Pretty sure 3rd party font blocking doesn't work

[sheerun]

Prerequisites

• This is not a support issue or a question
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue
• I am running the latest version of uBlock Origin

I tried to reproduce the issue when...

• uBO is the only extension
• uBO with default lists/settings
• using a new, unmodified browser profile

URL(s) where the issue occurs

https://www.logitech.com/pl-pl/products/mice.html

Describe the issue

If I add *$font,third-party then if I open Network tab of Developer Tools, I see that all first-party fonts are blocked, for example: https://www.logitech.com/asset/fonts/lineto-brown-pro-bold.woff.

Screenshot(s)

uBlock Origin version

1.44.2

Browser name and version

Firefox 104.0.2

Settings

Add *$font,third-party to My Filters

Notes

No response

[mapx-]

It's about cname
https://www.reddit.com/r/uBlockOrigin/comments/f8qnpc/ublock_origin_1250_with_cname_uncloaking_is_out/

For example the first-party
https://www.logitech.com/etc.clientlibs/logitech/clientlibs/replatform/resources/fonts/logi-icon-2.woff2

is uncloaked as third party https://d1hy6rfccmvxt8.cloudfront.net/ which your third-party filter will block and so in the Network tab you'll see uBO is blocking ... first-party (which instead is third-party)

You can open the logger and see the cnames

[mapx-]

if you add (nullifying the cname operation)
@@||logitech.com^$cname

You'll get a "clean" network tab

[sheerun]

Is there a way to universally block 3rd party cookies fonts? i.e. without something like logitech.com in rules

[sheerun]

Could I both have uncloaking enabled and prevent 3rd party fonts from loading, without website-specific filters? I want both and I think most people would like it this way :)

[gorhill]

prevent 3rd party fonts from loading

d1hy6rfccmvxt8.cloudfront.net is 3rd-party, uBO merely made this information visible, so the behavior you want occurred. It's the webmaster who decided to make those 3rd-party fonts appear as 1st-party, so if your argument is that the webmaster should get to decide what is getting blocked by uBO, this goes against your wish to block 3rd-party fonts.

[sheerun]

But html website www.logitech.com is itself cnamed to d1hy6rfccmvxt8.cloudfront.net, so any fonts loaded from d1hy6rfccmvxt8.cloudfront.net should be considered first party? In other words anything loaded from d1hy6rfccmvxt8.cloudfront.net should be considered 1st party, not only fonts

[sheerun]

Additional note: I get this issue on most websites, as most websites use CDN and static hosting for their primary domain. I guess the issue should say that 3rd party font blocking works too well :)

[gorhill]

But html website www.logitech.com is itself cnamed to d1hy6rfccmvxt8.cloudfront.net

Ok I see, then it's uBlockOrigin/uBlock-issues#1062, I still need to work on this.