The GTK version of ettercap uses a global settings file at /tmp/.ettercap_gtk and does not verify ownership of this file. When parsing this file for settings in gtkui_conf_read() (src/interfacesgtk/ec_gtk_conf.c), an unchecked sscanf() call allows a maliciously placed settings file to overflow a statically-sized buffer on the stack.
https://bugzilla.redhat.com/show_bug.cgi?id=643453
https://bugs.launchpad.net/ubuntu/+source/ettercap/+bug/656347
http://article.gmane.org/gmane.comp.security.oss.general/3660