cannot login with Firefox and privacy.firstparty.isolate=true

[Ivano Luberti]

As stated in the object I cannot login with

Firefox and privacy.firstparty.isolate=true in about:config (default is false)

Atlassian complains that Firefox doesnt' accept third parties cookie but that is not true

[Ben Finney]

"To get around this"

Thank you for identifying that Atlassian's cross-site linkage is the cause of this problem.

As you've described it, this is a security problem. The solution is for Atlassion to fix this security vulnerability: ensure that the Atlassian login process does not require cross-site linkage of the kind explicitly prevented by First Party Isolation.

[somethingblue]

Hi Ivano,

I was able to replicate the same behavior by editing that key.  I believe the issue is not with Firefox as you can see it works if privacy.firstparty.isolate=false.

This setting is most likely the culprit as it does affect third party cookies as you can see from the following description about the purpose of First Party Isolation:

First Party Isolation, also known as Cross-Origin Identifier Unlinkability is a concept from the Tor Browser. The idea is to key every source of browser identification with the domain in the URL bar (the first party). This makes all access to identifiers distinct between usage in the website itself and through third-party. Think of it as blocking Third-party cookies, but more exhaustively. Here are Firefox's implementation details about First Party Isolation.

This is also explained in another article titled How to enable First-Party Isolation in Firefox:

The feature restricts cookies, cache and other data access to the domain level so that only the domain that dropped the cookie or file on the user system can access it.

This is a stark contrast to how cookies work normally, as marketing companies tend to drop cookies with their ads on sites, so that they may track users across all properties that the ads or scripts run on.

With First-Party Isolation enabled, tracking ends at the domain level which means that advertisers cannot use cookies anymore to create user profiles by dropping and reading cookies across the Internet.

The following items are affected by First-Party Isolation: cookies, cache, HTTP Authentication, DOM Storage, Flash cookies, SSL and TLS session resumption, Shared Workers, blob URIs, SPDY and HTTP/2, automated cross-origin redirects, window.name, auto-form fill, HSTS and HPKP supercookies, broadcast channels, OCSP, favicons, mediasource URIs and Mediastream, speculative and prefetched connections. 

To get around this please disable First Party isolation.

Cheers,

Branden

[Edgaras Šeputis]

Alternatively you could make it work without making browser less secure/less private...

[Ben Finney]

"To get around this"

Thank you for identifying that Atlassian's cross-site linkage is the cause of this problem.

As you've described it, this is a security problem. The solution is for Atlassian to correct this security vulnerability: ensure that the Atlassian login process does not require cross-site linkage of the kind explicitly prevented by First Party Isolation.

[OJFord]

Is this going to be fixed?

[Niels Pedersen]

I'm facing this issue at the moment. I can confirm that turning off first party isolation will fix the "issue". Any news on fixing this?

[Pablo Cholaky]

That's definitively a bad fix, as is promoting users to allow websites to read "shared" third party cookies.

This is a 2+ years security issue, and still reproducible. Hope it get fixed this year, as no company would like expose their users to any kind identity attacks.

Most corporate websites don't have any problem with cookie isolation.

Thanks.