Yes, be concerned. Secure passwords really don't matter in this case.
UPnP is on many devices including Windows. However, focus on these two devices: your router and cable modem. These are the two you can most likely disable UPnP on and which should be the easiest and most effective security measure.
The other devices may not have this UPnP setting accessible, or may require more involved tricks such as how to disable UPnP on windows XP:
»tweaks.com/windows/37087/complet ··· ay-upnp/
Most routers will have an easy way to disable UPnP. Just check out the manual for your router.
Supposedly there is a scanner that can indicate if there is a problem but it requires Java Runtime:
»www.rapid7.com/resources/free-se ··· 2013.jsp
NOTE: this software may not be able to properly check your cable modem if it's in behind the router. (eg: Coax line from Brighthouse -> Cable Modem -> Router)