Page 1 of 1
OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 8:36 am
by Scorpion_69
So I figured I would leave OPENVPN up and running to test my connection....
After 4 hours I checked the INPUT/OUTPUT rates and found that 850mb of data was somehow transferred from my network.
I did a PORT security scan and was disturbed at what I found, the following PORTS are wide open......
22 ssh
23 telnet
119 nntp
135 rpc
139 net-bios
445 msft ds
So how do I close the ports that are open?
I disconnect the OPENVPN...run the PORT scan and everything is closed...
thnks

Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 12:27 pm
by janjust
can you pleeease be a bit more specific... on which machine are these ports open? on the client? on the VPN server?
on a windows client there are several protocols bound to the tap-win32 adapter - these protocols are then accessible via the VPN tunnel. Which version of OpenVPN are you using? Which client and server OS? what config files?
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 12:45 pm
by dropje
Are you doing a port scan on your public or private ip?
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 2:41 pm
by Scorpion_69
I am running windows 7
OPENVPN client latest version
no OPENVPN......I scan with
https://www.grc.com/x/ne.dll?bh0bkyd2 my network it totally secure NO OPEN PORTS
I connect with OPENVPN and scan again at
https://www.grc.com/x/ne.dll?bh0bkyd2 I show that all of the ports I listed are open.
Somehow with OPENVPN some &@#$% got 850mb of data off my network.
Please test exactly as I did and you will see the results.
Please let me know......
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 2:54 pm
by janjust
post your setup first - I'm still pretty sure this is a PEBKAC case
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 5:06 pm
by Scorpion_69
what setup are you referring to??
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 5:10 pm
by Scorpion_69
I am using OPENVPN and connecting to us2.giganews.com
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 5:16 pm
by Scorpion_69
sorry its us2.vpn.giganews.com
Re: OPENVPN SECURITY FLAW??
Posted: Wed Oct 26, 2011 9:22 pm
by janjust
I'm referring to the openvpn client config file on your windows machine; and , check the bindings of the tap-win32 adapter
Re: OPENVPN SECURITY FLAW??
Posted: Thu Oct 27, 2011 11:56 am
by Scorpion_69
client
dev tun
proto udp
remote us2.vpn.giganews.com 443
resolv-retry infinite
nobind
persist-key
persist-tun
persist-remote-ip
ca ca.vyprvpn.com.crt
tls-remote us2.vpn.giganews.com
auth-user-pass
comp-lzo
verb 3
auth SHA256
cipher AES-256-CBC
keysize 256
tls-cipher DHE-RSA-AES256-SHA:DHE-DSS-AES256-SHA:AES256-SHA
Tap binding is ok
Re: OPENVPN SECURITY FLAW??
Posted: Thu Oct 27, 2011 12:24 pm
by janjust
and how does this provider route your traffic to the internet? what does
http://www.whatismyip.com show? the IP address of the provider? in that case the open ports on the port scan can be open ports on the VPN provider server itself, NOT on your VPN client.
If you want to be sure, run wireshark on your VPN client , have it listen for tcp traffic port 445 and then rerun the port scan.
Also, how do you know 850 MB of data was transferred via your VPN?
Re: OPENVPN SECURITY FLAW??
Posted: Thu Oct 27, 2011 12:31 pm
by Scorpion_69
I know the 850mb was transferred because I checked the udp in/out status and that what it showed....and OPENVPN was running at the time
I will check out the other stuff shortly
Re: OPENVPN SECURITY FLAW??
Posted: Thu Oct 27, 2011 12:33 pm
by Scorpion_69
ok...without OPENVPN I get the IP address from my provider just fine........in the 99.xx.xxx.xxx range
When I run OPENVPN......I get a different address...in the 69.xx.xxx.xxx range
Re: OPENVPN SECURITY FLAW??
Posted: Thu Oct 27, 2011 2:08 pm
by janjust
so the port scan is now done against the IP of the VPN provider ; it might very well be that the VPN provider's server/router/nat box has the ports you mentioned open.
which udp in/out status did you check? 'netstat -s' ?
openvpn sends periodic keepalive messages, which over a couple hours might generate some traffic but it shouldn't be 850 MB.
Re: OPENVPN SECURITY FLAW??
Posted: Thu Oct 27, 2011 2:18 pm
by Scorpion_69
I agree with you......and sorry for only looking at OPENVPN as the issue...
I am thinking IT IS the VPN SERVER that has all the open ports.
I am sending the infor mation to the VPN service provider