Red Hat Bugzilla – Bug 7875
no root passwd prompt when booting single user mode: linux single
Last modified: 2008-05-01 11:37:53 EDT
I had to boot single user mode today and realized I am not prompted for a
password. This is a really bad security risk.
Makes the system extremely vulnerable.
To duplicate: at the lilo prompt type: linux single
I tested this on RedHat 6.1 and Mandrake 6.1 which both allowed access to
entire system as root without a password.
Tested this on Caldera 2.3 and Corel 1.0, of which these systems gave the
Give root password for maintenance
(or type Control-D for normal startup):
I need this fixed ASAP to certify my systems.....
A system that allows arbitrary LILO arguments cannot be secured
by giving single-user mode a password; one can just boot with
'linux init=/bin/sh' and bypass all of those checks. The real
solution is to set /etc/lilo.conf up to not allow extra arguments
without a password. (And to force the BIOS to boot only from the
HD, and to password-protect the BIOS.)
What he said. ;)