Avast Antivirus Reporting Open Port Vulnerability

[Fandalthorn]

When I perform a Network Security Check through Avast! Antivirus, it reports that my Ignite modem has an open port that makes my router vulnerable to attacks from the Internet. I have tried to research this, but really haven't gotten anywhere on how to resolve it.

It's saying that Port 7547 is open and that I should go into the router settings and close it. However, I have read that this port is open so that Rogers Technical Support can use it to access my modem/router to help troubleshoot Internet issues.

I also read that this port can be set to "hidden" and invisible to any possible attacks but therefore still accessible by Rogers should any diagnostics be required in the future. However, when I try to do anything in the Port Forwarding, there is only a link to Rogers, there is no settings that I can see.

My previous modem, before I upgraded to Ignite, did not report such a vulnerability when doing a Network Scan. 

I'd really like advice/information on how to resolve this, as I am concerned about the modem's security. I did call Internet Technical Support, however, they were only able to send me a link on how to access Port Forwarding.

***Added Labels***

[stu593]

I am going to be following this thread as Rogers just upgraded me to Ignite today.  When I use Shodan I get the same open port showing as you have reported. In my previous Rogers setup, there were no open ports. Interestingly, ShieldsUp is showing that port 135 is now open. Looking forward to hearing back on this thread and thanks for posting.

[RogersCorey]

Hello @Fandalthorn and @stu593!

We do reserve some ports for our use and it's not possible to manually close these ports using the modem settings.

I apologize for any inconvenience. I know some customers do wish to have full control over their ports.

Regards,

RogersCorey

[Fandalthorn]

But, what about port vulnerability? I'm concerned that having this open port opens my router to be susceptible to internet hacking.

[Bplayer · Accepted solution]

There is a very small but negligeable exposure. This would be common exposure for millions of Comcast & Rogers user of this modem. You have some options:

1.Live with the exposure (there are greater risks connecting with the internet than this).
2. Get you own modem/router and put it behind the Rogers Gateway. Lots to configuration to manage in this setup (there are posts here on how to do that).
3. Switch to a service provider that allows you to configure the equipment to your liking. It is a matter of compromises and trade-offs.

[Fandalthorn]

Ok, well thanks for the reply and information. 

[Messor_Animae]

The CWMP port 7547 vulnerability is not trivial: https://blog.avast.com/avast-home-network-security-scns-routers-to-reveal-weaknesses

Serious problem. Rogers needs to have Comcast fix that vulnerability in the Ignite modem's firmware. 

[Gdkitty]

Does avast find the open port from looking from the OUTSIDE (internet) or from internal?

Just wondering, if its open, but maybe only on the internal side from rogers?