oss-sec mailing list archives
Re: Screen locking programs on Xorg 1.11
From: Tim Zingelman <tez () netbsd org>
Date: Thu, 19 Jan 2012 17:35:23 -0600
On Thu, Jan 19, 2012 at 1:18 PM, Florian Weimer <fw () deneb enyo de> wrote:
I recently found out that it is possible to kill a screensaver/screen locker program on the latest version of Xorg (1.11 shipped with archlinux, debian wheezy..) using the Ctrl+Alt+Multiply key binding.This used to be, uhm, common knowledge: | Option "AllowDeactivateGrabs" "boolean" | This option enables the use of the Ctrl+Alt+Keypad-Divide key | sequence to deactivate any active keyboard and mouse | grabs. Default: off. | | Option "AllowClosedownGrabs" "boolean" | This option enables the use of the Ctrl+Alt+Keypad-Multiply key | sequence to kill clients with an active keyboard or mouse grab as | well as killing any application that may have locked the server, | normally using the XGrabServer(3x) Xlib function. Default: off. | | Note that the options AllowDeactivateGrabs and AllowClosedownGrabs | will allow users to remove the grab used by screen saver/locker | programs. An API was written to such cases. If you enable this | option, make sure your screen saver/locker is updated. <http://www.x.org/archive/X11R6.8.1/doc/Xorg.1.html> The API in question appears to be XF86MiscSetGrabKeysState: <http://cvsweb.xfree86.org/cvsweb/xc/programs/Xserver/hw/xfree86/XF86Config.man?hideattic=0#rev1.6>
Given this additional information isn't this a vulnerability issue in the various screen lock applications rather than an issue with the Xorg server? - Tim
Current thread:
- Screen locking programs on Xorg 1.11 Gu1 (Jan 18)
- Re: Screen locking programs on Xorg 1.11 Michael Gilbert (Jan 18)
- Re: Screen locking programs on Xorg 1.11 Michael Gilbert (Jan 18)
- Re: Screen locking programs on Xorg 1.11 Kurt Seifried (Jan 18)
- Re: Screen locking programs on Xorg 1.11 Sebastian Pipping (Jan 18)
- Re: Screen locking programs on Xorg 1.11 Yves-Alexis Perez (Jan 19)
- Re: Screen locking programs on Xorg 1.11 Florian Weimer (Jan 19)
- Re: Screen locking programs on Xorg 1.11 Tim Zingelman (Jan 19)
- <Possible follow-ups>
- Re: Screen locking programs on Xorg 1.11 Gu1 (Jan 19)
- Re: Screen locking programs on Xorg 1.11 Michael Gilbert (Jan 18)