Cloudflare Turnstile requiring fingerprintable WebGL (hacktivis.me)
199 points by HypnoticOcelot 3 hours ago
denysvitali 2 hours ago
Cloudflare is known to use fingerprinting to detect scrapers For example, they use JA3 fingerprints and match them against the UA to block stuff like cURL while allowing OkHttp (Android clients) - but this can be easily be spoofed with packages such as CycleTLS [1].
I don't want to defend them, because they gate away a good chunk of the internet with their "bot protection", but unless you do PoW (which is also ecologically a nightmare), probably fingerprinting is the way to go - completely destroying the privacy of everyone involved.
Cromite, a privacy conscious fork of Chromium for Android, has constantly issues with CloudFlare Turnstile [2] because they (Cloudflare) try to fingerprint it in multiple ways in order to pass the challenge. The only way to get it to work would be to join the CloudFlare Browser Developer program - which requires signing an NDA. Rightfully so, the project maintainer didn't want to do it.
If you want to see the extent of what CloudFlare does to fingerprint the browsers, just have a look in the issue [2] and see which flags need to be disabled in order to allow CloudFlare to pass the challenge.
I understand both sides, but at least CloudFlare could be flexible enough to fall back to PoW instead of just blocking people from sending forms or accessing websites...
jwr 29 minutes ago
> I don't want to defend them, because they gate away a good chunk of the internet with their "bot protection"
They also gate away a good many people with their "bot protection". I am extremely worried about how so many seem to have outsourced the control over who can access their websites to a company, with no second thoughts whatsoever.
denysvitali 10 minutes ago
They sometimes have to comply with legal requests (which I understand), but at the same time they have a huge market share - which means that the internet is becoming less and less decentralized and more in their control. We've seen the effects of that in previous outages...
b65e8bee43c2ed0 an hour ago
it's all for nothing, because Cloudflare's scraping protection works about as well as a $5 padlock - good enough to dissuade bored teens, not good enough to dissuade even an amateur burglar. if someone wants to scrap your publicly visible data, they will. there's nothing you can do.
ACCount37 an hour ago
At the same time: it sure works well enough to annoy anyone with a "bad ASN" IP with 80 captchas a day.
shideneyu an hour ago
petu 43 minutes ago
> but unless you do PoW (which is also ecologically a nightmare)
Can you expand? I don't see a problem with some napkin math. 5W load for 2 seconds is 0.002Wh (we have to let smartphones pass and not by doing PoW for 10s of seconds). 8 billion checks a day for a year = 8GWh.
denysvitali 13 minutes ago
I stand corrected. It's not a nightmare scenario (as for Bitcoins) - but I'm still of the idea that "useless" computations should be avoided (as we should avoid having 10MB websites).
In any case, according to some napkin math done by Kimi 2.6 (which by itself is probably already consuming more than all of my PoW challenges for the upcoming 5 years) - the situation looks incredibly in favor of PoW: https://www.kimi.com/share/19e7ef40-a432-8912-8000-0000b4a71...
Which makes me wonder why CloudFlare isn't switching to this already
dcrazy 5 minutes ago
PearlRiver 2 hours ago
This is why I have two separate browsers. If you want to do official stuff like paying for things you need to get through cloudflare.
notafox an hour ago
You can use Firefox with different profiles and configure it to launch particular profile directly, without launching default profile and using about:profiles.
Firefox with a non-default profile can be created like that:
./firefox -CreateProfile "profile-name /home/user/.mozilla/firefox/profile-dir/"
# For, say, cloudflare that would be:
./firefox -CreateProfile "cloudflare /home/user/.mozilla/firefox/cloudflare/"
./firefox -profile "/home/user/.mozilla/firefox/profile-dir/"
# For cloudflare that would be:
./firefox -profile "/home/user/.mozilla/firefox/cloudflare/"
- create a copy of it, say, /usr/bin/firefox-cloudflare
- adjust the relevant line, adding the -profile argument
Of course, "./firefox" from examples above should be replaced with the actual path to executable. For default installation of Firefox the path would be in /usr/bin/firefox script.
So, you can have a separate profiles for something sensitive/invasive (linkedin, cloudflare, shops, banks, etc.) and then you can have a separate profile for everything else.
And each profile can have its own set of extensions.
ferfumarma 22 minutes ago
helterskelter an hour ago
Firefox added profile switching recently. Works good.
(That said, I still keep separate machines. One for doing "official" things, the other for everything else)
notafox an hour ago
ajb an hour ago
b65e8bee43c2ed0 an hour ago
JoshTriplett 2 hours ago
"This makes your browser appear suspicious because it looks like you're trying to hide your identity."
Yeah, this needs to be burned to the ground.
gruez an hour ago
Bad optics aside, it doesn't actually reflect reality. See my other comment. You can enable basically all the privacy settings and still pass turnstile. Tor browser in a VM passes it, of all things.
JoshTriplett an hour ago
Any idea what the difference is between your setup and the one in the article that failed with fingerprint-resistance enabled?
gruez an hour ago
4oo4 an hour ago
I tested this extension that I've been using for a long time on the turnstile page and it got through, fwiw. I think it's a bit more subtle than how resistfingerprinting works but not sure what the privacy tradeoff is.
dblohm7 26 minutes ago
> Plus privacy.resistfingerprinting isn't enabled even when selecting "Strict" "Enhanced Privacy Protection" in the settings, great job there Mozilla.
That pref is there for the Tor Browser.
malka1986 2 hours ago
Thanks, i did not know about `privacy.resistfingerprinting`
I'll make sure to fail all cloudflare turnshit in the future.
gruez 2 hours ago
I have it enabled and turnstile works fine.
jeroenhd 4 minutes ago
It breaks Turnstile for me on Android. Had to restart the browser for it to take effect of course.
adamtaylor_13 2 hours ago
So if you need to prevent bot abuse, but also don't want an ugly captcha every time someone goes to sign up, is there a better option?
ribtoks 2 hours ago
Use proof-of-work captchas, many are private by default. Look into Private Captcha or Cap captcha.
phoronixrly an hour ago
How does proof of work stop bots?
stephantul an hour ago
ray_v an hour ago
ImPostingOnHN 2 hours ago
The tool "Anubis" uses proof of work instead
BetterThanSober an hour ago
With a tuned cool down period this isn't a problem, especially if you frequent the sites. OpenWRT uses Anubis and usually when I need to peruse their site I'm on a very low-end device. I prefer waiting much more over finding Waldos
But in principle I agree that there's no good answer to this, scraping _is_ useful and I bet most of us here had scraped something, it is AI company and their use of human's material for training without consent and return that led us to this (I know botting exists in forum since forum is a thing but it is easily solved by human moderators and keyword filter)
timpera 2 hours ago
Anubis often takes more than 60 seconds to complete on low-end devices (especially old smartphones). It seems like there's no good solution.
QuantumNomad_ an hour ago
dangus an hour ago
ImPostingOnHN 2 hours ago
phoronixrly an hour ago
How does Anubis stop bots?
xena an hour ago
avallach 2 hours ago
Doesn't this mean we just need to make the webgl fingerprint resistance implementation smarter? Instead of explicitly rejecting webgl access or responding with dummy data, respond with data that is random within space of N common and reproducible patterns. E.g. emulate webgl implementation of some low spec but actually popular devices.
bflesch an hour ago
All of those advanced features should be enabled on a per-website basis but unfortunately even browsers whose marketing focuses on privacy don't allow you to do that. Same with TLS root CA certificates, there is no way to configure that a certain CA can only create certificates for certain domains.
Dwedit an hour ago
Adding noise to a canvas element is a mistake anyway. It means you can't develop a proper paint program using web technologies because your browser will mess with the image.
tosti 14 minutes ago
You can still do that, but it may not be rendered correctly in a screenshot.
gruez 2 hours ago
This blog post is filled with false assumptions.
>Turns out it's because Cloudflare wants to have a fingerprint of your device via WebGL, the only reason for doing this would be tracking.
> So Cloudflare just banned all WebKitGTK browsers as I guess they put an exception for Safari.
This is false. I ran firefox with:
* hardware acceleration disabled (so software renderer, nothing to fingerprint)
* resistfingerprinting enabled, including letterboxing with default window size
* webgl disabled
* VPN enabled
* In a Windows VM
By all accounts this should be the most suspicious fingerprint ever, but turnstile happily lets me through. If they want to track people, they're doing a pretty bad job. My guess is that OP's browser is getting banned because his WebKitGTK has a weird fingerprint, not because of webgl or whatever.
> Such things are blocked in WebKit, and have been for years. Meaning it's tracking so awful that even Apple would block it, and as far as I can tell it's not the kind of privacy protection you can easily disable in it.
This is also false. Webgl fingerprinting works just fine on Safari. They might try to mitigate it by adding some noise, but that's not so different than what firefox does, and is certainly not "blocked".
jeroenhd 3 minutes ago
Enabling resistfingerprinting on my Android phone shows me the same error screen. It's not just webkit.
fingerprintingProtection works fine on the other hand, but then again that's intentionally less intrusive.
shiomiru 2 hours ago
> My guess is that OP's browser is getting banned because his WebKitGTK has a weird fingerprint, not because of webgl or whatever.
So why is Cloudflare saying the author got blocked because of WebGL?
> > Such things are blocked in WebKit, and have been for years. Meaning it's tracking so awful that even Apple would block it, and as far as I can tell it's not the kind of privacy protection you can easily disable in it.
> This is also false. Webgl fingerprinting works just fine on Safari. They might try to mitigate it by adding some noise, but that's not so different than what firefox does, and is certainly not "blocked".
While I don't have an iDevice to try, the assumption that they are special cased is fair... because they are: https://blog.cloudflare.com/eliminating-captchas-on-iphones-...
(Yes, this is basically WEI in a shinier package.)
gruez 2 hours ago
>So why is Cloudflare saying the author got blocked because of WebGL?
No idea. I can't even reproduce the error OP got with webgl disabled.
superkuh 2 hours ago
Yep. Cloudflare and cloudflare's customers don't care about blocking people that use non-standard browsers (or accessible browsers, or feed readers, or whatever). Using cloudflare defaults is basically saying, "Only major corporate browsers released in the last year or two can access this site."
kordlessagain an hour ago
I did warmups in Grub Crawler to fight this: https://deepbluedynamics.com/grub
nulledy 3 hours ago
As turnstile users on several of our sites, I think we need to revisit that decision.
sammy2255 2 hours ago
Out of curiosity, why did you have it on in the first place?
nulledy an hour ago
Bot rejection for contact forms. Better UX than reCaptcha.
Wowfunhappy 2 hours ago
...in the age of AI, does anyone have an actual solution for keeping out bots while preserving the privacy of humans?
Obviously this is terrible, but I think there's a possibility it's the least terrible option? Another option is IP reputation, which I think is worse. Or scanning a code with a non-rooted phone, which I think is even worse than that!
jeroenhd a minute ago
Remote attestation should still be possible with a rooted phone if phone manufacturers weren't so shit. If the attestation happens at hardware level, it doesn't matter what programs or kernels you're running.
fidotron 2 hours ago
> ...in the age of AI, does anyone have an actual solution for keeping out bots while preserving the privacy of humans?
There isn't one, and pretending otherwise is nonsense because humans will always provide their credentials to something to act on their behalf.
In the limit you end up with Chinese phone farms.
tardedmeme 2 hours ago
Right. Botnet operators love cloudflare because they make so much money renting out compromised machines to pass their tests.
thisislife2 2 hours ago
The only solution is regulation. If all content created by anyone has a copyright, how does an implicit opt-in (which is what happens if you don't create a robots.txt file for your website) for scraping make any sense? Moreover, even if you have a robots.txt, AI (or whatever) bots often don't respect it (or use workarounds - they outsource scraping of such "restricted" sites to unethical third-parties to get the data; Meta has even resorted to piracy, openly!). So clearly, the logic and the "honour system" has failed.
Cloudflare, Google Captcha, HCaptcha etc. are all shitty technical solutions because, as we are all discovering, it comes at the cost of our privacy (i.e. our personal data may monetise these services) and / or our computing resource and time. If current copyright laws aren't sufficient to prevent this, we have to acknowledge the system is broken. The answer could be enhancing it with some kind of Digital Millennium Copyright Act (DMCA) -like laws, but in favour of the creators against BigTech or rogue actors.
- Web-scraping and copyright law - https://www.neudata.co/blog/web-scraping-and-copyright-law
- Why DMCA Claims Against Web Scrapers Face Long Odds - https://capstonedc.com/insights/why-dmca-claims-against-web-...
oceanplexian an hour ago
Or you could let information be free, at least the stuff that’s on the public net.
As for issues like bots overloading websites or using too many resources scaling laws will take care of it quickly, it’s not like you can’t serve thousands of RPS from a Raspberry Pi these days.
ImPostingOnHN 2 hours ago
I don't think regulation will stop web scraping, not least of which because it can be done from locations outside the jurisdiction of the regulations.
> we have to acknowledge the system is broken
The system is broken. It probably takes, what, 10 seconds or less to use a residential or foreign proxy, 6+ months to internationally track and prosecute a single offender? So like a million times more effort going the regulatory route.
thisislife2 2 hours ago
cr125rider 2 hours ago
And identifying a bot that is acting on my behalf. Claude go search this topic is basically the same as Googling something and clicking on the results. Human driven AI searching needs to be in a different box than AI scraping for training data.
Which sounds extremely difficult to differentiate
JoshTriplett 2 hours ago
Hopefully it stays that way; "a bot acting on my behalf" is still a bot. At least it's often a well-behaved bot and uses a user-agent that can be detected and blocked.
Gander5739 2 hours ago
You don't need a non-rooted phone to pass captcha checks, I have a rooted phone and can pass the captchas that ask you to scan a qr code. But I doubt phones without google services would manage.
spacedoutman 2 hours ago
Private invite only internets
csomar 2 hours ago
They are not a problem unless you "believe" it is a problem. I estimate around 20-25K hits to my website from bots per day and I have all cloudflare protections disabled. Any decently optimized server should be able to easily handle that. (it's roughly 1 request every 3 seconds).
specialp 2 hours ago
Yes and that is just the bot background radiation of the internet. I run a primary source of information site and these botnets are aggressive to a DDOS level. All to do some sort of scraping. Because they have sophisticated enough tactics to DDOS us if they wanted to. However I am not sure their objective as they have wasted enough of our resources to have scraped all our content 1000s of times over. That 25k traffic is a couple of minutes for us. And that adds up. 80-90pct of our traffic is this
thisislife2 2 hours ago
True. But it still wastes your server resources, right? And it's sad that you have to accept that as part of the "cost" of hosting a site ...
ndriscoll an hour ago
doctorpangloss 2 hours ago
web environment integrity
malka1986 2 hours ago
> keeping out bot
You can forget about it. It is not possible. Simple as that.
Wowfunhappy 2 hours ago
Let's say I'm selling concert tickets. How do I prevent bots from buying up all the tickets and scalping them?
ranguna an hour ago
ndriscoll an hour ago
MyMemoryfails 2 hours ago
luckylion 2 hours ago
anonym29 2 hours ago
Say no to malware - say no to Cloudflare
bflesch an hour ago
Firefox has so much built-in tracking it seems they want to push me to build my own browser. For example every time you open the settings there are several ways they are sending out pings to certain extensions.
Also by default addons.mozilla.org is a privileged site so of course they include google tracking in it and they get the proper fingerprint no matter what you have configured.
shevy-java an hour ago
I wondered about that too. So they allege that bots require that everyone now has to ID to the big service providers. Very dystopian situation. Skynet is currently winning the war.
Fokamul 2 hours ago
Please, anyone from EU (US is doomed rofl) create a petition to ban browser-fingerprinting in EU, across all existing browsers.
I'm not good at creating petitions but can happily sign it. Also with stop killing games and anti-chat control.
I can imagine this can get a traction, if it's explained in youtube video to "normal" people.
fidotron 2 hours ago
A better solution would be to make webgl, webgpu and (especially) webrtc have some sort of prompt before they can be in any way used in that fashion, but this will absolutely destroy web ux Windows Vista style.
JoshTriplett an hour ago
And then the gatekeepers like Cloudflare will say "please hit accept in order to verify your browser and access this site".
richwater 2 hours ago
You mean the "Accept Cookies" banner that has become a complete joke? Pass
MyMemoryfails 2 hours ago
bflesch an hour ago
koolala 2 hours ago
a. Accept All
b. Accept Only Necessary Fingerprinting
kykat 2 hours ago
What? Big tech company is evil? No way! I thought cloudflare were good guys...
aleksandrm 2 hours ago
What gave you the impression that Cloudflare were the good guys?
tardedmeme 2 hours ago
Probably everyone on HN singing their praises for the past 10 years.
kykat 2 hours ago
aboardRat4 2 hours ago
Big tech companies are always visited first by the G-men who need something done.