Any way to disable Option+Enter login?

[iRyan23]

I am wondering if there is a way to disable the Option+Enter method for a local admin to login to the active user’s session while the screen is locked.

[larry_barrett]

Try disable fast user switching and show input in login window. (go to system preferences -> Users -> Login Options . No idea what version of MacOS you're working with, but this works in Mojave and Catalina for sure.

I've actually had a situation where the opposite was true, where I could not use OPT+Enter to login.

[bvrooman]

I haven't tested this in Catalina yet, but we've been adding this line to /etc/pam.d/screensaver to mitigate:

account     required     tpam_group.so no_warn deny group=everyone ruser fail_safe

I wrote a quick script to append that line to the file, and that was effective.