Currently Firefox and other Mozilla products do not provide an easy way to export all root certificates. This extension adds an Export All button at the Authorities tab in Advanced→View Certificates, which allows to export all certificates at once.
Firefox and other Mozilla products currently allow to select all certificates and click to export. However, the user is asked to provide a filename for each root certificate. Considering that there are over 180 root certificates in Firefox, it becomes tedious to extract the certificates. In addition, several root certificates have the same common name (CN), therefore if you were to keep pressing Enter while exporting, you would end up overwriting them.