|They are both related to networked devices which you probably don't use.|
There is absolutely no fear of causing any major problem by disabling them and as Tufenuf said it is quite easy to enable them again if it doesn't help. To this end it would be best to use the manual method and note the current settings before changing them.
SSDP will show as "SSDP Discovery Service" and
uPNP will show as "Universal Plug and Play Device Host".
If it makes you feel better, both are disabled on my machine. If you Google the above titles (given in quotes) you will get a full description.
some other bloke...