> While the PoC demonstrates the JavaScript Spectre attack against Chrome 88's V8 JavaScript engine on an Intel Core i7-6500U 'Skylake' CPU on Linux, Google notes it can easily be tweaked for other CPUs... It was even successful on Apple's M1 Arm CPU...
And Augury [1] in 2022 also affected Apple's A14 and M1 chips.
So have Apple been attempting to mitigate and failing, or ignoring the issue?
Surely chip manufactures can't keep ignoring these fundamental flaws
[0] https://security.googleblog.com/2021/03/a-spectre-proof-of-c...
The reason this keeps coming up is that it isn’t a single issue but a class of attacks exploiting performance features, and attackers are getting more sophisticated as smart people figure out new techniques. Chip designers have been adjusting but are trying not to throw out the last couple decades of performance improvements, too.
I'm not sure, but after a bit more reading, it sounds like private-keys or symmetric-keys can be extracted from other user-space or possibly kernel-space code execution. And NOT from the secure enclave.
Just for what it's worth.
So for a) it might be sufficient to run javascript and for b) of course there are ways to inject data into server processes, processing data submitted by clients is what servers are for.
But a happens on clients (web browsers) and b would be a way to extract encryption keys from servers. But in what case can an attacker run code on a machine where they can also trigger the encryption (constantly for an hour like in the demonstration)? The only thing that comes to my mind would be a server side code-execution-sandbox that runs SSL termination on the same machine.
edit: Maybe stealing client certificate keys?
> The cryptographic key itself isn’t placed in cache. But bits of material derived from the key gets placed in the cache, and an attacker can piece these bits together in a way that allows them to reconstruct the key, after causing the processor to do this multiple times. The researchers were able to derive the key for four different cryptographic algorithms: Go, OpenSSL, CRYSTALS-Kyber and CRYSTALS-Dilithium.
> [Green] notes that in theory this attack might be used to break the TLS cryptography that a computer’s browser uses to encrypt communication between their computer and web sites, which could allow attackers to decrypt that communication to extract a user’s session cookie for their Gmail or other web-based email account and use it to log into the account as them.
This is probably worse given people were trying to experiment with local LLMs on CPU. Its not like they even offer Nvidia.
The mitigation for the issue was posted in coordination with the publishing of the vulnerability. Given that the mitigation only applies to the M3 processor, it's reasonable to assume that there is no currently known mitigation for the M1 and M2 processors.
Discussion on the actual vulnerability post: https://news.ycombinator.com/item?id=39779195
For example the vaporware Mill architecture is in-order on the CPU level but compilers can optimize to run code very concurrently.
There are a bunch of second hand cars below 6000 Singapore Dollars on this website[1], which is the price of the 64GB/1TB Mac Studio[2].
1 - https://www.sgcarmart.com/used_cars/listing.php?MOD=&PRC=18&...
Found this on the exploit site.
But it also says: "We observe that the DIT bit set on m3 CPUs effectively disables the DMP. This is not the case for the m1 and m2."
So if libraries set the DIT bit then M3 should be safe.
Are we nearing any sort of consensus that any form of speculation is bad? Is there a fundamentally secure way to do it?
Plus all the secrets in the Secure Enclave are immune to this attack, so your FileVault keys and your Apple Pay cards and all that jazz are completely safe.
It sucks that it exists, and crypto libraries that run on the platform outside of the Secure Enclave will get slightly slower, but no one will notice.
People said the _exact_ same thing about Spectre/Meltdown. Then the JS PoCs came out
What does this mean? All I read is access to user space. Wouldn’t any web browser be enough?
I may be misunderstanding what you intended but how do you use traditional means of payment (credit card) without an identity? How do you check your email without identity?
Please elaborate.
If I add a custom crypto extension to a RISC-V core and implement it badly, is that the fault of RISC-V? No! It's my own. And RISC-V doesn't help anyone here because their license allows me to keep my extension completely closed source - no different than Apple is today with ARM.
Complexity leads to bugs, some of which are going to be security bugs.
ISAs impose complexity upon implementations. To claim they do not matter would be disingenuous.
I think for "normal" users the main risk is JavaScript, which can (kind of) be mitigated in software without affecting the rest of the system, so no one really cares about these attacks. But the fundamental abstraction leak between physics and programming will always be there.
Examples (I'm running Debian)
The kernel, the X11 server, terminal, ssh, bash, anything coming from the official Debian repos including the password manager: in the trusted environment.
browsers, electron apps, anything installed from unofficial repos or language and package managers (npm, rvm, asdf, etc): in the untrusted environment.
It reminds me of mainframes and their redundant and compartmentalized hardware architecture.
The risk here is that there are more individuals with the skills to take this type of attack and bring it to a browser near you.
One apps data is another apps code.
At the hardware level any optimizations that change performance characteristics locally (how long the crypto operation directly takes) or non locally (in this case the secrets leak via observation of cache timings in the attacker's untrusted code) are unsafe.
Intel DMPs already have a flag to turn off the same behavior that was exploited on the M1/M2. Which may suggest that the risk of this type of optimization was understood previously.
Mixing crypto operations with general purpose computation and memory accesses is a fragile balance. Where possible try utilizing HSMs, yubikeys, secure enclaves - any specialized hardware that has been hardened to protect key material.
Are there any circumstances where this hardware is accessible in the browser? As I understand, it is not generally available (if at all) for any cryptography you might want to do in the browser.
Why only cryptographic applications? What if I'm writing a very sensitive e-mail, for instance?
The questions is what could be the solution going forward, which is going to be a huge change anyway. I do not see a way out of this with our current architectures.
Lets assume I multiply two 64bit numbers. The CPU could just do it the same way every time and the worst-case has 4 cycles latency. It may also track if one of the factors is zero and dynamically replace the multiplication with a zeroing idiom that "executes" in 0 cycles when the scheduler learns that that either input is zero as an extreme example.
Less radical it could track if the upper halves of registers are zero to fast-path smaller multiplications (e.g. 32bit x 32bit -> 64bit) and shave off a cycle. IIRC some PowerPC chips did that, but for the second argument only. The ISA allowed it.
A realistic example are CPUs with data-dependent latency shift/rotate instructions. What do you do if an ISA doesn't specify if shift/rotate is constant time, but every implementation of it so far did it in constant time? Do you slowly emulate it out of paranoia that a future implementation may have variable latency? An other real-world example of this would be FPUs that have higher latency for denormalised numbers its just not relevant to (most) cryptographic algorithms.
How the fuck are you supposed to build anything secure, useful, and fast enough from that?
EDIT: The downvotes make no sense. What this bug has in common with Spectre is that it has to do with cache timing. But in Spectre, the cache is affected by speculative execution; with "GoFetch", it's the pre-fetcher pre-fetching things which look like memory addresses. Pre-fetching is not speculative execution.
See the FAQ at https://gofetch.fail/
But if they did mean to include pre-fetching in "speculation" then I retract my comment
I’ve been using the TPM 2.0 chip on my ASUS based Linux box to store various keys. Tooling for this on the Linux side has improved significantly [0] and it’s been supported since kernel 3.20 (2015) [1].
How effective this is at improving one’s security posture is another question and it’s probably not a huge security upgrade, but it does mitigate some classes of attack.
I’m curious why you’re saying it’s explicitly not allowed? At least for standard TPM 1.2/2.0 chips, that isn’t the case.
- [0] https://wiki.archlinux.org/title/Trusted_Platform_Module
- [1] https://www.phoronix.com/news/Linux-3.20-TPM-2.0-Security
https://developer.apple.com/documentation/security/certifica...
https://developer.android.com/privacy-and-security/keystore#...
But I agree in general with your point
If people knew just how widespread and effective browser fingerprinting is they would be shocked. It's Cambridge Analytica on steroids.
The angle I’d worry about is something like a password manager, but most of those already have an authentication step and I’d be surprised if they didn’t have rate-limiting.
These vulnerabilities definitely exist, that much is a matter of fact. But whether it's something someone should consider in their threat model is a different matter.
One thing to remember here, though, is that there isn’t anything special about key material in this attack other than it being a high-value target. If we move all crypto to purpose-made hardware, someone could just start trying to target the messages to/from the crypto system.
This is one of the technical advantages of a blockchain-based system. As long as the keys are protected and signatures are generated in a secure environment, then the content of the message doesn't need to be secret to be secure.
It's not a solution to situations where privacy is desired, but if the reason for secrecy is simply to ensure that transactions are properly authorized (by avoiding the leakage of passwords and session information) then keeping the signature process secure should be sufficient even where general secrecy cannot be maintained.
> X11 server
Those can very easily execute untrusted code.
So it is $6,000 (car) + $100,000 (CoE)
Also why look at a mid tier upgrade spec when you’re looking at a bottom tier car?
Nah, my cheeky statement didn't talk specifically about new cars only. So it's only fair to look at second hand cars.
I was specifically talking about the most expensive Apple products vs the least expensive cars.
In contrast, the timing of virtually any email operation is not dependent on the contents of the email, other than the size. That is, whether you wrote "my password is hunter2" or "my password is passwor", the timing of any operation running on this email will be identical.
What about spell checkers etc? Or even just whatever runs to figure out where to break the lines?
Consider that those programs are not making any effort whatsoever to run in constant time, and yet no one has shown any timing attack against them. OpenSSL has taken great pains to have constant execution time, and yet subtle processor features like this still introduce enough time differences to recover the keys.
https://crypto.stanford.edu/~dabo/papers/ssl-timing.pdf
That's on the local network. I remember a paper doing this over the internet, but couldn't find it. A similar one over the internet:
https://www.usenix.org/conference/usenixsecurity20/presentat...
But in practice it's going to be malicious JS running in your browser: https://www.schneier.com/blog/archives/2021/03/exploiting-sp...
> The GoFetch attack is based on a CPU feature called data memory-dependent prefetcher (DMP), which is present in the latest Apple processors. 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. This explicitly violates a requirement of the constant-time programming paradigm, which forbids mixing data and memory access patterns.
> To exploit the DMP, we craft chosen inputs to cryptographic operations, in a way where pointer-like values only appear if we have correctly guessed some bits of the secret key. We verify these guesses by monitoring whether the DMP performs a dereference through cache-timing analysis. Once we make a correct guess, we proceed to guess the next batch of key bits. Using this approach, we show end-to-end key extraction attacks on popular constant-time implementations of classical (OpenSSL Diffie-Hellman Key Exchange, Go RSA decryption) and post-quantum cryptography (CRYSTALS-Kyber and CRYSTALS-Dilithium).
It sounds like the OpenSSL code is still constant time (it doesn't expect pointers in the intermediate values, to OpenSSL it is just data, not something it will ever dereference) but the attacker-controlled "monitoring" code's runtime changes based on whether the DMP ran or not.
If that's right, then the attacker still needs to run their monitoring code on the target, it isn't sufficient to just run OpenSSL etc itself.
Edit: it is more explicit in the paper, they assume that OpenSSL (the victim) is still constant time:
> In this paper we assume a typical microarchitectural attack scenario, where the victim and attacker have two different processes co-located on the same machine.
> For our cryptographic attacks, we assume the attacker runs unprivileged code and is able to interact with the victim via nominal software interfaces, triggering it to perform private key operations. Next, we assume that the victim is constant-time software that does not exhibit any (known) microarchitectural side-channel leakage. Finally, we assume that the attacker and the victim do not share memory, but that the attacker can monitor any microarchitectural side channels available to it, e.g., cache latency.
Unfortunately, I've had no luck getting others to buy into the idea that they should understand this level of detail so they can make these calls. Quite frustrating and depressing, since companies will relentlessly exploit their indifference.
If the only way to get trackers on the average person is to serve it from the same first-party domain, or to bundle it in with the giant 'app.js', you better believe they'll do that.
Right now, the fact that only a small fraction of people run adblockers, and an even smaller fraction block javascript, is what allows it to work.
In my case when every attempt fails I know it could be the side effect of some other privacy add on. If it's a random blog/news, that's the end of it. If I really have to use that site I open Chrome, do what I have to do, close it. Of course given a choice I pick sites that work well with only JS from a few inevitable sources.
I would like to salute my shitty ISP for keeping me safe from timing attacks using their unreliable network infrastructure.
That's plausible, but a very different argument from the original, that read:
> In contrast, the timing of virtually any email operation is not dependent on the contents of the email, other than the size.
From my perspective the original comment is not rocket science?
Maybe hackernews is mostly LLMs speaking at this point.
what a shame.
If you require someone to enter their credit card number every time they make a purchase they end up doing dumb, insecure things like storing it as a text file on their desktop.
And having external hardware just means more cables, batteries, updates to keep it secure etc.
Initiatives like PassKey, ApplePay, TouchID etc. have been a huge win for security and privacy.
this is merely the parent commenter's belief that they would should use different apps to reduce the risk vector when secrets are stolen.
no reason to completely ballistic.
I don't want to be forced into that model because I think it's too risky. I think YubiKeys and other devices which require physical device attachment to use to be too risky when I know other solutions exist (see a parallel comment, or below).
I want to teach my kids that if a phone is asking for permission, asking to verify id, asking to read complex terms of services, then you must be careful, and preferably not trust them. The current model is "identify yourself whenever the computer asks" and "click I Agree", which seems open to all sorts of abuse of power and trust.
How many people know they are giving up their rights to a trial in favor of forced arbitration? How many read the license which says to email 'law@example.com' to not waive that right? How many are able to understand the relevant issue? Effectively zero. Are high schools going to start teaching contract law so students are able to understand what they are expected to sign? No.
I also think switching to 2FA and passkeys empowers the Google and Apple duopoly. What happens if you lose your phone? How do you reestablish your passkeys?
"Simple. In your new phone, log back in to your Google or Apple account", right?
And if Google or Apple shuts down your account for some reason?
"Umm, make backups? Also have a YubiKey?"
That's a huge lock-in for the sort of people who would otherwise store their passwords in a cleartext file. At the very least everyone should be able to let their bank or other trust third-party store a copy of the end-to-end encrypted database, and that bank or third-party should have an enforceable legal obligation to store, maintain, and provide that encrypted database, and that new phones can restore from this database without needing Apple or Google authorization, after the person has physically visited the bank or police station and identified themselves sufficiently.
And if I say I want something more secure and more portable than a YubiKey to log in?
My bank login device has had one change of AAA batteries in about 7 years. It has had zero updates, because it is not programmable. It uses a camera to read something like a QR code, a screen to read the requested task, a number pad to enter a PIN, and I can read the response code on the screen, to enter into the computer. It can work with any device, even ones without available plugs.
(And my bank is legally responsible for ensuring the security level is enough, and updating if it is not. Apple is not. Google is not.)
While I love it for bank login (it's the orange one at https://www.sparbankenskane.se/privat/digitala-tjanster/sake... ) I also don't want that for all my services!
If I need to pull it out, I know that I'm doing something that requires extra attention and care. The rituals needed for different levels of authorization should be very different, to make it hard to get confused about what you are doing. I also have the ability to physically leave my higher authentication devices at home while I'm out for the day.
(UPDATE: acdha correctly pointed out the phishing attack possible in this approach. I do not know what the bank does to protect against phishing. But since this is a low-use service, which is unlikely to be targeted, and I am fastidious about double-checking, it seems like a low risk issue. Security through diversity.)
Why should I trust ApplePay's privacy more than I do my bank's? Is ApplePay required to follow the same Swedish privacy restrictions that my bank does? Is ApplyPay equally liable in case of errors? Can the Swedish government audit how ApplePay works and confirm it complies to the same level of privacy as my bank?
Every time I look into it, it seems the answers are always "no." Maybe it's changed?
Basically, I trust international companies who have abused their monopoly position with my security and privacy far less than I trust the Swedish government.
Different tasks require different levels of identification. Cash (a traditional means of payment) requires no identification. I only carry up to about $200 in cash on me, which an amount I'm willing to bear if my wallet is stolen.
When I use chip&pin ("what you have and what you know") for small payments, I rarely need any authentication, and when I do it's the PIN. My wife can and has used my card, with my permission. I have my email password written down for her so she can access it, eg, if I die and my computer dies.
The banking system probably factors in my usual payment locations to make the choice of when to ask for a PIN, combined with the trust experience with the vendor.
My card, even with a PIN, has a spending limit. Years ago I had to authorize raising the limit because my client was willing to reimburse me for a business class flight across the Atlantic. Of COURSE I want more friction in the system when doing something riskier. If the way to authorize a $60 dinner and a $60,000 car are too similar, then it's easier to fool you.
For a higher amount, I can go to the bank and carry out a transaction in person, or I can authorize it through their online banking system.
"But wait, how?" you might ask. The bank figured this out years ago, when people started going online, using unpatched Windows PCs without virus scanners.
The system - whose security I trust much more than a phone's - uses a small device with a camera. The login screen shows me a pattern with colored dots. The camera reads those dots, decodes the message (and probably also validates it cryptographically) and displays a message asking me to verify I want to log in.
I enter the PIN, and it generates a response code, which I enter.
If I make a payment, or add a new recipient, or a few other things, I am required to use the device again.
This device stays at home, because I don't expect to make $10,000 payments while out.
I can use it on any web-enabled device, because the security is in "what I have" and "what I know", in a device which cannot be hacked, does not require any physical connection, and does not require network accessed.
I like this system more than a Yubikey because it does not require a hardware attachment, which isn't always possible.
Yes, Yubikeys feel like a step backwards compare to my bank's security practice. I don't understand why there is no provision for cable-free/wifi-free/mobile-system-free validation in this supposed privacy-oriented switch to passkeys, when I know such a system exists.
Furthermore, the bank has the legal obligation to ensure the system works. If the encryption system is somehow broken, they are required to update the hardware. Apple is not. Yubi is not. The cost is all on you. My bank has even shut down mobile phone banking for older hardware/OSes, claiming the security isn't high enough. But they have not needed to update my security device.
If you expect your phone to be able to do anything, and authorize anything, then I see it as a giant risk. You can be at the bar, drank to much, and be convinced to make a payment or authorization that you shouldn't of. There's no real, physical way to change your risk level depending on the circumstances if you always have your phone with you.
Centralization of identify, payment, and apps is fundamentally flawed.
> I enter the PIN, and it generates a response code, which I enter.
How do they protect against phishing? That sounds like the weak MFA where attacks spoof the login page but make their own connection to your bank and pass through the challenge and response, which means that a user who doesn’t fastidiously check the hostname can be convinced to enter a TOTP, SMS, etc. code.
Phone-based WebAuthn systems are immune to that because they incorporate the hostname into the signing process so even if they convince you that they’re hugeb<cyrillic a>nk.com there’s no way for you to override that and give it a response which works for hugebank.com.
The same way they minimize the vulnerability when running on an exploited Windows machine?
Even if I log in, via a MITM attack, all they can do is read my account history.
Actually making changes requires further authorization. When I make a payment the screen asks me to confirm the amount I'm about to pay. The same applies to other security sensitive changes.
Still, you make a very valid point, and I thank you for pointing out the flaw in my understanding.
I still have a very deep distrust about centralizing identification, payment, and apps on a single device, and strongly dislike the inability to have physically very distinct trust levels.
Do they assume the OS is locked down and secure?
I mean, clearly if someone has a remote desktop view for my machine, then they can act as me, including any check for available hardware. The same should apply for a phone, yes?
If so, that sounds like my bank will never formally support running on a PinePhone or other user-inspectable/modifiable system - they will simply say they require a full chain of trust for the OS.
I'm glad the (relatively) open arenas of macOS and Windows existing, and that people have 10+-year-old machines, forcing my bank to support alternate login methods for less-trustworthy systems.
And majority of these would be secured via on device biometrics.
The fact that this is all happening with approval of credit card companies, banks, regulators etc means that the idea that centralisation is fundamentally flawed is simply wrong.
If there is a vulnerability, who pays for fixing it? Who pays for the new phones?
Of course the credit card companies and banks don't want to be responsible. They currently aren't, and they don't want to take it on.
Why should the regulators care yet? Using a mobile phone is still under the fiction that it's an optional functionality, where the user has agreed to take on the risk themselves, in exchange for better convenience and non-essential services.
If a single code gives access to everything, loosing that code to a malicious actors is really bad.
But I think you might overall be right that this requires two colocated processes: the paper talks about how the DMP breaks assumptions made by "the constant-time programming model", and I took this to mean that constant-time algorithms aren't constant-time any more. Reading more closely, I think maybe the issue is that "the constant-time programming model" was also assumed to make secrets safe from cache timing side-channels leaking the secrets to other processes on the same CPU, and this seems like it might be the assumption that's broken by the DMP...
I'll have to read more, I've just skimmed the abstract and introduction so far.
In any case, the stack of "this could not possibly be workable / but with enough statistics it can, and computers are plenty fast to generate statistically useful case numbers" is truly mindboggling with these attack vectors.
This also gets into e-waste issues. I really don't want multiple phones, and in any case, consumer phones are expected to be replaced every few years. A friend has an old iPhone which still works, but the local transit system's app no longer supports it. My bank's mobile app requires Android 7, etc.
That’s a good answer, too, especially of that custom message can be large enough to display the name & amount. Anything to jar people out of the “I thought I was sending $100 to the cable TV company, not $6,000 to someone in India” autopilot state.
I generally agree with your larger point and wish that banks would make it easier to do things like setup a Yubikey and require it be used on any transaction over a certain amount. I’ve never in my life needed to make a large transaction where I wouldn’t have been able to grab a token from my safe to approve it, and at some point delay becomes a security feature since it give the bank staff time to do things like call you and make sure you really intended to do something.
Certainly seeing articles like this about possible flaws in a centralized system, and the last of economic responsibility for fixing issues in affected customers, ... about people losing their Google id, the monopoly abuses of Google and Apple, and the e-waste issues of depending on apps which don't support old-but-working phones (sometimes in the name of security, but more often because it's expensive to maintain old phones) ... really gives me a bad feeling about this brave new world.