There are a few handy tools for checking to see if your router is vulnerable to exploitation, and if there are any vulnerable devices on the network.
Some simply look at your model and version then see if a CVE has been issued for it.
Others will also test for vulnerabilities that can actually be exploited.
RouterCheck is available for Android and Windows (beta)
Avira Home Guard (Windows and Android)
Bitdefender Smart Home Scanner (Windows)
Router Security guides for many router related topics