March 2024 - wlug - list.wlug.org.nz

New Attack On AI Bots: Prompt Injection
by Lawrence D'Oliveiro 01 Jul '26

01 Jul '26

A Twitter bot account run by a company that posts remote job listings was programmed to respond to tweets directed to it with general inoffensive comments touting the positive aspects of remote work. However <https://arstechnica.com/information-technology/2022/09/twitter-pranksters-d…>, some other Twitter users discovered that if they began their tweet with directives to “ignore previous instructions”, they could get the bot to say just about anything. And much hilarity ensued. Basically, the way the bot program works is it begins with some standard instructions on what to say, provided by the people who set up the account, to which is appended whatever tweet content was sent to the bot by the other user. This is then processed by the AI system to produce a response. This attack has been dubbed “prompt injection”, by analogy with “SQL injection” and other similar attacks on non-AI systems. But whereas those attacks can be blocked using basic, well-known syntactic quoting techniques, there seem to be no easy equivalents for stopping an AI paying attention to instructions it should not be obeying.

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Weta Digital’s Technology Division Sold To US Firm
by Lawrence D'Oliveiro 01 Aug '25

01 Aug '25

Let me see if I understand this article <https://www.nzherald.co.nz/business/sir-peter-jackson-to-sell-weta-digital-…> correctly: the part of Weta Digital that used to develop the in-house 3D graphics/effects tools that they use in all those movies is being sold to US-based Unity Software. The part that is left will be called “WetaFX”, and will become a customer of Unity for the use of those tools, no longer doing its own development in-house. By the way, I’ve been looking at the Unity site <https://unity.com/>, and it looks like all their products are rentware (subscription-based).

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New systemd update will bring Windows’ infamous Blue Screen of Death to Linux
by Peter Reutemann 18 Nov '24

18 Nov '24

'Windows' infamous "Blue Screen of Death" is a bit of a punchline. People have made a hobby of spotting them out in the wild, and in some circles, they remain a byword for the supposed flakiness and instability of PCs. To this day, networked PCs in macOS are represented by beige CRT monitors displaying a BSOD. But the BSOD is supposed to be a diagnostic tool, an informational screen that technicians can use to begin homing in on the problem that caused the crash in the first place; that old Windows' BSOD error codes were often so broad and vague as to be useless doesn't make the idea a bad one. Today, version 255 of the Linux systemd project honors that original intent by adding a systemd-bsod component that generates a full-screen display of some error messages when a Linux system crashes. The systemd-bsod component is currently listed as "experimental" and "subject to change." But the functionality is simple: any logged error message that reaches the LOG_EMERG level will be displayed full-screen to allow people to take a photo or write it down. Phoronix reports that, as with BSODs in modern Windows, the Linux version will also generate a QR code to make it easier to look up information on your phone.' -- source: https://arstechnica.com/gadgets/2023/12/linux-distros-are-about-to-get-a-ki… Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, Hamilton, NZ Mobile +64 22 190 2375 https://www.cs.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Juice TV Hiccup
by Lawrence D'Oliveiro 15 Oct '24

15 Oct '24

Currently when I switch to FreeView Channel 200, it shows a frozen image with the text “Cinegy” and “Demo Version” on it. Searching for that name takes me to a site that talks about “software defined television”. Either their product licence has expired, or they never had one in the first place ...

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List Of IPTV Resources
by Lawrence D'Oliveiro 22 Sep '24

22 Sep '24

This user <https://github.com/iptv-org> just popped up in my GitHub feed. One repo <https://github.com/iptv-org/iptv> claims to be a list of links to over 8000 streaming TV channels from nations all over the world, while the other is a list of tools*, providers and other resources. Do be aware it’s a bit of a mixed bag: yes, there are legitimate channels (no encryption so far that I have noticed), but also some dubious-looking links. *Oddly, FFmpeg and youtube-dl aren’t in the list.

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Tip For Repairing Ancient Linux Installations
by Lawrence D'Oliveiro 02 Apr '24

02 Apr '24

Here’s the scenario: there is a malfunctioning server running a really ancient Linux installation (e.g. 2.6.x-series kernel). You boot up with a reasonably recent copy of SystemRescue, mount the machine’s filesystem, try to chroot into it and run a shell ... and it segfaults. Seems there has been a subtle incompatible change in Linux kernel behaviour since those times, to do with the disabling of something called the “vsyscall” mechanism (which is specific to 64-bit x86-based machines, I understand). This was supposed to be a way to speed up certain commonly-executed system calls (I think getting the system time was one of them) by allowing direct transfers to certain entry points with fixed memory addresses for invoking them. It was later decided this was a bad idea (I think for security reasons). The mechanism has not been completely removed (yet), but nowadays it is disabled by default. To get around this, you need to boot SystemRescue with a change to the kernel command-line parameters, adding this item vsyscall=emulate After you get to a shell, you can confirm that this setting is in effect by checking the /proc/self/maps file (the memory mappings for your own process). At the bottom, there should be an entry with “[vdso]” in it, and below that another line with “[vsyscall]”. The presence of the latter line indicates that vsyscall emulation is in effect. This is not present when I check a process on my own machine, for example. Linus is legendary for being a stickler for never, ever breaking backward compatibility for userland. So the reasons for turning this off must have been pretty compelling, for him to agree to it. But the compromise is, it’s still there to be enabled if you really, really need it. There’s a bit more technical info here <https://0xax.gitbooks.io/linux-insides/content/SysCall/linux-syscall-3.html>, if you are interested. By the way, the above page is part of a book beginning here <https://0xax.gitbooks.io/linux-insides/content/>, about the insides of the Linux kernel. The whole book seems to be accessible from that link, but if you step up a level, the site doesn’t seem to have any idea about the existence of that book.

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Uncle Sam’s Had It Up To Here With “Unforgivable” SQL Injection Flaws
by Lawrence D'Oliveiro 27 Mar '24

27 Mar '24

We all know SQL injection attacks are an ongoing problem <https://www.theregister.com/2024/03/26/fbi_cisa_sql_injection/>. What interested me about this article is this part: Software vendors have been advised to use parameterized queries with prepared statements to mitigate SQL injection vulnerabilities. According to the authorities, these allow user-input data to be separated from SQL queries and "better embody a secure by design approach" compared to input sanitization techniques. These are deployed by some vendors, but were branded "brittle" by CISA and the FBI. They said they're also difficult to deploy on a large scale and are more easily bypassed. Funny, that. Every time I post examples of how I dynamically construct SQL query strings with proper quoting of user input, I get yelled at and told to use “parameterized queries” and “prepared statements”, or even an ORM. Yet here we have the security experts saying that that is not a good solution, just like I thought all along.

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Mozilla’s privacy service drops a provider with ties to people-search sites
by Peter Reutemann 26 Mar '24

26 Mar '24

'Mozilla's Monitor Plus, a service launched by the privacy-minded tech firm in February, notes on its pitch page that there is "a $240 billion industry of data brokers selling your private information for profit" and that its offering can "take back your privacy." Mozilla's most recent move to protect privacy has been to cut out one of the key providers of Monitor Plus' people-search protections, Onerep. That comes after reporting from security reporter Brian Krebs, who uncovered Onerep CEO and founder Dimitri Shelest as the founder of "dozens of people-search services since 2010," including one, Nuwber, that still sells the very kind of "background reports" that Monitor Plus seeks to curb. Shelest told Krebs in a statement (PDF) that he did have an ownership stake in Nuwber, but that Nuwber has "zero cross-over or information-sharing with Onerep" and that he no longer operates any other people-search sites. Shelest admitted the bad look but said that his experience with people search gave Onerep "the best tech and team in the space." Brandon Borrman, vice president of communications at Mozilla, said in a statement that while "customer data was never at risk, the outside financial interests and activities of Onerep’s CEO do not align with our values." Mozilla is "working now to solidify a transition plan," Borrman said. A Mozilla spokesperson confirmed to Ars today that Mozilla is continuing to offer Monitor Plus, suggesting no pause in subscriptions, at least for the moment.' -- source: https://arstechnica.com/gadgets/2024/03/mozillas-privacy-service-drops-a-pr… Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, Hamilton, NZ Mobile +64 22 190 2375 https://www.cs.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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decrypting PDFs
by Peter Reutemann 22 Mar '24

22 Mar '24

Hi everyone I've long had a problem with being unable to open some PDFs that could be either viewed on Windows or on Google Drive. For some reason, some PDFs appear to be encrypted (but not requiring a password??). Today, I found an approach that allows me to access these files also on my Linux machine using pdftk. pdftk allows you to decrypt PDFs by supplying a password (https://www.ubuntumint.com/remove-password-from-pdf-on-linux/) pdftk <protected>.pdf input_pw <password> output <new>.pdf However, the following seemed to work on these weird PDF files, without having to supply a password: pdftk <protected>.pdf output <new>.pdf And now my PDF viewers (okular, xreader, etc) no longer complain that they can't open the file. :-) Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, Hamilton, NZ Mobile +64 22 190 2375 https://www.cs.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Formula 1 Chief Appalled to Find Team Using Excel to Manage 20,000 Car Parts
by Lawrence D'Oliveiro 21 Mar '24

21 Mar '24

<https://arstechnica.com/cars/2024/03/formula-1-chief-appalled-to-find-team-…>: The Williams car build workbook, with roughly 20,000 individual parts, was "a joke," Vowles recently told The Race. "Impossible to navigate and impossible to update." This colossal Excel file lacked information on how much each of those parts cost and the time it took to produce them, along with whether the parts were already on order. ... Banks cited Tim Worstall's 2013 contention that Excel could be "the most dangerous software on the planet." Back then, international investment bankers were found manually copying and pasting Excel between Excel sheets to do their work, and it raised alarm.

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