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As of recently it has been discovered that most routers expose UPnP to the outside world, which is not good at all. This allows attackers "from the internet" to open ports in your routers.

It is recommended you DISABLE UPnP in your router. Below is a test to see if your router is vulnerable. Steve Gibson, the creator of the very popular "Shields-up" which scans your IP for open ports in your router has recently added a test for the upnp vulnerability. Simply click the link then click the "proceed" button. You will then see a button for the UPnP test. Good luck!

The Test

https://www.grc.com/x/ne.dll?bh0bkyd2

  On 03/02/2013 at 18:08, warwagon said:

It is recommended you DISABLE UPnP in your router.

No; It is recommened that you get a good router. I have UPnP on my router enabled and

  Quote

THE EQUIPMENT AT THE TARGET IP ADDRESS

DID NOT RESPOND TO OUR UPnP PROBES!

So either I have a good router or the test sucks.

  On 03/02/2013 at 18:20, Detection said:

I have uPnP enabled but still fine (Expected as much with DD-WRT though)

Capture.PNG

Correct this is a route test, not a computer test.

It's only recommended to disable UPnP on your routers if they don't pass that test, which means they are exposing you to the outer world.

Just passed the test on three touters with UPnP enabled. Two of them are running DD-WRT.

post-203976-0-34939600-1359915937.png

I disable it anyway. The fact that UPnP, by design, lets any application communicate with the router and open ports should make any security conscious user uneasy.

THE EQUIPMENT AT THE TARGET IP ADDRESS

DID NOT RESPOND TO OUR UPnP PROBES!

Why would you disable uPnP anyways? It allows internal hosts to dynamically open ports like XBL or PSN for gaming and voice. Without it you'd have to manually open every single port those services and similar ones use. Just keep your internal hosts clean.

  On 04/02/2013 at 08:12, trek said:

THE EQUIPMENT AT THE TARGET IP ADDRESS

DID NOT RESPOND TO OUR UPnP PROBES!

Why would you disable uPnP anyways? It allows internal hosts to dynamically open ports like XBL or PSN for gaming and voice. Without it you'd have to manually open every single port those services and similar ones use. Just keep your internal hosts clean.

Yeah I agree with keeping uPnP enabled also.

I ran many different servers over the years, long time ago now, so I had many ports opened for access, and that site's port tests always showed me as being safe and secure.

All depends on what type of security you're running on your computers.

There should be no issue with running UPnP/NAT-PMP on your router if it's properly configured, I knew mine would pass this test from the start since it exposes it's configuration in a good manner (It only allows hosts on the 192.168/16 subnet to create a forwarding rule, and said rule has to point at the host that requested it, otherwise it's rejected), and shows what ports are forwarded on what protocol.

Never mind the fact that the firewall should reject outside communication before it even gets to the UPnP/NAT-PMP daemon anyway, if it isn't being blocked you have bigger issues.

"Without it you'd have to manually open every single port those services and similar ones use."

So -- your talking a handful of ports at most.. UPnP is to allow unsolicted inbound traffic to get through your nat router. Traffic initiated by you, or in answer to your traffic is allowed.

Most people have no use of UPnP, it has been a nightmare since it was created -- who in their right mind thought, hey lets allow ports to be opened on your gateway/firewall without any sort of auth at all!!

And no UPnP should not be reachable via your public IP that is for damn sure.

  On 03/02/2013 at 18:32, warwagon said:

I disable it anyway. The fact that UPnP, by design, lets any application communicate with the router and open ports should make any security conscious user uneasy.

If you trust what's in your network and have the routers firewall up I don't see how it could.

^ the point is UPnP can remove your firewall settings. Without even a nod to you that its doing so, nor any sort of auth method to allow it.

There really needs to be some form of notification and auth to the mechanism - and then sure it would be a valid tool in opening firewall ports for the masses.

  On 04/02/2013 at 08:12, trek said:

THE EQUIPMENT AT THE TARGET IP ADDRESS

DID NOT RESPOND TO OUR UPnP PROBES!

Why would you disable uPnP anyways? It allows internal hosts to dynamically open ports like XBL or PSN for gaming and voice. Without it you'd have to manually open every single port those services and similar ones use. Just keep your internal hosts clean.

It would allow any malicious program to actively contact your router, open whatever ports it wants, and then transmit data through those ports all without your knowledge.... pretty big security hole if you ask me.

  On 04/02/2013 at 14:14, BeLGaRaTh said:

Steve Gibson, the person who creates the most FUD on the internet with his crazy rants and observations!!!

I'm not going to argue that the fact that he is crazy, which he probably is, but he is also very smart. And Facts do not = FUD.

Are you up to date on this UPnP issue? The typical way UPnP works is, an active program on one of the systems on your network will contact the router and open ports for whatever program/service to pass data through. Sounds ok right, well there is an exploit on a TON of routers that allows that request to be made from the OUTSIDE over the WAN, so if you have one of these affected routers, anyone outside your network, can open up ports into your network using a little bit of packet "magic". It's a pretty big deal.

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