1. Can you get root with only a cigarette lighter?
Total comment counts : 31
Summary
In his article, David Buchanan discusses the creative process of hardware fault injection (HFI), a technique used for exploiting software vulnerabilities when bugs are scarce. He explains various forms of fault injection—including electromagnetic pulses and glitches—and acknowledges that traditional HFI often requires expensive specialized equipment. However, Buchanan highlights affordable alternatives, such as using an RP2040-based device and even a piezo-electric BBQ igniter for electromagnetic fault injection.
Motivated by the upcoming Nintendo Switch 2 announcement and inspired by low-budget EMFI techniques, Buchanan decides to experiment with an old Samsung laptop. He targets the laptop’s DDR bus, aiming to induce faults that could lead to local privilege escalation. Using minimal hardware—specifically a resistor and a wire connected to a data pin—he successfully induces memory errors by activating a nearby piezo-electric lighter.
Buchanan notes a specific instance where a bit flip occurs during the process, indicating some unpredictability in fault injection. He concludes by detailing his intentions to create a sandbox escape exploit in CPython as a demonstration of his findings, emphasizing the broader techniques and strategies of hardware exploitation rather than focusing on the intricate specifics.
Top 1 Comment Summary
The article discusses the aim of achieving root access on the Switch 2, using a proof of concept (POC) based on Linux. The focus is not on identifying a significant security vulnerability but on restoring true ownership of the hardware while ensuring that TPM and game ring 0 anti-cheat systems remain intact.
Top 2 Comment Summary
The article discusses a vulnerability involving electrostatic bit flipping that can potentially corrupt memory pointers during read or write operations. Historically, there was a belief that if an attacker had physical access to a device, security was compromised. However, advancements like Trusted Platform Modules (TPMs) and trusted execution environments have changed this perspective, enabling secure operations even under physical access. The author speculates on future experimentation to achieve similar outcomes without the need for soldering, suggesting it may be complex but could potentially involve bit manipulation through external triggers like clicking a lighter. Overall, the next phase of experimentation promises to be intriguing.
2. How do HTTP servers figure out Content-Length?
Total comment counts : 20
Summary
The article discusses the simplicity of the HTTP 1.1 protocol, highlighting its structure, including the request line, headers, and message body. It features a Go program as a demonstration of sending HTTP responses. One key focus is on the Content-Length header and how the server determines response lengths, potentially needing to keep entire responses in memory. However, it explains that if a response exceeds a certain size, chunked transfer encoding is used, allowing the data to be sent in parts rather than requiring the entire response to be stored in memory at once. This process involves sending the length of each chunk in hexadecimal format, which is essential for efficient data transfer. The article also mentions that HTTP/2 and HTTP/3 do not support chunked encoding due to their differing streaming mechanisms and emphasizes the underlying complexities and automatic handling in Go’s http package.
Top 1 Comment Summary
The article discusses how the Go standard library’s HTTP servers determine the Content-Length header. The author compares it to other languages’ HTTP server implementations, noting three common approaches: explicitly defining Content-Length, using a single write operation for easy length calculation, or enabling manual chunking. The author expresses unfamiliarity and uncertainty regarding the automatic chunking approach described in the article.
Top 2 Comment Summary
The article discusses the importance of optimizing web page and content sizes to minimize the number of data packets required for transmission, which can enhance speed. It references the minimalist design of Google’s front page, which historically fit within a single packet. The article also mentions a notable book by the Yahoo Exceptional Performance Team that provided guidance for web systems administrators, although its relevance has diminished in recent years. A link to the book is included for further reading.
3. Fast B-Trees
Total comment counts : 18
Summary
The article discusses the performance of different data structures used in scripting languages, focusing on hashmaps (like Python dicts and JavaScript objects) and ordered data structures such as b-trees. While hashmaps are widely used, they come with disadvantages, whereas b-trees do not, albeit typically being slower. The author compares their lookup speeds through various benchmarks, emphasizing the importance of test conditions in producing different performance outcomes.
Initial benchmarks showed b-trees performing poorly in terms of lookup speeds compared to hashmaps. However, refinement of the benchmarks revealed that hashmaps might slow down significantly when looking up keys with dependencies, while b-trees maintained their speed. This difference stems from the efficiency of speculative execution in hashmaps, which allows for faster processing of multiple lookups due to their predictable nature.
The article argues that benchmarks should measure both throughput and latency, which clarifies discrepancies in performance expectations. It suggests that while b-trees can struggle with string keys due to needing additional cache lookups for comparisons, hashmaps efficiently handle them.
Ultimately, the findings suggest that optimizing data structures for specific use cases (like strings with common prefixes) may provide significant performance benefits, highlighting the nuanced performance characteristics of these data structures in real-world applications.
Top 1 Comment Summary
The article discusses the performance differences between hash tables and B-trees regarding lookup timings, specifically when using the rdtscp instruction. It explains that rdtscp acts as an execution barrier, hindering the ability for successive lookups to overlap efficiently, which negatively impacts hash tables more than B-trees. This is contrasted with rdtsc, which does not impose such barriers.
The article notes that B-trees do not benefit as much from overlapping adjacent lookups due to data-dependent branches causing mispredictions in tree access paths. While mispredictions can hinder performance, in larger maps, future iterations can still be useful because accessing the correct data locations helps in fetching subsequent nodes efficiently. However, the complexity of instruction cycles during lookups limits overlapping execution benefits.
Ultimately, B-trees improve performance significantly with linear searches that are optimized, such as having fewer instructions per comparison or employing vectorized searches.
Top 2 Comment Summary
The article expresses appreciation for documenting failed engineering experiments, similar to reporting null results in science. It highlights that sharing these failures can prevent others from repeating the same mistakes. The author argues that if only successes were shared, individuals would continually have to rediscover failures on their own.
4. Show HN: Visualization of website accessibility tree
Total comment counts : 11
Summary
The article highlights the importance of creating accessible web applications and introduces ARIA DevTools, a tool that helps developers identify accessibility issues by simulating how screen readers present web content. It enables users to find missing ARIA labels, misused ARIA roles, and incomplete keyboard support easily. The tool is open-source and available on GitHub.
The article also mentions the accessibility tree feature in the browser’s inspection tools and notes some limitations, particularly with the Shadow DOM in certain applications. Additionally, it provides a list of other accessibility tools and resources, including Accessibility Insights for Web, WAVE Evaluation Tool, and WCAG Color Contrast Checker, which assist in finding and fixing accessibility problems. Overall, the article emphasizes the need for tools that aid in testing for web accessibility, making it easier for developers and testers to create inclusive websites.
Top 1 Comment Summary
The article discusses a useful tool for training and spot-checking accessibility, particularly in relation to screen readers. It emphasizes the importance of helping non-technical stakeholders understand accessibility concepts, as many focus only on meeting compliance requirements rather than genuinely improving accessibility.
Top 2 Comment Summary
The article expresses appreciation for a project and requests the capability to run it within iframes, emphasizing its potential use in Storybook/Playroom. It includes a link to a Firefox addon related to ARIA DevTools.
5. Google’s AI thinks I left a Gatorade bottle on the moon
Total comment counts : 37
Summary
The article discusses Google’s NotebookLLM, an AI podcast generator that creates podcasts based on web pages or documents. Although the tool performs well, it is susceptible to manipulation. The author modified their website to provide misleading information, producing a humorous podcast about the US Space Program. This highlights a broader issue where AI could be misled by intentionally deceptive content online.
The author explains that NotebookLLM can be easily directed with fake notes, achieving a 10/10 steerability rating. They suggest that while it’s fun to create silly content for children, intentionally misleading AI carries risks, as the misinformation can propagate across Google’s services. They note that the GoogleOther user agent can be used to serve falsified data to Google’s bots, but caution against this action as it could impact other Google properties. The moon story was subsequently removed to avoid spreading false information.
Top 1 Comment Summary
The article discusses an attack on NotebookLM, which only affects users who intentionally create a Notebook with the attack page’s URL. The author also shares a recent experiment involving Google Gemini, where they queried it about a young whale named “Teresa T” that frequented Pillar Point Harbor. The result confirmed the name, noting that earlier responses didn’t credit the author, but subsequent attempts did. A link to further details is provided.
Top 2 Comment Summary
The author shares their experience of revitalizing a year-old unfinished fiction story by turning it into a podcast. Hearing two people passionately discuss and engage with the themes and characters of the story has inspired the author to continue writing.
6. Ants learned to farm fungi during a mass extinction
Total comment counts : 10
Summary
The article discusses the ancient agricultural practices of ants, which predate human agriculture by millions of years. Various ant species have developed symbiotic relationships with specific fungi, providing nutrients and harvesting them as food. Leafcutter ants exemplify this sophisticated partnership by cutting leaves to cultivate fungi. A recent study involving a team of researchers analyzed the DNA of 475 fungi and 276 ant species to trace the evolution of their cooperation.
The study reveals that this relationship likely began after the mass extinction event that ended the age of dinosaurs, a time when only fungi thrived due to adverse environmental conditions. The researchers found that most species engaging in organized farming emerged around 35 million years later, linked to climate changes that affected tropical environments. This comprehensive analysis, using over 2,000 genes, provides insight into how ants developed their agricultural practices in response to ecological opportunities following the extinction.
Top 1 Comment Summary
The article recalls an episode from the 1980s featuring Sir David Attenborough, where he explores a termite mound, going six feet underground. It highlights the termites’ role as fungus farmers, which they use to feed their large queen. While this specific clip does not show the fungus farming, it mentions that the practice is described in the same program. An edited version features Attenborough revisiting a mound and discussing fungus farming, with a link to the video included.
Top 2 Comment Summary
David speculated on the possibility of humans surviving by consuming mushrooms instead of facing extinction, which inspired him and Joshua Pearce to research and author the book Feeding Everyone No Matter What. More information can be found at their website.
7. Task-Switching Experiment (2015)
Total comment counts : 10
Summary
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Top 1 Comment Summary
The article discusses potential bias in tests performed in a fixed order, which can be influenced by factors like training or exhaustion. It suggests that varying the order of tests in larger data sets could provide more reliable results. The author mentions a noticeable decline in their performance towards the end of a test, attributing it to mental fatigue. Additionally, they note multitasking during the test, specifically switching to Hacker News while waiting.
Top 2 Comment Summary
The article discusses a test that can be enjoyable but advises against taking it too frequently. The author mentions that after several attempts, they found they could quickly process the shapes, filling, and positions, leading to improved timing.
8. Show HN: I built a Iridium/LTE satellite GPS tracker and took it to the Arctic
Total comment counts : 12
Summary
The article discusses the development of a custom GPS tracker that transmits data over both LTE and Iridium networks. This project was tested on the expedition yacht S/Y Southern Star during a journey from Norway to Svalbard in the Arctic. The tracker utilizes components like RockBLOCK 9603N for Iridium communication, SIMCOM7600G for LTE, and an STM32 microcontroller with FreeRTOS to manage tasks.
The author, who frequently travels by motorcycle and 4x4 into remote areas, aims to create a device that allows for navigation and communication in places lacking mobile coverage. The device records journeys and converts them into GPX format for sharing. The firmware was written in C, utilizing libraries for real-time processing and GPS data parsing.
The device features a GNSS NEO 8M module for location tracking, with satellite connectivity confirmation using the Iridium module. The LTE functionality was chosen over GSM due to better coverage experienced during preliminary tests. The tracker includes a display and is powered by a step-down converter, allowing it to operate across various voltage inputs. Although the code is acknowledged to have flaws, the project serves as a hobbyist endeavor driven by the author’s interest in electronics and exploration.
Top 1 Comment Summary
The author discusses a project at their company involving the development of a satellite/cell GPS tracker for civil aviation that uses similar GPS and Iridium modules as another project. They mention the high costs associated with satellite SBD messages, particularly as their device transmits position data every two minutes. While considering alternative providers, they find that Iridium remains the most suitable option despite the costs.
Top 2 Comment Summary
The article discusses the costs associated with a RockBoard satellite transceiver, which includes a hardware price of $302, a monthly line fee of $17, and a charge of $0.20 per message (up to 50 characters). The author expresses a desire for a more affordable and programmable Iridium device.
9. Diode Matrix
Total comment counts : 10
Summary
The article discusses the diode matrix, an early form of read-only memory (ROM) used in computers from the 1950s to the 1970s, prior to the invention of EEPROMs. Each bit in this ROM is indicated by the presence or absence of a diode, and it can be modified using simple tools like a soldering iron and wire cutters. The specific example provided is a floppy disk boot ROM for the PDP-11, consisting of 32 16-bit words. The article lists a series of machine code instructions stored on this board, detailing functions like clearing registers, moving data, branching based on conditions, and arithmetic operations. The instructions illustrate how the ROM operates within the context of the PDP-11 computer architecture.
Top 1 Comment Summary
The author shares a recent experience where a discussion on Hacker News about the early days of programming led to a mention of the modifiability of games like PONG, due to their use of diode matrices. Interestingly, soon after, the term “diode matrix” appeared prominently on the site.
Top 2 Comment Summary
The article explains why opcodes for the PDP-11 computer system are represented in octal rather than hexadecimal. It notes that although hexadecimal notation (0-F) was introduced in 1966, the PDP-11 was launched in 1970, indicating that octal may have been more familiar or practical at that time.
10. Waverley, the last seagoing paddle steamer
Total comment counts : 10
Summary
The article is structured like a blog with numerous links and features. It includes navigational elements for accessing older posts, main pages, and various social media links. The content seems to focus on London, its neighborhoods, and activities, highlighted by a curated list of blogs and interesting features about the city, such as museums, local history, and popular walking routes. The archive section shows a timeline of posts from previous years, indicating a long-running blog with diverse topics centered on London. Overall, it serves as a resource for exploring London, its culture, and its history.
Top 1 Comment Summary
The article describes the author’s experiences living near the Firth of Clyde, where the Waverley paddle steamer passes by their home twice daily during the summer. The Waverley is noted for its beautiful restoration and the opportunity for visitors to see its traditional piston engine and paddles in action, sparking interest in engineering among local children. The author finds it impressive to see the Waverley speed past submarines and highlights its speed, noting it outpaces cross-Clyde ferries. Additionally, the Waverley operates a short autumn season in London, providing scenic trips under Tower Bridge to Southend and nearby wind farms.
Top 2 Comment Summary
The article expresses a fondness for the paddle steamers operating on Lake Zurich. It highlights the captivating experience of observing the shining brass and chrome engine in the boat’s center, which draws attention away from the picturesque scenery outside. A YouTube link is also provided for further viewing.