CVE-2013-7220: Medium severity Gnome gnome-shell vulnerability
Fedora 18 is found to be vulnerable to the blind command execution on the lock screen, and Fedora 19 is found to execute command through "Enter the Command" dialog box at the lock screen.
The issue is that in Fedora 18, when you open either the Activities panel or "Enter a command" dialog box (Alt+F2), and then lock the screen or let the screensaver lock the screen, then if you start typing on the lock screen, instead of entering the password or just waking the screen, it actually types anything you type on the Activities panel or "Enter a command" dialog box, so anyone who enters a executable command and press enter, the command is executed even when the screen is locked.
In Fedora 19, the "Enter the Command" dialog box is visible even after you lock the screen, so anyone can write the commands in the box and execute them over a locked screen.
The issue is still to be fixed and tested on Gnome Fedora 18 and 19 machines. KDE version were not found to be affected.
Other sources
js/ui/screenShield.js in GNOME Shell (aka gnome-shell) before 3.8 allows physically proximate attackers to execute arbitrary commands by leveraging an unattended workstation with the keyboard focus on the Activities search.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
GNOME Shell (gnome-shell) / js/ui/screenShield.jsto a version that resolves this vulnerability.Fixed in 3.8 - Configuration
Update GNOME Shell so that js/ui/screenShield.js is not vulnerable (GNOME Shell before 3.8 is affected); after upgrading, verify that typing on the lock screen no longer carries over Activities/Alt+F2 command input and cannot execute commands while locked.
GNOME Shell (gnome-shell) / screen lock behavior screenShield.js = patched (3.8 or later)
Event History
Frequently Asked Questions
What is the severity of CVE-2013-7220?
CVE-2013-7220 is considered to be of medium severity due to its potential for exploitation in a user-interactive environment.
How do I fix CVE-2013-7220?
To fix CVE-2013-7220, update your GNOME Shell to a version later than 3.7.92.
Which versions of GNOME Shell are affected by CVE-2013-7220?
GNOME Shell versions from 3.0.0 up to 3.7.92 are affected by CVE-2013-7220.
What type of vulnerability is CVE-2013-7220?
CVE-2013-7220 is a blind command execution vulnerability that can occur via the lock screen.
Is CVE-2013-7220 present in Fedora 19?
Yes, CVE-2013-7220 is reported to also be present in Fedora 19 through the 'Enter the Command' dialog box.