fingerprintjs / external-protocol-flooding

Scheme flooding vulnerability: how it works and why it is a threat to anonymous browsing
https://schemeflood.com
MIT License
644 stars 47 forks source link

False positives? #5

Open Forbo opened 3 years ago

Forbo commented 3 years ago

Each time I run the test, it returns a different set of applications and gives me a different identifier. The number of applications returned varies from 3-6, although it most often returns four applications. I don't have any of the applications that it says I do. Not sure how I'm defeating this, it could be any number of the privacy oriented extensions I'm currently using. I will see if I can narrow it down.

Edit: In subsequent runs, I have now seen it report anywhere from 1-6 applications. I observed this in Firefox 88.0.1 on Ubuntu 20.04.

spalt08 commented 3 years ago

Hey! Thanks for the feedback. Please provide information about your operating system and browsers you are testing.

Forbo commented 3 years ago

Sorry, I added that info after the fact in my edit. Quick response!

Forbo commented 3 years ago

Further testing with Chrome & Chromium yielded different results. Chromium said that I had all 24 applications installed. Chrome said I had 12 applications installed. However, Tor Browser appears to correctly detect that I have none of the applications installed, and does so consistently.

Oddly enough, Brave seems to be exhibiting the same behavior as Firefox, in that it returns a few results (3-6) that change each time. I figured the Chromium based browsers would all be pretty uniform in their results but it seems to be all over the place.

spalt08 commented 3 years ago

Honestly, I haven't tested it on Linux much.

However the default Ubuntu setup with default FF and Tor should work correctly. Any Chromium browser will not work, since it opens every application through xdg-open (shows the launch confirmation popup for every app)

Also, the accuracy can be low because of:

marvinborner commented 3 years ago

I've got similar problems: Firefox on Linux returns 24/24 positives for me although I have like 5/24 actually installed. It tries to open using xdg-open for every protocol (which is the case in Chrom{e,ium}), I guess.

System: Debian, FF 78.7.0 - both almost default setup.

Btw: I get a Firefox error popup (yellow bar at the top) with 'The clearkey plugin has crashed' at the end of the analysis.

spalt08 commented 3 years ago

If your Firefox opens applications via xdg-open - the demo will not work. You can test this by typing document.location = 'any-existing-scheme://' in the browser console.

I couldn't manage the demo to work this case.

marvinborner commented 3 years ago

Well, after a quick analysis this doesn't seem to be the case. My previous statement must be wrong then. The console returns Prevented navigation to “nordvpn://” due to an unknown protocol. (using nordvpn as an example as I don't have it installed). The schemeflood site does detect the presence of nordvpn though, which is weird.

Mte90 commented 3 years ago

I am getting a lot of false positive on Linux.

Screenshot_20210514_130307

I have just steam, telegram, discord and zoom. Also with another browser in the same pc the same detection.

andmagdo commented 3 years ago

I have a very custom firefox on linux and with the same browsing session, I have different fingerprints.

Edit: now detects correctly most of the time

ancipital commented 3 years ago

Another small data-point, an up-to-date Kali Linux's OOTB Firefox setup gives 23/24 apps installed for me- which is a pretty good false positive.

(Kali is easy to download as a usable VM image, if you want to test with it)

spalt08 commented 3 years ago

This might be affected by #10 I've just deployed the patch.

pachainti commented 3 years ago

Hi, I'm on GNU/linux and I'm getting a lot of false positive on both firefox and brave.

Forbo commented 3 years ago

I've done more testing since the patch in #10, I see fewer apps being detected on Firefox (typically only about 1-2). Those are still false positives, and still appear to be seemingly random in which ones it detects across multiple tests.

spalt08 commented 3 years ago

The result on Firefox may be affected by the config options in #14 as well

ghost commented 3 years ago

Tried today: image

mokanfar commented 3 years ago

Tried today:

I have the same identifier show up for me I have only 5 out of 24 apps displayed installed from same list as yours.

Browser: Version 92.0.4493.0 (Official Build) canary (64-bit) (Chrome)

OS: Windows 10 Pro Version 20H2 Installed on ‎3/‎19/‎2021 OS build 19042.985 Experience Windows Feature Experience Pack 120.2212.2020.0