Is this the same problem as: Security Warning From Netgear. 23.06.2020 ?
Regardless, the same advice applies: disable remote management (assuming that in order to exploit this problem remotely does require that remote management be enabled).
My home network equipment honeypot 
is not (yet) seeing any attempts on upgrade_check.cgi
This can sometimes be complicated because there are examples where a manufacturer has declared something EOL and then, later on, a vulnerability emerges that is so damaging to the brand that the manufacturer fixes it even in EOL equipment.
One way of tackling this is via warranty. That would hopefully stop vendors selling equipment that is already EOL (as mentioned in the article).
If home network (internet gateway) equipment were capable of periodically checking for available updates, a manufacturer could at least use that as a means of advising owners when the equipment went EOL.
This won’t work for air-gapped home network equipment. However that would be niche.
Don’t get me started on that …
