[arch-general] FS#28008 - Bypass screensaver/locker program on xorg 1.11 and up

[David J. Haines]

On Jan 20, 2012 2:10 AM, "Florian Pritz" <bluewind at xinu.at> wrote:
>
> On 20.01.2012 02:18, David J. Haines wrote:
> > On Thu, Jan 19, 2012 at 8:08 PM, Tavian Barnes
> > <tavianator at tavianator.com> wrote:
> >> On 19 January 2012 18:23, Dmitry Korzhevin <dkorzhevin at lsupport.net>
wrote:
> >>> a funny bug in the Xorg server that could allow attackers with
physical
> >>> access to a machine to bypass the screensaver/screen locker program.
> >>> Most people use those programs to lock their computer when they are
> >>> away. On Gnome, gnome-screensaver is responsible for this. On KDE,
> >>> kscreenlocker is. There is a wide variety of smaller tools doing the
> >>> same thing, e.g. slock, slimlock, i3lock...
> >>>
> >>> Read more:
> >>>
http://gu1.aeroxteam.fr/2012/01/19/bypass-screensaver-locker-program-xorg-111-and-up
> >>>
> >>> ctrl+atl+*(on num lock keyboard) confirmed and work in arch linux.
> >>
> >> IMO, it's not an X.Org or configuration bug, it's a bug in all the
> >> screen lockers.
> >>
> >> http://seclists.org/oss-sec/2012/q1/217
> >>
> >> --
> >> Tavian Barnes
> >
> > No Happy Hacking Keyboard (1996 IBM Model M, baby!), but I do use a
> > custom keyboard layout that allows me to type international letters
> > and switch entirely to a phonetic Cyrillic layout.
>
> Please check if your custom layout contains the string "XF86_ClearGrab"
> (maybe also without the underscore) and if yes, replace it with
> "NoSymbol". Don't forget to reload it afterwards.
>
> --
> Florian Pritz
>

I will be sure to do that, but that does seem only to address the symptom
and not the underlying sickness. As I intimated earlier, this is most
likely an issue for the app (or more precisely screen locking app) writers.

Thanks for what looks to be a great intirim solution!