lightdm-gtk was found to be affected by a vulnerability, which causes it to crash with no username entered and hitting the ENTER. The issue seems to be a local DoS due to NULL pointer dereference, which can be triggered by any unprivileged attacker requiring the intervention of an administrator to restart lightdm. When a greeter crashes the lightdm daemon exits. References: http://seclists.org/oss-sec/2014/q1/30 https://bugzilla.novell.com/show_bug.cgi?id=857303
Created lightdm-gtk tracking bugs for this issue: Affects: fedora-all [bug 1049422]
Created attachment 846727 [details] Patch for this vulnerability. Though this patch is for lightdm-gtk 1.3, it is reported to work on lightdm-gtk 1.6 as well.
Upstream report: https://bugs.launchpad.net/lightdm-gtk-greeter/+bug/1266449
lightdm-gtk-1.6.1-3.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
lightdm-gtk-1.6.1-3.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.