Firewall Concerns

[DrB0b]

Issue:
Installing a program on server which hands out a key to the client to use to enable a program to run. Client's program would not run so I turned off Server firewall, then it would function. Tried enabling each "off" rule in firewall settings one at a time with firewall on and clients program wouldn't run. Found out it was using UDP to communicate to the server and get the key it needed. Called the company that made the software and found which specific port UDP was using, we will call it 9000 for reference. Set up a new rule allowing UDP on port 9000 to be let through. In these settings you can tell it which program, that's using UDP on that Port, to let through - this I cannot do. I can allow any program that queries UDP on Port 9000 through or none right now.

Question:
Is this a big security issue? Any program that queries UDP on Port 9000 would bypass my firewall. Since its on a random port, I don't think this will cause a big hole to exploit but I would like to hear others input.
Thanks

"Silence is golden, duct tape is silver...

 

[linney]

See the paragraph "Security" in this article.

Take Total Control Of Your Networking With .NET And UDP

http://msdn.microsoft.com/en-us/magazine/cc163648.aspx

http://www.google.com.au/search?hl=...&gs_upl=5218l8876l0l2l2l0l0l0l0l325l608l2-1.1

It might pay you to ask this question in the Server Forums too.

http://www.tek-tips.com/threadminder.cfm?pid=1674

http://www.tek-tips.com/threadminder.cfm?pid=931

 

[DrB0b]

Thanks Linney,
I will post in the server section too.
As far as implementing UDP, it is used within a program straight from the manufacturer not allowing me to maneuver how it uses the protocol. The last server they had this setup on just had the firewall completely disabled so I guess what I have is a lot more secure then that.
Thanks

"Silence is golden, duct tape is silver...

 

[BadBigBen]

if the server and all the clients are sitting behind a hardware firewall (most routers have these), then there is less of a chance that something outside that network would query port 9000...

meaning basically that that port is only open to machines inside of that network...

now if you really want to be paranoid, then set up a VM with that application, then clone that VM and save it out to a USB drive, once that is done, remove the USB, and run the VM... now if something gets through and trashes that install, you will be up and running in as quick as you can delete that bunged VM and recopy the stashed VM back from the USB...


Ben
"If it works don't fix it! If it doesn't use a sledgehammer..."
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Only ask questions with yes/no answers if you want "yes" or "no"