It's a tricky situation. In first version of Firefox sync the password was saved locally (probably in chrome://FirefoxAccounts address). In the next version it was encrypted and I do not know how to get the password from there. But I was lucky to recover my password from https://accounts.firefox.com page, because I saved it intentionally there. In password manager you can save from this https://accounts.firefox.com/signin page. If it does not save the password then before loging in use bookmarklet for allowing save passwords in forms https://www.squarefree.com/bookmarklets/forms.html Otherwise You can restore password from here https://accounts.firefox.com/reset_password but will loose data that is saved there.