Cookies aren't being cleared when Firefox is closed during a Windows restart
I have Firefox set to delete cookies on exit: 'Delete cookies and site data when Firefox is closed'. When I close Firefox manually then cookies are deleted as expected. However, when Firefox is closed by Windows, during a restart or shutdown, then the cookies are not deleted - when I start Firefox after the Windows restart I am already signed in to web sites that I was signed in to before the Windows restart.
I expect the cookies to be deleted for ANY close of Firefox - manual or automatic - this is what the option/setting name implies (to me). It's also the behaviour I want from a security perspective.
Is this what others expect?
The above is what happens when the setting 'toolkit.winRegisterApplicationRestart' is set to the default value 'true'. As a workaround I have had to set this value to 'false'. Is there a better way to get the behaviour I want (without having to manually close Firefox)?
Additional System Details
uBlock origin 1.21.2
- User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0
No, it only works when it is manually closed.
Hi basil.brush, the problem is caused by Firefox's crash recovery / session restore feature.
"Delete cookies and site data when Firefox is closed" checkbox changes the lifetime of cookies:
- Unchecked: lifetime is set to what websites request (default)
- Checked: lifetime is shortened to current session only
When Firefox is not closed normally, at the next startup, Firefox will perform a crash recovery and restore the previous session. That is how "session only" cookies can be reinstated.
If anyone has access to your computer, it would be safer to log out of sites. Otherwise, using the Restore Previous Session items on the menu might let an intruder back into sites left open the last time you exited Firefox.
Note that Firefox will never be able to clear the cookies with a forced shutdown, either via the Windows Task Manager or by closing down Windows. Clearing cookies when Firefox is closed is only possible if you close Firefox properly before closing down Windows.
You can possibly use a New Private Window to prevent Firefox from storing session data in the profile folder.