WIFI security error message CVE-2012-5958 from Avast Antivirus

My router is a talktalk HG 533 running Firmware version 1.20t. My Avast antivirus software via its WiFi inspector has started reporting that the router has a vulnerability code ID: CVE-2012-5958.
The Avast software is at version level 17.9.2322 which was released in December 2017.
I am not sure what this error code means but all previous versions of Avast have not detected any problems.
So can anyone please tell me if this is a possible false positive or am I looking at a potential problem?

I am also getting this message, I hope someone can reply regarding this. My computer is running slower than usual, MacBook Pro. Just downloaded sierra…
Buffer overrun
The device is vulnerable to hacker attacks. For more info see the corresponding vulnerability ID. An upgrade of the device’s software/firmware may fix the issue.
CVE-2012-5958

Issue discussed and answered earlier here: https://forum.avast.com/index.php?topic=210957.0

polonus

Thanks to both of you for your replies. I had already checked the topic that polonus has indicated before posted on this forum.
However the event occurred on a different router in 2014. I have had no problems until this latest Avast update. It may be that a router firmware upgrade would cure the problem, but did the latest Avast upgrade include something new that was not checked for previously?
Also, the android version of Avast on my smartphone does not indicate any WiFi problems.