Re: vlock vulnerability in RedHat 7.0

[Trond Eivind Glomsrød <teg () REDHAT COM>]

Bartlomiej Grzybicki <bgrzybicki () morliny pl> writes:

> I've tried to lock all virtual consoles
> in RedHat 7.0 using vlock, which
> is delivered with this release of RedHat.
>
> If user root locks all consoles - it's no problem,
> but if normal user locks consoles then
> anybody can unlock without typing a password.
>
> Try to use it in the following way:
>
> 1. logon as an ordinary user on tty1
> 2. logon as root on tty2
> 3. Type on tty1 vlock -a
> 4. All consoles will be locked.
> 5. When vlock asks for password
> press ENTER and don't release the key
> until you see message 'broken pipe'.
> 6. If you see it all two consoles are unlocked.

How is your system configured? I can't reproduce this.

--
Trond Eivind Glomsrød
Red Hat, Inc.