Vino, possibly before 3.2, does not properly document that it opens ports in UPnP routers when the "Configure network to automatically accept connections" setting is enabled, which might make it easier for remote attackers to perform further attacks.
https://bugzilla.redhat.com/show_bug.cgi?id=678846
https://bugzilla.gnome.org/show_bug.cgi?id=594521
http://www.dslreports.com/forum/r25446313-Ubuntu-computer-hijacked-by-hacker~start=40