Tachy0n is a permanent, unpatchable jailbreak for all bootroms from checkm8-vulnerable devices (A5-A11 on iOS 14.x). Leveraging a hardware vulnerability, it modifies the Secure Enclave Processor (SEP) firmware, enabling persistent code execution even after updates or restores. This effectively removes Apple's ability to revoke the jailbreak through software updates. While powerful, Tachy0n is primarily a research project and a proof-of-concept, currently lacking the user-friendly tools of a typical jailbreak. It aims to lay the groundwork for future jailbreaks and serve as a secure platform for experimentation and research on Apple's security systems.
"Notes" is an iOS app designed to help musicians improve their sight-reading skills. Available on the App Store for 10 years, the app presents users with randomly generated musical notation, covering a range of clefs, key signatures, and rhythms. Users can customize the difficulty level, focusing on specific areas for improvement. The app provides instant feedback on accuracy and tracks progress over time, helping musicians develop their ability to quickly and accurately interpret and play music.
HN users discussed the app's longevity and the developer's persistence, praising the 10-year milestone. Some shared their personal sight-reading practice methods, including using apps like Functional Ear Trainer and various websites. A few users suggested potential improvements for the app, such as adding support for other instruments beyond piano and offering more customization options like adjustable clefs. Others questioned the efficacy of pure note-reading practice without rhythmic context. The overall sentiment was positive, acknowledging the app's niche and the developer's commitment.
iOS 18 introduces a new feature that automatically reboots devices after a prolonged period of inactivity. Reverse engineering revealed this is managed by the SpringBoard process, which monitors user interaction and triggers a reboot after approximately 72 hours of inactivity. The reboot is signaled by setting a specific flag in a system property and is considered a "soft" reboot, likely to maintain device state where possible. This feature seems primarily targeted at corporate devices enrolled in Mobile Device Management (MDM) systems, as a way to clear temporary states and potentially address performance issues resulting from prolonged uptime without requiring manual intervention. The exact conditions for triggering the reboot, beyond inactivity time, are still being investigated.
Hacker News users discussed the potential reasons behind iOS 18's automatic reboot after extended inactivity, with some speculating it's related to memory management, specifically clearing caches or resetting background processes. Others suggested it could be a security measure to mitigate potential exploits or simply a bug. A few commenters expressed concern about the reboot happening without warning, potentially interrupting ongoing tasks or data syncing. Some highlighted the lack of official documentation on this behavior and the author's reverse engineering efforts to uncover the cause. The discussion also touched on similar behavior observed in other operating systems and the overall complexity of modern OS architectures.
Summary of Comments ( 36 )
https://news.ycombinator.com/item?id=44083388
Hacker News users discuss the Tachy0n jailbreak, expressing skepticism about its "last 0day" claim, noting that future iOS versions will likely patch the exploit. Some debate the practicality of the jailbreak given its limited scope to older devices and the availability of checkm8 for similar models. Others commend the technical achievement and the author's clear explanation of the exploit. Concerns about the potential for misuse of the exploit are also raised, alongside discussions about the ethics of disclosing such vulnerabilities. Several commenters point out the limitations of patching bootROM exploits, suggesting this won't be the truly "last" 0day. There's also interest in the potential for using the exploit for purposes other than jailbreaking, like device repair. Finally, a few users share personal anecdotes about jailbreaking and express nostalgia for the practice's heyday.
The Hacker News post titled "Tachy0n: The Last 0day Jailbreak" generated a significant amount of discussion, with many commenters expressing a mix of nostalgia, technical curiosity, and concern.
Several commenters reminisced about the "golden age" of jailbreaking, recalling the excitement and sense of community that surrounded it. They discussed the various tools and exploits used in the past, comparing them to Tachy0n and highlighting the evolution of jailbreaking techniques. Some expressed sadness that this might be one of the last opportunities for this kind of exploit due to increasing security measures implemented by Apple.
A recurring theme in the comments was the technical discussion of the exploit itself. Commenters inquired about the specifics of the vulnerability, how it was discovered, and the implications for future iOS security. Some debated the ethics of jailbreaking and the potential security risks associated with it. There was also discussion around the difficulty of finding and utilizing such vulnerabilities in modern iOS versions.
Some users expressed concern about the potential misuse of the exploit. They worried that the availability of such tools could lead to increased malware and security breaches. Others countered this argument, stating that jailbreaking primarily empowers users to customize their devices and bypass restrictions imposed by Apple.
A few comments focused on the practical aspects of jailbreaking. Users asked questions about compatibility with different iOS versions and devices, the process of installing the jailbreak, and the availability of tweaks and modifications. Some shared their personal experiences with jailbreaking and offered advice to newcomers.
Several commenters also discussed the cat-and-mouse game between Apple and the jailbreaking community, noting that Apple often patches vulnerabilities quickly after they are discovered. This led to discussions about the future of jailbreaking and the likelihood of similar exploits being found in the future.
Finally, there was some discussion about the name "Tachy0n" itself, with users speculating about its meaning and significance in relation to the exploit.
Overall, the comments on the Hacker News post reflect the complex and multifaceted nature of the jailbreaking community, highlighting the technical skills, ethical considerations, and nostalgic sentiment associated with this practice.