NetworkManager: Console user can escalate to root via newlines in ifcfg-rh connection name

Incomplete blacklist vulnerability in the svEscape function in settings/plugins/ifcfg-rh/shvar.c in the ifcfg-rh plug-in for GNOME NetworkManager 0.9.1, 0.9.0, 0.8.1, and possibly other versions, when PolicyKit is configured to allow users to create new connections, allows local users to execute arbitrary commands via a newline character in the name for a new network connection, which is not properly handled when writing to the ifcfg file.