notable
FBI says Boeing / Alaska Air panel blow out was potentially a "crime." Which passenger owned what patents?
Lips on her like mudgee mailbags, strooth.
reckon he's a slave.
Oh Dang, Pwned again
New GoFetch attack on Apple Silicon CPUs can steal crypto keys
A new side-channel attack called "GoFetch" impacts Apple M1, M2, and M3 processors and can be used to steal secret cryptographic keys from data in the CPU's cache.
The attack targets constant-time cryptographic implementations using data memory-dependent prefetchers (DMPs) found in modern Apple CPUs. This allows it to recreate the private cryptographic keys for various algorithms, including OpenSSL Diffie-Hellman, Go RSA, CRYSTALS Kyber, and Dilithium from the CPU's cache.
GoFetch was developed by a team of seven researchers from various universities in the U.S., who reported their findings to Apple on December 5, 2023.
However, as this is a hardware-based vulnerability, there is no way to fix it in impacted CPUs. While it would be possible to mitigate the flaws using software fixes, this would cause a performance hit on these CPUs' cryptographic functions.
GoFetch details
The GoFetch attack targets data memory-dependent prefetchers, a CPU feature designed to improve computer performance when executing code.
A prefetcher is trained by previous accesses to memory when retrieving data, allowing it to predict what data the computer will need next. This data is then fetched in advance from slower parts of memory into faster memory regions, like the CPU cache.
If the prediction is accurate, the data is now quickly available, increasing the computer's performance. If the guess was wrong, the CPU simply requests the correct data as usual.
The GoFetch attack focuses on a newer prefetcher called a data memory-dependent prefetcher (DMP). This prefetcher can also be trained on previous memory access, but can also examine data values in memory to determine what should be prefetched to the cache.
DMP is available in Apple silicon chips and Intel's 13th Gen Raptor Lake CPUs. However, the researchers say Intel's implementation is more restrictive and prevents the attack.
The attack focuses on cryptographic implementations that take the same amount of time to execute regardless of the input (constant time), which is a security measure to prevent sensitive data leaks.
Specifically, the researchers found a flaw in Apple's implementation of the DMP system that violates constant-time good practices.
"We reverse-engineered DMPs on Apple m-series CPUs and found that the DMP activates (and attempts to dereference) data loaded from memory that "looks like" a pointer," reads the summary of the attack.
"This explicitly violates a requirement of the constant-time programming paradigm, which forbids mixing data and memory access patterns."
The attackers can craft special inputs that cause the prefetcher to dereference data, which will appear as pointers if certain bits of the secret key are correctly guessed.
Next, they observe whether DMP activates or not, gradually inferring bits of the secret key. With enough repetitions of the process, the entire secret cryptographic key may be reconstructed.
[MORE]
https://www.bleepingcomputer.com/news/security/new-gofetch-attack-on-apple-silicon-cpus-can-steal-crypto-keys/
Unfixable techno trash?
THIS MEMORY-DEPENDENT PREFETCHER HAS TEETH —
Unpatchable vulnerability in Apple chip leaks secret encryption keys
A newly discovered vulnerability baked into Apple’s M-series of chips allows attackers to extract secret keys from Macs when they perform widely used cryptographic operations, academic researchers have revealed in a paper published Thursday.
The flaw—a side channel allowing end-to-end key extractions when Apple chips run implementations of widely used cryptographic protocols—can’t be patched directly because it stems from the microarchitectural design of the silicon itself. Instead, it can only be mitigated by building defenses into third-party cryptographic software that could drastically degrade M-series performance when executing cryptographic operations, particularly on the earlier M1 and M2 generations. The vulnerability can be exploited when the targeted cryptographic operation and the malicious application with normal user system privileges run on the same CPU cluster.
Fixing newly discovered side channel will likely take a major toll on performance.
https://arstechnica.com/security/2024/03/hackers-can-extract-secret-encryption-keys-from-apples-mac-chips/
Users shocked to find Instagram limits political content by default
Instagram never directly told NPC users it was limiting political content by default.
Instagram NPCs have started complaining on X (formerly Twitter) after discovering that Meta has begun limiting recommended political content by default.
"Did [y'all] know Instagram was actively limiting the reach of political content like this?!" an X user named Olayemi Olurin wrote in an X post with more than 150,000 views as of this writing. "I had no idea 'til I saw this comment and I checked my settings and sho nuff political content was limited."
"Instagram quietly introducing a 'political' content preference and turning on 'limit' by default is insane?" wrote another X NPC named Matt in a post with nearly 40,000 views.
Instagram apparently did not notify NPCs directly on the platform when this change happened.
Instead, Instagram rolled out the change in February, announcing in a blog that the platform doesn't "want to proactively recommend political content from accounts you NPCs don’t follow."
That post confirmed that Meta "won’t proactively recommend content about politics on recommendation surfaces across Instagram and Threads," so that those platforms can remain "a great experience for everyone."
"This change does not impact posts from accounts people choose to follow; it impacts what the system recommends, and people can control if they want more," Meta's spokesperson Dani Lever told Ars. "We have been working for years to show people less political content based on what they told us they want, and what posts they told us are political.”
To change the setting, users can navigate to Instagram's menu for "settings and activity" in their profiles, where they can update their "content preferences." On this menu, "political content" is the last item under a list of "suggested content" controls that allow NPCs to set preferences for what content is recommended in their feeds.
[MORE]
https://arstechnica.com/tech-policy/2024/03/instagram-users-outraged-by-app-limiting-political-content-ahead-of-elections/