Bug 901586

Summary:	pKill -9 gnome-shell allow one to log on the computer without entering password
Product:	[Fedora] Fedora	Reporter:	Raphaël Flores <raf64flo>
Component:	gnome-shell	Assignee:	Owen Taylor <otaylor>
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	urgent	Docs Contact:
Priority:	unspecified
Version:	18	CC:	admiller, fmuellner, otaylor, samkraju, tiagomatos, walters
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-01-27 16:51:38 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Raphaël Flores 2013-01-18 15:13:19 UTC

User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20100101 Firefox/17.0
Build Identifier: 

Description of problem:
If TTY terminal is already logged in, anyone having physical access to the keyboard can bypass the lock screen.

Version-Release number of selected component (if applicable):
Fedora 18
GNOME Shell 3.6.2

How reproducible:
Login tty2, come back to graphical session (TTY1), lock screen, kill gnome-shell session, restart it specifying correct display, comme back to TTY1, you're logged.

Reproducible: Always

Steps to Reproduce:
1. Log in gnome-shell session at startup
2. Go to TTY2 (Ctrl+Alt+F2), log same user
3. Come back to TTY1 (Ctrl+Alt+F1)
4. Lock screen (Ctrl+Alt+l)
5. Go back to TTY2 and execute following command:
  $ pkill -9 gnome-shell && /usr/bin/gnome-shell -r -d :0
6. Come back to TTY1

Actual Results:  
I've bypassed the lock screen and got logged in.

Expected Results:  
Should come back on locked screen.

This bug is conditionned to user misattention but in some case, if TTY2 is already logged in, anyone can access to the graphical session. I believe this is a severe security issue.

Comment 1 Rui Matos 2013-01-27 16:51:38 UTC

As mentioned by Giovanni in gnome's bugzilla this isn't a bug.