Bug 562217 (CVE-2010-0414)

Summary: CVE-2010-0414 gnome-screensaver: loses its unlock dialog and keyboard grab sometimes when unplugging monitor
Product: [Other] Security Response Reporter: Ray Strode [halfline] <rstrode>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bressers, dallan, jlieskov, kas, kreilly, security-response-team, vdanen
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=moderate,source=redhat,reported=20100205,public=20100208,cvss2=6.2/AV:L/AC:H/Au:N/C:C/I:C/A:C
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-02-25 09:20:23 EST Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
Bug Depends On: 562318, 562882    
Bug Blocks:    
Attachments:
Description Flags
handle monitor topology changes better none

Description Ray Strode [halfline] 2010-02-05 11:19:54 EST
Under certain circumstances it is possible to circumvent the security of screen locking functionality of gnome-screensaver by changing the systems physical monitor configuration.

Steps to reproduce:

1) Lock screen
2) Move mouse to removable monitor
3) hit escape key to cancel unlock dialog
4) move mouse to bring up unlock dialog on new head
5) unplug monitor
6) quickly hit keys on the keyboard

At this point gnome-screensaver will either crash, or show a black screen.  If it shows a black screen then hitting "alt-f2" and then typing "pkill -f gnome-screensaver" will bring you to the session.
Comment 1 Ray Strode [halfline] 2010-02-05 11:21:20 EST
Created attachment 389117 [details]
handle monitor topology changes better

This addresses the issue by fixing the code paths that handle a monitor disappearing.
Comment 2 Ray Strode [halfline] 2010-02-05 17:16:21 EST
Note the only stable gnome release this affects is 2.28.

The code that caused this issue went into gnome-screensaver some time ago during the 2.24 devel cycle:

http://git.gnome.org/browse/gnome-screensaver/commit/?id=f6d3defdc

But we didn't get autoconfiguration of hotplugged monitors until gnome 2.28's devel cycle:

http://git.gnome.org/browse/gnome-settings-daemon/commit/?id=be513b3

Which is a prerequisite for triggering this bug.
Comment 3 Vincent Danen 2010-02-05 17:27:50 EST
This has been given the name CVE-2010-0414.
Comment 6 Vincent Danen 2010-02-08 11:20:43 EST
Embargo is lifted and this issue is public now.
Comment 9 Fedora Update System 2010-02-08 23:59:39 EST
gnome-screensaver-2.28.2-1.fc12 has been pushed to the Fedora 12 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 10 Ray Strode [halfline] 2010-02-19 14:53:16 EST
*** Bug 566774 has been marked as a duplicate of this bug. ***