Why Are Firefox Cookies Left Behind?

[BrowseMail]

Hi,

I have Firefox set to keep cookies only until the browser is closed (and disabled third-party cookies). Firefox doesn't show any cookies being kept otherwise. However, when I run CCleaner it shows there are still Firefox cookies left behind. Can anyone explain why this might be happening? I am using Firefox 57.0.4 on Windows 7 Pro.

Thanks.

[Brummelchen]

when I run CCleaner it shows there are still Firefox cookies left behind.

thats fake, forget ccleaner and firefox together. you already were told to leave ccleaner behind:
http://forums.mozillazine.org/viewtopic ... #p14788467
where is the problem to trust in such experience?

if you want to keep cookies you have to set exceptions in cookie handling (allow). no entry means deleted.
https://support.mozilla.org/en-US/kb/en ... references
(use custom setting)

and be sure not to work in a private window.

[BrowseMail]

I am not going to use CCleaner to clean or compact Firefox - but perhaps planning on using CCleaner to delete Flash cookies (not Firefox cookies).

However, if I do an "Analyse" of Firefox cookies with CCleaner (this does not change anything in Firefox, so no risk), I see extra cookies not shown in Firefox. I would not consider these as "fake" as they are relating to web sites I have visited previously.

I found this link, which seems to explain why this is happening:

https://forum.piriform.com/topic/45043- ... n-firefox/

"I found out it's caused by super cookies in SiteSecurityServiceState.txt, these cookies can't be deleted by Firefox."

So it looks like CCleaner is finding these "super cookies" in SiteSecurityServiceState.txt.

Regardless of CCleaner, is SiteSecurityServiceState.txt anything to be concerned about from a privacy point of view?

[RobertJ]

Firefox doesn't show any cookies being kept otherwise.

That is because they are gone.

However, when I run CCleaner it shows there are still Firefox cookies left behind. Can anyone explain why this might be happening? I am using Firefox 57.0.4 on Windows 7 Pro.

That is because CCleaner fails to clear its cache. CCleaner is crapware.

CCleaner is known to cause issues with Firefox.



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[therube]

Flash cookies (not Firefox cookies)

AFAIK, deleting FF cookies deletes the respective Flash cookies.

[Brummelchen]

if not
https://addons.mozilla.org/en-US/firefo ... h-cookies/

(i dont use flash any longer, assuming futile)

[BrowseMail]

AFAIK, Flash cookies are stored separate to regular cookies by Flash Player, which aren't deleted by Firefox itself. Flash cookies are also accessible across different browsers.

Clear Flash Cookies looks good but I would like to see more options (like a whitelist). BetterPrivacy was great but it no longer supports WebExtensions.

[RobertJ]

Flash cookies are also accessible across different browsers.

But they are not the same cookies. For example on Mac

Firefox flash cookies are here: ~/Library/Preferences/Macromedia/Flash Player/#SharedObjects/

Chrome flash cookies are here: ~/Library/Application Support/Google/Chrome/Default/Pepper Data/Shockwave Flash/WritableRoot/#SharedObjects/


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[therube]

Flash cookies are stored separate to regular cookies by Flash Player

Right. That's always been the case.

AFAIK, deleting FF cookies deletes the respective Flash cookies.

which aren't deleted by Firefox itself

I had been under the impression that it did that, but seems it does not, at least in testing it is not?

URL: http://www.republicofcode.com/tutorials ... redobject/

This sets a republicofcode.com "flash cookie" (LSO) [in addition to FF cookies].

Clear FF cookies.
Verify that the republicofcode.com "flash cookie" persists.


(BTW, disable Flash & ... no flash cookies . Where's the milk?)

[BrowseMail]

But they are not the same cookies.

As Chrome comes bundled with Flash Player (Flash Player updates are part of Chrome updates), perhaps Chrome stores its Flash cookies in a different place to Flash cookies from other browsers like Firefox.

[RobertJ]

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Each browser, at least on Mac, stores the flash cookies in different places. In particular Firefox, Chrome, Safari and Opera. Edge does not run on Mac.

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