RISKS-LIST: Risks-Forum Digest Monday 17 January 2005 Volume 23 : Issue 67 ACM FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS (comp.risks) Peter G. Neumann, moderator, chmn ACM Committee on Computers and Public Policy ***** See last item for further information, disclaimers, caveats, etc. ***** This issue is archived at <http://www.risks.org> as <http://catless.ncl.ac.uk/Risks/23.67.html> The current issue can be found at <http://www.csl.sri.com/users/risko/risks.txt> Contents: Loss of data from Huygens Probe (John Murrell) 130 most common bugs -- and counting (Peter Ludemann) Cellery worm plays games with victims (NewsScan) Hollywood Sign Security (Bruce Schneier) Problems with Chicago-area toll road transponders (jhhaynes) GPS used to arrest snowplow driver (David Tarabar) Re: A Comedy of Errors (Rex Black) Yet another route map software problem (Nick Brown) MapPoint explains Vikings? (Adam Shostack) Re: Risks of lenient parsing (Doug McIlroy, Walter Roberson, Roger Burton West, Jonathan Kamens, Russell Smiley, Sander Tekelenburg) Copyright and reverse engineering (Rob Slade) Re: High Tech Crimes Revealed" (Steven Branigan) Re: A Kafka day at the Los Angeles traffic ticket office (Paul Robinson) Abridged info on RISKS (comp.risks) ---------------------------------------------------------------------- Date: Sat, 15 Jan 2005 20:38:57 -0000 From: "John Murrell" <johnmurrell@private> Subject: Loss of data from Huygens Probe It appears that data was only received from one of the two semi-redundant communications channels from Huygens by the Cassini spacecraft. At this morning's press conference it appears that one of the two receivers on Cassini was not turned on due to a software error. This has not caused a major loss as most data was duplicated between channels - the only two losses are that 50% of the images are lost but most of these will overlap with images sent on the other channel. Also the 'Doppler Wind' experiment relied on the carrier signal from the channel that was not switched on however it is believed that this information can be reconstructed from the radio telescope observations that were tracking Huygens. ESA has set up a board of enquiry into why the receiver was not turned on. It is interesting to know why 'end to end' system tests did not find this. ------------------------------ Date: Sat, 15 Jan 2005 12:13:33 -0800 From: Peter Ludemann <p_ludemann@private> Subject: 130 most common bugs -- and counting Bruce Tognazzini has started collected well-known bugs at http://asktog.com/Bughouse/index.html ... many of these have shown up before in Risks, such as "Harassing Confirmations & Missing Confirmations" and "'Smart' functions that aren't smart". Readers might also enjoy (if that's the right word) Tognazzini's article on Security D'ohlts: http://asktog.com/columns/058SecurityD'ohlts.html and an older article on how inconvenience and security are confused: http://asktog.com/columns/051AirSecurity.html ------------------------------ Date: Fri, 14 Jan 2005 06:19:58 -0700 From: "NewsScan" <newsscan@private> Subject: Cellery worm plays games with victims Users are being warned about the Cellery worm -- a Windows virus that piggybacks on the hugely popular Tetris game. Rather than spreading itself via e-mail, Cellery installs a playable version of Tetris on the user's machine. When the game starts up, the worm seeks out other computers it can infect on the same network. The virus does no damage, but could result in clogged traffic on heavily infected networks. "If your company has a culture of allowing games to be played in the office, your staff may believe this is simply a new game that has been installed -- rather than something that should cause concern," says a spokesman for computer security firm Sophos. [BBC News, 13 Jan 2005; NewsScan Daily, 14 Jan 2005] http://news.bbc.co.uk/1/hi/technology/4170903.stm ------------------------------ Date: Sat, 15 Jan 2005 02:50:05 -0600 From: Bruce Schneier <schneier@private> Subject: Hollywood Sign Security >From Bruce's CRYPTO-GRAM, January 15, 2005 http://www.schneier.com/blog/archives/2004/12/physical_access.html In Los Angeles, the "HOLLYWOOD" sign is protected by a fence and a locked gate. Because several different agencies need access to the sign for various purposes, the chain locking the gate is formed by several locks linked together. Each of the agencies has the key to its own lock, and not the key to any of the others. Of course, anyone who can open one of the locks can open the gate. This is a nice example of a multiple-user access-control system. It's simple, and it works. You can also make it as complicated as you want, with different locks in parallel and in series. [Ah, a wonderful new use for the switching theory of relay circuits that takes me back to Howard Aiken's switching course in 1953! Boolean switching functions and even bridge networks, where current can flow in either direction in some links, provide for nifty multilock combinations. PGN] ------------------------------ Date: Wed, 5 Jan 2005 12:03:06 -0600 (CST) From: jhhaynes@private Subject: Problems with Chicago-area toll road transponders [Source: Activating I-PASS hits a roadblock; Online demand blamed for delay Virginia Groark, *Chicago Tribune*, 4 Jan 2005; PGN-ed] http://www.chicagotribune.com/technology/chi-0501040029jan04,1,5273675.story ?coll=chi-techtopheds-hed http://www.chicagotribune.com/technology/chi-0501040029jan04,1,5273675.story?coll=chi-techtopheds-hed The Illinois State Toll Highway Authority raised the tolls at 12:01 on New Year's Day 2005 for drivers paying cash, which caused floods on both the phone lines (with typically a 15-minute wait) and the Web site, with 65,000 requests for I-PASS accounts over the weekend. Officials warned that it might take up to eight hours for activated transponders to work. ------------------------------ Date: Tue, 11 Jan 2005 18:39:03 -0500 From: David Tarabar <dtarabar@private> Subject: GPS used to arrest snowplow driver For the past several years, the Massachusetts Highway Department has required that private snow-removal contractors carry a GPS equipped mobile phone. The purpose is to allow the department to better schedule plowing and to verify that the roads are actually being plowed. "The state found another use for the global positioning satellite network ...", according to the *The Boston Globe*, 11 Jan 2005. At 3:45 AM on 10 Jan, a snow-removal truck stopped at a local coffee shop, where the driver ordered coffee and allegedly exposed himself to a female employee. The Highway department tracked a truck from a local depot and by later that day, the driver had been arrested and charged with multiple offenses. ------------------------------ Date: Sat, 15 Jan 2005 19:39:16 +0200 From: Rex Black <rexblack@private> Subject: Re: A Comedy of Errors (Lamport, RISKS-23.66) I don't know about whether all professional programmers would necessarily catch this error, but any programmer doing competent unit testing and/or any tester doing competent input-handling testing would have caught it. Equivalence class partitioning would identify at least three classes of strings: 1. Null string (sometimes valid) 2. Non-null strings that contain no special characters (valid) 3. Non-null strings that contain at least one special characters (valid) 4. Malformed string (always invalid) In each those classes--excepting perhaps the null string--a competent programmer or tester should be able to identify multiple subclasses and other interesting tests (e.g., using boundary value analysis), such as the non-null string of minimal length, the non-null string of maximum length, the non-null string exactly one character longer than the maximum length, a non-null string long enough to overflow a buffer, etc. Since these types of tests tend to be effective at finding bugs during system testing by independent test teams, I conclude that many programmers do not cover these tests during unit testing. With the advent of some of the so-called agile methodologies, that may well change, provided that programmers take the time to study and apply well-established testing techniques. Rex Black Consulting Services, Inc., 31520 Beck Road, Bulverde, TX 78163 USA 1 830 438-4830 www.rexblackconsulting.com rex_black@private ------------------------------ Date: Sat, 15 Jan 2005 00:31:13 +0100 From: Nick Brown <Nick.BROWN@private> Subject: Yet another route map software problem This kind of thing has been discussed in RISKS before (20.62, 23.20), but apparently the problems are still there: 1. Go to http://mappoint.msn.com/DirectionsFind.aspx 2. In the Start section, select "Norway" from the listbox and enter "Haugesund" into the "City" field 3. In the End section, select "Norway" from the listbox and enter "Trondheim" into the "City" field 4. Click on "Get Directions" Interestingly, inverting the cities in the request produces "less spectacular" results. What was fundamentally the same service (Microsoft Expedia Maps, now called MSN MapPoint) figured in article in RISKs 20.62, more than five years ago. ------------------------------ Date: Sat, 15 Jan 2005 12:06:55 -0500 From: Adam Shostack <adam@private> Subject: MapPoint explains Vikings? (Or, that wrong turn at Djupaskarvegen again!) When going from Haugesund, Rogaland, Norway, to Trondheim, S=F8r-Tr=F8ndelag, Norway, be aware that following Microsoft MapPoint's directions, will take you through England, France, Belgium, the Netherlands, Germany, Denmark, Sweden, and finally back into Norway. While this may be culturally sensitive and respectful of historic Viking routing, rooting, or looting, it is somewhat less efficient than other routes, as a quick glance at a map will show. Start: Haugesund, Rogaland, Norway End: Trondheim, S=F8r-Tr=F8ndelag, Norway Total Distance: 1685.9 Miles, Estimated Total Time: 47 hours, 31 minutes (This is listed as the "quickest" route.) [.gif file deleted] ------------------------------ Date: Sun, 16 Jan 2005 16:05:39 -0500 From: Doug McIlroy <doug@private> Subject: Re: Risks of lenient parsing (Horning, RISKS-23.66) Following up on Jim Horning's remarks that rightfully blame the prevalence of bad HTML, which works here but not there, on browsers' silently "fixing" errors, I note that this behavior was officially encouraged: HTML user agents should be liberal except when verifying code. - Berners-Lee, Connolly et al, "HyperText Markup Language Specification - 2.0", Internet Draft, November 28, 1994 Browsers -- the only ubiquitous tools for seeing that a web page works -- are rarely built for verification, and this sentence lets them off the hook. It has always ranked high on my list of misguidances in language design. [Doug's message is right on. Jim's posting created quite a flurry, both in-band and out-of-band. I have selected a few, despite some overlap, which by no means covers the waterfront, but may exhaust the reader. PGN] ------------------------------ Date: Sat, 15 Jan 2005 02:07:48 -0600 (CST) From: Walter Roberson <roberson@private> Subject: Re: Risks of lenient parsing (Horning, RISKS-23.66) In RISKS-23.66, Jim Horning contended that "*all* of the browsers were wrong not to indicate clearly the presence of a syntax error." In my experience, pages *without* HTML syntax errors are quite uncommon. I usually use an older browser that does less automatic fixups of incorrect HTML. If I hand-edit nonconformant HTML to make it compliant, the browser almost always works. I find that an increasing number of sites are insisting on IE6, or Firefox, or Netscape 7, supposedly because "We use advanced HTML features not supported in older browsers". In *every* such case that I have investigated, if I grab the content elsewise and fix its broken HTML, the pages have worked fine on the old browser. Sites almost never fix their HTML in response to my reports. It has become clear to me that requiring IE6 has become a euphemism for "Our HTML is nonconformant and we have no intention of fixing it." ------------------------------ Date: Sat, 15 Jan 2005 12:52:42 +0000 From: Roger Burton West <roger@private> Subject: Re: Risks of lenient parsing (Horning, RISKS-23.66) Mr Horning may find it useful to be aware of the Dillo browser (http://www.dillo.org/), which not only gives detailed information on errors in HTML but uses a clearly-specified set of heuristics in trying to correct them. ------------------------------ Date: Mon, 17 Jan 2005 10:21:29 -0500 From: Jonathan Kamens <jik@private> Subject: Re: Risks of lenient parsing (Horning, RISKS-23.66) I had a "those who fail to learn from history" moment when I read Jim Horning's account of his difficulty tracking down an HTML syntax error because all of the browsers used to display the page with the error silently corrected it. Years ago, early on in the browser wars when Netscape was still king, I heard a similar rant from one of my friends who is an SGML / XML / HTML expert. The very controversial question the browser developers and early adopters were asking then was, should HTML be treated as a structured language which must parse correctly to be displayed, or should it be treated as a markup language which browsers should obey as much as possible even when it's broken? Clearly, the browsers have chosen the latter. As uncomfortable as that decision may make the technology purists among us, it is a reasonable application of Postel's rule to "Be generous in what you accept and conservative in what you generate." Developers who regularly encounter difficulties with HTML syntax errors which the browsers make difficult to locate may wish to avail themselves of one of the numerous free and commercial HTML validation tools that are available. ------------------------------ Date: Mon, 17 Jan 2005 11:01:18 -0500 From: "Russell Smiley" <smiley@private> Subject: Re: Risks of lenient parsing (Horning, RISKS-23.66) > A friendly browser would even have made some > attempt to indicate the approximate location on the page of the error. Personally I'd be rather annoyed if my favourite browser started generating prompts for "general syntax error at line x" on every poorly formed web page out there and I suspect most general users would as well. It seems to me that browsers try to cleanly and silently work around problems in HTML to ease the experience for users who simply don't understand the issues with writing good HTML, or don't want to. In a general sense this seems particularly reasonable when most of the time the error can be worked around without any noticeable problem for the user. However Mr Horning's experience suggests there is a specific class of users who actually need the error reporting to validate the HTML they are generating. Rather than "enhancing" browsers to report all errors as Mr Horning suggests I would suggest that browsers should have a debug mode which is by default disabled to facilitate the present user-friendly experience. When enabled the debug mode could report all HTML errors for the benefit of those users who need to know about such errors. ------------------------------ Date: Sat, 15 Jan 2005 13:45:05 +0100 From: Sander Tekelenburg <tekelenb@private> Subject: Re: Risks of lenient parsing (Horning, RISKS-23.66) > So what is the lesson? The 3 lessons are: 1. There is no excuse for publishing invalid HTML as there are plenty of HTML validators available. (Once you use them you will notice that there are (almost?) no CMS tools, blogs, 'WYSIWYG HTML editors', etc. that output valid HTML. At best they output minor errors (like not encoding ampersands) but usually they'll just output crap, relying on browsers' ESP engines to guess what was meant.) Note that some of those tools, like HTMLTidy, are useful but are not *validators*. 2. When a Web page shows a problem, the first thing to do is make sure its HTML is valid. It's no use wasting time on any other aspect as long as it is not. For some reason most Web designers seem to be unaware of this. 3. You were using the wrong tools. (iCab, see below, would have been a right tool.) > Given the frequency of errors in HTML, it would be unreasonable for > renderers to refuse to display pages with errors. IMO this is open for debate still. Browsers refusing to display invalid HTML would be the ideal solution, as it would force authors to ensure valid HTML. However, I recognise that, given that easily 95% of the Web contains broken HTML, a user agent that would refuse to display such pages would never become popular. It is simply too late now. Users expect Web pages to 'just work'. They expect browsers to guess what the author meant, and to guess right. Still, indicating to the user that a page contains invalid HTML, and that therefore what is rendered is no more than a best guess at what the author intended *would* be realistic. It would be a very useful tool for those who care, and it would not get in the way of those who don't. Give it time, and more users will hopefully begin to realise that indeed it does matter. The Web browser iCab has offered this for many years. A way to make this even more useful, perhaps even to popularise this, might be to have browsers score pages. The less HTML errors, the better the score, thus indicating that the user can be more confident that what is being displayed is what the author intended. If that becomes popular enough, then maybe, just maybe we can finally arrive at a point where users will appreciate browsers that refuse to display invalid Web pages. Probably the right way (both to make it a smooth step from the previous step, and to popularise it) would be to allow users to define the threshold at which their browser should simply refuse to display a page. Of course you would need to come up with a sensible algorithm to be able to score HTML in a useful way. This won't be easy given that 1 error will influence the effect of another error... > We stumbled around blindly because *none* of the browsers we were using > gave any hint that there was a syntax error on the page. There is at least one browser that does contain a HTML syntax checker, and has so for many, many years: iCab. See <http://www.icab.de/>. When it considers a document's HTML to be good, it shows a green smiley in the toolbar. When it considers a document to contain 1 or more errors, the green smiley turns into a red sad face, which you can click to get a list of all the errors it found (including a hint as to what is wrong about it and sometimes even what it probably should have been) and in turn double-clicking individual errors makes it show the document's source code, with the relevant portion highlighted. This tool has been available since about 1998 (provided you have a Mac to run it on). AFAIK to this date no other browser vendor has been smart enough to copy this function. iCab 3.0, which is currently in 'limited public beta testing' phase not only validates HTML 4.0.1 but also XHTML 1.0, CSS 2.1 and javascript. > Each just silently "corrected" the error. Unfortunately, but predictably, > they didn't all "correct" it in the same way, meaning that Peter and his > testers were consistently getting one result, and I was consistently > getting another. Although I agree, IMO you're forgetting an even more (and far more common) danger: that silently fixed HTML errors can easily lead to output that is wrong, but *not obviously wrong*. Also note that this goes beyond just HTML. For instance, many Web sites do not provide any or the correct character repertoire that applies (and sometimes even claim 2 different charsets!), and browsers will often silently guess which character repertoire to use. This can lead to outright nonsense which is easily recognised, but can just as well lead to just the odd character being wrong. You bet that in some cases that 'wrong' character could make perfect sense and can thus go by undiscovered, even though it could change the meaning of the content completely. AFAIK no browser will warn the user in this case. So use iCab, and/or put pressure on the makers of your favourite browser to make their product useful. Sander Tekelenburg <http://www.euronet.nl/~tekelenb/> ------------------------------ Date: Tue, 11 Jan 2005 11:31:25 -0800 From: Rob Slade <rslade@private> Subject: Copyright and reverse engineering > http://www.zdnet.com.au/news/security/0,2000061744,39176657,00.htm > > A French security researcher who published exploit codes that could > take advantage of bugs in an anti-virus application, could be > imprisoned for violation of copyright laws. I warned ya. OK, well not quite the same situation, but on page 21 of "Software Forensics" I noted that this type of situation might one day result in a malware author challenging evidence obtained by forensic examination on the basis of the laws supposedly supporting copyright by inveighing against reverse engineering. rslade@private slade@private rslade@private http://victoria.tc.ca/techrev or http://sun.soci.niu.edu/~rslade ------------------------------ Date: Sun, 16 Jan 2005 18:21:10 -0500 From: Steven Branigan <steveb@private> Subject: Re: High Tech Crimes Revealed" (Slade review, RISKS-23.65) I am honored by the fact that Robert Slade took the time to do a review of my book, "High Tech Crimes Revealed", back on December 29th, 2004. It covers a few high tech crime cases from "inside the investigation", based upon actual cases with which I was involved. I believe that these stories are very relevant in today's society. We need just look at the recent story about hackers breaking into T-Mobile to read e-mails of an ongoing investigation to see that hackers are still getting past computer security. http://www.cnn.com/2005/LAW/01/12/cellular.hacker.ap/ I just wanted to address a couple of small points that I spoke with Robert about prior to his publishing this review. (1) steganography The quote from my book is... "Rumors persist that Al-Qaeda style terrorist groups have used steganography to hide their communications out in the open. Using steganography, a person can hide a secret message inside a picture that is sent via e-mail or even posted on a website. All that is needed from the person receiving the picture is to extract the hidden message from it." Rumors do persist that terrorist have looked at using steganography for clandestine communication. http://www.fitug.de/news/newsticker/old/2001/newsticker200901125229.html http://www.heise.de/tp/r4/artikel/11/11004/1.html Let me state that I have not seen any conclusive evidence that steganography has been used for terrorist communications. I do wish to point out, though, that some in the government are concerned about it and are not looking into it. (2) Salami scam I had a discussion with Robert and I believe that his view is that the salami scam is all hype because there are very few documented cases of it. I respect that point of view, but I believe that the following documented cases are sufficient to be concerned about it as a potential crime. http://www.collyerbristow.com/site/default.asp?s=55&cID=301&ctID=13&bhcp=1 http://www.nwfusion.com/newsletters/sec/2002/01467137.html ------------------------------ Date: Mon, 17 Jan 2005 11:14:44 -0500 From: Paul Robinson <ohshitidontknow@private> Subject: Re: A Kafka day at the Los Angeles traffic ticket office (R.23-66) [Open letter to Mark Frauenfelder:] I saw the discussion of your problem with your wife's traffic ticket which was also reported in RISKS-23.66. I am not a lawyer but I have some idea on what your wife needs to do if you can't resolve the ticket because the system won't record it: Call (or preferably write) the headquarters office for the district attorney for Los Angeles County. If you write, you explain the situation; if you call you ask to speak to the district attorney or get an appointment,.saying you need to discuss the disposition of a court case. You do not inform the secretary of what the case is unless she says she has authority to negotiate a plea bargain herself (which she won't of course). You'll get some lawyer in the office but that's fine, because that's what you want.. If you can get a lawyer on the phone or you get an appointment, you explain the circumstances of the situation and ask them to agree to dismiss the charge and not prosecute this particular ticket because the case office is not posting the ticket and you can't be put in a position where you are "twisting, turning in the wind," waiting for an unknown and unknowable filing to be made which places you in jeopardy of even more serious criminal penalties when you can't get the current one resolved. If they won't or you can't get someone, you file suit in Superior Court against the District Attorney's office (you will probably have to sue the D.A. personally by name) for a writ of mandamus prohibiting them from prosecuting the original ticket. You may even be able to sue for damages but I think all you're interested in is to get rid of the matter, either by converting it off of a moving violation or getting it dismissed. I don't think it would be that difficult to file for an order even without a lawyer since you're only trying to solve the problem and the government, by its incompetence or misconduct is placing you in a position in which you are being denied the right to a constitutionally guaranteed speedy trial and quite possibly to equal.protection and possibly other issues. Even if you don't get the order you've got grounds to have any potential penalty for not paying the ticket and not appearing canceled. ------------------------------ Date: 29 Dec 2004 (LAST-MODIFIED) From: RISKS-request@private Subject: Abridged info on RISKS (comp.risks) The RISKS Forum is a MODERATED digest. Its Usenet equivalent is comp.risks. => SUBSCRIPTIONS: PLEASE read RISKS as a newsgroup (comp.risks or equivalent) if possible and convenient for you. Mailman can let you subscribe directly: http://lists.csl.sri.com/mailman/listinfo/risks Alternatively, to subscribe or unsubscribe via e-mail to mailman your FROM: address, send a message to risks-request@private containing only the one-word text subscribe or unsubscribe. You may also specify a different receiving address: subscribe address= ... . You may short-circuit that process by sending directly to either risks-subscribe@private or risks-unsubscribe@private depending on which action is to be taken. 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Instead, use an alternative address from which you NEVER send mail! => The INFO file (submissions, default disclaimers, archive sites, copyright policy, PRIVACY digests, etc.) is also obtainable from <http://www.CSL.sri.com/risksinfo.html> The full info file may appear now and then in future issues. *** All contributors are assumed to have read the full info file for guidelines. *** => SUBMISSIONS: to risks@private with meaningful SUBJECT: line. *** NOTE: Including the string "notsp" at the beginning or end of the subject *** line will be very helpful in separating real contributions from spam. *** This attention-string may change, so watch this space now and then. => ARCHIVES: ftp://ftp.sri.com/risks [subdirectory i for earlier volume i] <http://www.risks.org> redirects you to Lindsay Marshall's Newcastle archive http://catless.ncl.ac.uk/Risks/VL.IS.html gets you VoLume, ISsue. Lindsay has also added to the Newcastle catless site a palmtop version of the most recent RISKS issue and a WAP version that works for many but not all telephones: http://catless.ncl.ac.uk/w/r <http://the.wiretapped.net/security/info/textfiles/risks-digest/> . ==> PGN's comprehensive historical Illustrative Risks summary of one liners: <http://www.csl.sri.com/illustrative.html> for browsing, <http://www.csl.sri.com/illustrative.pdf> or .ps for printing ------------------------------ End of RISKS-FORUM Digest 23.67 ************************
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