iCloud: Untrust a saved Web browser I recently accessed iCloud Website using a device that I don't personally own and generally use.

After successfully logging-in by entering my Apple ID/Password and the Two Factor Authentication code, I was asked if I would like to trust the browser, so as to skip entering Two Factor Authentication code every time I login, I complied. (It isn't a public device and there is no possibility of unauthorized access)



This gave me the of flexibility to easily login in with just my Apple ID and password when I don't have any of my trusted Apple device around to get the Two Factor Authentication code.

Now, I am done using the device and will be returning it to the original owner. How do I untrust the Web browser?, i.e. require it to ask for Two Factor Authentication code next time a login is performed using my Apple ID? Also, is there a way to see a list of all similar trusted browsers and untrust them?
It appears that a cookie (probably X-APPLE-WEBAUTH-HSA-TRUST) is stored when you choose to trust the browser. Clearing cookies should essentially disable this functionality and require a 2FA code to log in again.

When you sign out of iCloud using the browser (Click your name in the top right corner and Sign Out), you are also presented with this dialog:



If you uncheck Remember me on this browser so I don't have to verify my identity next time. and sign out successfully, the browser will require a 2FA code the next time you log in.