OpenVPN makes other ports visible?
I have a question about security, I'm wondering if anyone here knows.
Recently I was experimenting with OpenVNP, and was running a VPN server off of port 1194. My cable modem/router was configured to do port forwarding from external port 1194 to my server's port 1194, so this service was exposed to the internet.
After leaving this service running for the weekend, I was surprised to find today (Monday) that my server had been hacked, due to a brute force attack on the ssh service running on port 22. This was surprising to me because I did not believe that port 22 was exposed to the internet.
My question is, does anybody know how this could have happened? Does OpenVPN somehow make other ports visible? The server was configured to do ethernet bridging (i.e. "tap" not "tun").
Also, because in the past I've occasionally recieved off point responses to posts, the question I'm interested in is how port 22 could have been exposed to the internet given the above configuration (i.e., port forwarding to OpenVPN on 1194 only), so if the response isn't an attempt to answer this, please do not respond. For example, if your response is "regardless of your configuration, you should always secure ssh services etc. etc." please do not respond.
Thanks so much in advance.