I decided to check out my home through the BullGuard IOT Scanner. I used my Android phone and the Opera browser, and it came up that I was vulnerable: ports 22, 8090, 8098, and 9100 were all reported as "public," via Shodan.
I then opened my laptop and checked it, and it came up as "Not Public." Then I turned on my phone's WiFi hotspot, and checked my laptop again through the phone. "Not Public."
Then I checked again from my phone, this time using Firefox. "Not Public." However, when I checked again using Opera I got the same results as the first time. So the only time I showed up as "public" was when using Opera on my phone.
Is Opera unnecessarily exposing me when I use it? Should I dump Opera? Or is there a legitimate explanation for this?
Re: Hax's questions
- The phone uses IPv4, but the laptop uses IPv6. I think the router prefers IPv6, but I'm not clear on the whole v4/v6 thing. When I check my IP with the phone I get a v4 response, and a v6 from my laptop.
- Everything was done on my WiFi network, which is behind the firewall on the router. I run my own home VPN, so I definitely have ports forwarded; however, they aren't any of the ports that BullGuard detected. I have the VPN set up with PKI and an HMAC key, and I don't use 22 for SSH.
Re: Franz - I know that Opera offers a free VPN, but I think it requires a separate program. It may be that their browser is listening on those ports (but why not 1194?) just in case, but how is the scanner seeing those ports when they're located BEHIND the firewall?
Everything is behind a firewall for these tests, so how can the scanner see open ports for one device operating behind the firewall and not the others, and then only for one program?
I'm not familiar with Shodan or nmap, but I'll explore your suggestions. (Edit: Shodan returned no results for my home IPv4). I don't see how this is an issue with the Comcast router, but the GRC Shields Up scan reports a ping response from those ports, as well as some other random higher-numbered ports their standard scan doesn't check. I put my phone in airplane mode, but the results remained constant. There is nothing in the router settings indicating that any ports are open except for those I've manually opened. But even if the router is partially to blame, why does Opera fail and both Firefox and Chrome pass (on the phone), and the laptop passes?