ESP8266 - How to know if incoming connection is from AP or station network?
I don't think the default AT firmware allows to automatically reject packets because that would probably require a higher degree of control, but looking at the Expressif documentation about the AT command set I've discovered you can actually retrieve the remote address rather than the local one, just by using the same command you were using but with a different parameter

AT+CIPDINFO=1


Not sure though this actually might solve your problem.