CVE-2014-0979

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

Updated lightdm-gtk-greeter package fixes security vulnerability:

lightdm-gtk-greeter uses the lightdm-gobject API incorrectly and does not handle lightdm_greeter_get_authentication_user() returning NULL when the username of the previous authentication is invalid resulting in a NULL pointer dereference in start_authentication(). This constitutes a local denial of service which can be triggered by any unprivileged attacker requiring the intervention of an administrator to restart lightdm (CVE-2014-0979).

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.