I’ve just been playing around with https://browserleaks.com/fonts . It seems no web browser provides adequate protection for this method of fingerprinting – in both brave and librewolf the tool detects rather unique fonts that I have installed on my system, such as “IBM Plex” and “UD Digi Kyokasho” – almost certainly a unique fingerprint. Tor browser does slightly better as it does not divulge these “weird” fonts. However, it still reveals that the google Noto fonts are installed, which is by far not universal – on a different machine, where no Noto fonts are installed, the tool does not report them.

For extra context: I’ve tested under Linux with native tor browser and flatpak’d Brave and Librewolf.

What can we do to protect ourselves from this method of fingerprinting? And why are all of these privacy-focused browsers vulnerable to it? Is work being done to mitigate this?

    • NaibofTabrEnglish
      7•5 months ago

      Flatpak is not a container and should not be thought of as such for security/privacy purposes:

      In general though we try to avoid using the term container when speaking about Flatpak as it tends to cause comparisons with Docker and rkt, comparisons which quickly stop making technical sense due to the very different problem spaces these technologies try to address. And thus we prefer using the term sandboxing.

      https://flatpak.org/faq/#Is_Flatpak_a_container_technology_

      It can provide container-like functions if specifically configured for that, but that’s not normal and it shouldn’t be relied on as a security barrier.

    • @[email protected]
      4•5 months ago

      I would not count on it, since it’s required for proper theme integration. A quick search confirms my suspicion: some font direcories are mapped.

      I quite like the idea though, sort of a lite qubes or unmodified VM for all Firefox Flatpak users could be nice.

    • @renzevOPEnglish
      1•5 months ago

      I’m running Brave and Librewolf from flatpak. Nope, it doesn’t help, at least with default sandbox settings.