I too am having the same problem, also with a Bell Home Hub 2000 provided by my ISP . The actual make and model is a Sagemcom Fast 5250. The information available on the web for this particular vulnerability (ZSL-2014-5208), seems to point to a particular Netgear router. The information in the avast! Home Network Scan indicates the router may need a software/firmware update.
I first contacted my ISP who assured me that it couldn’t possibly be a problem with the modem/router ???. I performed both a cold and warm boot on the modem/router and it did upgrade the firmware. I ran the avast! network scan again and it still reported the issue. Tried rebooting the computer – same thing. I contacted avast! Technical Support, but they were not able to tell me whether it was likely a false positive or an actual vulnerability. It seems that the Name and DNS Name that avast! lists for the router in the network scan has changed (network possibly hacked), but I can’t say for sure.
Does anyone have any information on this vulnerability being reported on this modem/router (i.e. is it a false positive or an actual vulnerability, and have there been any exploits)? 
Thanks in advance for any help.