Bug/Proposed feature: Enable command-line access to be password-restricted

[Perspectoff]

I use both Grub Legacy and Grub2 on many computers ((K)Ubuntu, OpenSuse,
Debian, multiple versions of each).

I can not find a way to password-restrict access to the Grub command
line in either version.

This allows a passerby to enter "c" to invoke the command-line and then
enter commands manually to boot an external device, circumventing BIOS
restrictions.

Password restricting/locking menu items and removing recovery mode menu
items (through the configuration settings) does not impact command-line
access, which remains unrestricted.