Comment on Backdoors in D-Link’s backyard by Michael
Another possible fix, depending on the revision of the hardware, might be to install a custom firmware on it. e.g. OpenWrt:
https://openwrt.org/toh/start?dataflt%5BBrand*%7E%5D=d-link&dataflt%5BModel*%7E%5D=dir-620
More information: Comment on Backdoors in D-Link’s backyard by Michael
Story added 27. May 2018, content source with full text you can find at link above.