect this program; can you unprotect it ?" - MAC (Marseilles Association of Crackers): group based in Marseilles. - P.Avenue Nice: and this one is in Nice...

These groups deprotect the software. Once deprotected, it can be copied very easily using a normal copy program. Most copying goes-on in large computer centres, where machines can be used free of charge. There is no supervision there, and no control on what goes-on. Somes places are popular just because it is such an easy way to get hold of any program for no charge (well... just the cost of a diskette). Since 1987, though, the shops are more careful since they could be held responsible for what happens on their machines.

HIDDEN INFO

If you use a track/sector disassembler, you can see the information on the tracks of the disk displayed as ASCII characters. Often crackers would converse between themselves in this way. Software is copied through a string of intermediaries, and the messages can therefore be passed this way. It is impossible to know if there is some hidden information on the disk if it is not analysed by using a track/sector disassembler. It is therefore very easy to hide other programs within the disk, whether they are games, or even viruses !

IN CONCLUSION

So in fact, considering the level of expertise that these crackers have, it would be very easy for them to hide a virus within a floppy disk, which would be triggered by the actual program. I am talking here about the APPLE II computer, but I am sure that other computers (including PC's) have their "expert" crackers, who no doubt, would be very happy to write viruses/worms/trojan horses/time bombs etc. Why do they do it ? My idea is that they do it for "fame", just to see other people talk about "their" virus. Any suggestions ?

Olivier Crepin-Leblond, Computer Systems & Electronics, Electrical & Electronic Eng., King's College London

Disclaimer: My own views. Any comments/flames/congratulations welcome !

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End of RISKS-FORUM Digest 9.36 ************************