Firefox comes with a built-in password handler tool that recalls usernames and passwords for all the websites you visit. This login/password data is stashed away in the encrypted form in Firefox database files residing in the user’s profile directory.
However, anyone can simply launch the password manager from the Firefox browser and see the credentials. Also, one can simply copy these database files to another machine and view them offline utilizing the tools such as FirePassword.
Hence to protect from such threats, Firefox uses master passwords to provide enhanced security. By default, Firefox does not set the master password. However once you have set the master password, you need to provide it every time to view login credentials. So if you lose the master password then that means you have lost all the stored passwords as well.
So far there was no way to recover these credentials once you have lost the master password. Now the FireMasterCracker by Securityxploded can help you to recover the master password and get back all the sign-on information.