November 2021 - wlug - list.wlug.org.nz

meeting next Monday
by Peter Reutemann 18 Nov '21

18 Nov '21

Hi everyone We have a WLUG meeting next week on Monday: 'For the last meeting of the year, let's have general get-together. Ian Stewart will demo the latest Ubuntu 21.10 and Peter Reutemann will try to show what you can use the frp fast reverse proxy for (https://github.com/fatedier/frp) And of course, general Linux related troubleshooting and questions answered.' -- source: https://www.meetup.com/WaikatoLinuxUsersGroup/events/274861098/ This is once again an online event, so make sure to RSVP on meetup to get the link (you only need a browser). Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Latency Numbers Every Programmer Should Know
by Lawrence D'Oliveiro 17 Nov '21

17 Nov '21

Somebody did a nice chart a while back <https://gist.github.com/hellerbarde/2843375> of the time it takes to perform many common data transfer operations on contemporary hardware. And note the multi-part figure, where the basic unit in each block is a bit more than an order of magnitude greater than the one in the previous block. And if the figure isn’t dramatic enough, a commenter has said “let’s multiply all the numbers by a billion” (just to bring them into more human-comprehensible scales), and then liken them to common things that people do, from making a cup of coffee, all the way up to completing a bachelor’s degree.

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Scientists Send Data Using Nuclear Radiation
by Lawrence D'Oliveiro 16 Nov '21

16 Nov '21

A research group has used fast neutrons <https://www.theregister.com/2021/11/15/wireless_information_transfer_with_f…> as a communication channel, to send legible data between a transmitter and a receiver. Their proof of concept is very low-bandwidth and requires a lot of complicated equipment, but at least it does show (safety issues aside) that it is theoretically possible. The issue with high-energy subatomic particles is, how do you turn them on and off at will -- i.e. modulate the intensity of the beam to convey information? This group used some kind of shutter system (“neutron chopper”) in conjunction with some quantity of radioactive californium-252 as their neutron source. But they mention that someone else has come up with a device that is basically a particle accelerator on a chip, able to produce a stream of neutrons from non-radioactive starting components on demand.

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Microsoft Fixes An Issue
by Lawrence D'Oliveiro 16 Nov '21

16 Nov '21

The latest Windows 11 update <https://www.theregister.com/2021/11/15/windows_11_insiders_bug_fixes/> gets ever closer to perfection. I like this one: We fixed an issue that prevents your device from starting up, and it becomes unresponsive because of licensing API calls. Because what would that good old “enrichment of the user experience” be like without licensing API calls ... The writer’s verdict on the new OS sounds more like damning with faint praise: We have been running Windows 11 for daily work since official release and are happy to report that it is usable and stable in our experience so far, though useful improvements over its predecessor are hard to identify.

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DDR4 memory protections are broken wide open by new Rowhammer technique
by Peter Reutemann 16 Nov '21

16 Nov '21

'Rowhammer exploits that allow unprivileged attackers to change or corrupt data stored in vulnerable memory chips are now possible on virtually all DDR4 modules due to a new approach that neuters defenses chip manufacturers added to make their wares more resistant to such attacks. Rowhammer attacks work by accessing—or hammering—physical rows inside vulnerable chips millions of times per second in ways that cause bits in neighboring rows to flip, meaning 1s turn to 0s and vice versa. Researchers have shown the attacks can be used to give untrusted applications nearly unfettered system privileges, bypass security sandboxes designed to keep malicious code from accessing sensitive operating system resources, and root or infect Android devices, among other things. All previous Rowhammer attacks have hammered rows with uniform patterns, such as single-sided, double-sided, or n-sided. In all three cases, these “aggressor” rows—meaning those that cause bitflips in nearby “victim” rows—are accessed the same number of times. Research published on Monday presented a new Rowhammer technique. It uses non-uniform patterns that access two or more aggressor rows with different frequencies. The result: all 40 of the randomly selected DIMMs in a test pool experienced bitflips, up from 13 out of 42 chips tested in previous work from the same researchers.' -- source: https://arstechnica.com/gadgets/2021/11/ddr4-memory-is-even-more-susceptibl… Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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topics for next month?
by Peter Reutemann 15 Nov '21

15 Nov '21

Hi everyone Next month will be the last meeting for the year and I'm once again looking for presenters. I can give a short introduction/show'n'tell of frp (fast reverse proxy) and what it can be used for: https://github.com/fatedier/frp Who else is willing to talk about something? It doesn't have to be admin-type stuff at all, but instead useful applications that you use/have come across. If you have something, even just for 5-10 min, please reply in this thread or contact me off-list. Have a great and safe weekend! Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Ask Slashdot: Why Is Firefox Losing Users?
by Peter Reutemann 05 Nov '21

05 Nov '21

'This weekend finds some long-time Slashdot readers debating why research shows Firefox losing market share. Long-time Slashdot reader chiguy shares one theory: "Firefox keeps losing users, according to this rant, because it arrogantly refuses to listen to its users." Slashdot reader BAReFO0t countered that that can't be the reason, "because Google does that too." (They blame Chrome's "feature" addition treadmill, where "they keep adding stupid kitchen sinks for the sole and only purpose to make others unable to keep up.") Long-time Slashdot reader Z00L00K thinks that "All those totally unnecessary UI changes are what REALLY annoys users. Not only the immediately visible things in the header but also the renaming of items in the menus just bugs people." But long-time Slashdot reader AmiMoJo argues that "the most popular browser, Chrome, has all those things. In fact all the browsers that are more popular than Firefox do, so the idea that those are unpopular and driving people away doesn't really hold up... Firefox's decline is mostly due to Chrome just being really good, and [Firefox] not having a decent mobile version." I'm still a loyal Firefox user. (Although the thing that annoyed me was when Firefox suddenly changed the keyboard shortcut for copying a link from CNTRL-A to CNTRL-L.) The "rant" at ItsFoss argues that Firefox's original sin was in 2009 when it decided to move tabs to the top of the browser, and when favorite features could no longer be re-enabled in Firefox's about:config file. But that's what I like about Firefox -- at it's best, it's ultimately customizable, with any feature you want easily enabled in what's essentially an incredibly detailed "preferences" menu. Maybe other browsers are just better at attracting new users through purely mechanical advantages like default placement on popular systems? Long-time Slashdot reader zenlessyank is also a long-time Firefox user -- "Been using it since Netscape" -- and countered all the doubters with a comment headlined "Firefox rocks!" "Doesn't matter to me how many other users there are or aren't I will still use it as long as it stays updated." But what are your thoughts? Feel free to share your own opinions and experiences with Firefox in the comments.' -- source: https://news.slashdot.org/story/21/09/12/181257 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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The Booming Underground Market for Bots That Steal Your 2FA Codes
by Peter Reutemann 04 Nov '21

04 Nov '21

'The bots convincingly and effortlessly help hackers break into Coinbase, Amazon, PayPal, and bank accounts. From a report: The call came from PayPal's fraud prevention system. Someone had tried to use my PayPal account to spend $58.82, according to the automated voice on the line. PayPal needed to verify my identity to block the transfer. "In order to secure your account, please enter the code we have sent your mobile device now," the voice said. PayPal sometimes texts users a code in order to protect their account. After entering a string of six digits, the voice said, "Thank you, your account has been secured and this request has been blocked. Don't worry if any payment has been charged to your account: we will refund it within 24 to 48 hours. Your reference ID is 1549926. You may now hang up," the voice said. But this call was actually from a hacker. The fraudster used a type of bot that drastically streamlines the process for hackers to trick victims into giving up their multi-factor authentication codes or one-time passwords (OTPs) for all sorts of services, letting them log in or authorize cash transfers. Various bots target Apple Pay, PayPal, Amazon, Coinbase, and a wide range of specific banks. Whereas fooling victims into handing over a login or verification code previously would often involve the hacker directly conversely with the victim, perhaps pretending to be the victim's bank in a phone call, these increasingly traded bots dramatically lower the barrier of entry for bypassing multi-factor authentication.' -- source: https://yro.slashdot.org/story/21/11/03/1842245 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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Microsoft's Edge Browser for Linux is Now Available for All Users
by Peter Reutemann 03 Nov '21

03 Nov '21

'A year after releasing the first preview build of its Chromium-based Edge browser for Linux, Microsoft is announcing its general availability. From a report: The new release supports a variety of Linux distributions, including Ubuntu, Debian, Fedora and openSUSE. Microsoft announced Linux on Edge's availability milestone during the first day of its Ignite IT Pro conference. As of the release of Edge for Linux to the "stable" (mainstream user) channel, Edge is now available on Windows, Mac, iOS, Android and Linux. As it did when introducing the new Edge on macOS, Microsoft has been positioning Edge on Linux as more of an offering for IT pros and developers who want to test web sites than as a browser for "normal" users on those platforms. However, any user on any supported platform can use the new Edge.' -- source: https://linux.slashdot.org/story/21/11/02/1627250 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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'Trojan Source' Bug Threatens the Security of All Code
by Peter Reutemann 02 Nov '21

02 Nov '21

'"Virtually all compilers -- programs that transform human-readable source code into computer-executable machine code -- are vulnerable to an insidious attack in which an adversary can introduce targeted vulnerabilities into any software without being detected," warns cybersecurity expert Brian Krebs in a new report. An anonymous reader shares an excerpt: Researchers with the University of Cambridge discovered a bug that affects most computer code compilers and many software development environments. At issue is a component of the digital text encoding standard Unicode, which allows computers to exchange information regardless of the language used. Unicode currently defines more than 143,000 characters across 154 different language scripts (in addition to many non-script character sets, such as emojis). Specifically, the weakness involves Unicode's bi-directional or "Bidi" algorithm, which handles displaying text that includes mixed scripts with different display orders, such as Arabic -- which is read right to left -- and English (left to right). But computer systems need to have a deterministic way of resolving conflicting directionality in text. Enter the "Bidi override," which can be used to make left-to-right text read right-to-left, and vice versa. "In some scenarios, the default ordering set by the Bidi Algorithm may not be sufficient," the Cambridge researchers wrote. "For these cases, Bidi override control characters enable switching the display ordering of groups of characters." Bidi overrides enable even single-script characters to be displayed in an order different from their logical encoding. As the researchers point out, this fact has previously been exploited to disguise the file extensions of malware disseminated via email. Here's the problem: Most programming languages let you put these Bidi overrides in comments and strings. This is bad because most programming languages allow comments within which all text -- including control characters -- is ignored by compilers and interpreters. Also, it's bad because most programming languages allow string literals that may contain arbitrary characters, including control characters. "So you can use them in source code that appears innocuous to a human reviewer [that] can actually do something nasty," said Ross Anderson, a professor of computer security at Cambridge and co-author of the research. "That's bad news for projects like Linux and Webkit that accept contributions from random people, subject them to manual review, then incorporate them into critical code. This vulnerability is, as far as I know, the first one to affect almost everything." The research paper, which dubbed the vulnerability "Trojan Source," notes that while both comments and strings will have syntax-specific semantics indicating their start and end, these bounds are not respected by Bidi overrides. [...] Anderson said such an attack could be challenging for a human code reviewer to detect, as the rendered source code looks perfectly acceptable. "If the change in logic is subtle enough to go undetected in subsequent testing, an adversary could introduce targeted vulnerabilities without being detected," he said. Equally concerning is that Bidi override characters persist through the copy-and-paste functions on most modern browsers, editors, and operating systems.' -- source: https://it.slashdot.org/story/21/11/01/2147254 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 (office) +64 (7) 577-5304 (home office) http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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