Is it safe to open port 3306 in Firewall for external MySQL Connection

Question

This may be more of a server question, but it's development related, and since I'm a developer I hope it's appropriate here.

I want to connect to a MySQL DB that is hosted with an ISP using something like TOAD, Navicat or HeidiSQL. I was told by the ISP that MySQL is listening on port 3306 but the hardware firewall is not allowing outside connections to access (only localhost). I have the option of giving them IPs to add to the firewall, but that's not ideal b/c I work from home or on the road mostly so my IP is always changing. If I open this up am I asking for trouble? Are there any measures besides adding my IP to an IP table that I could do to mitigate the risks?

Answer 1

Generally restricting MySQL access to an ip address is a good idea. There can be some security concerns but a good firewall should mitigate some of them. They would have to create an additional MySQL user for you since MySQL does not allow multiple hosts (unless there's a wildcard) per user. You could request multiple users, one for each host that you are connecting from or even do partial hosts (eg. %.google.com).

An alternative solution is to create a ssh tunnel from your machine so that you can connect locally.

Here's a good article on how you can create a ssh tunnel with MySQL.

http://www.howtogeek.com/howto/ubuntu/access-your-mysql-server-remotely-over-ssh/

Answer 2

DO NOT open 3306.

Instead, do what every other server does: Open port 22 for secure ssh connection, then once logged on, connect locally to mysql.

Answer 3

While you can keep your authentication secure by being very careful with grants and requiring SSL. You have no protection against potential undiscovered exploits that may be used.

Some SQL clients have an SSH tunnel option which is a better idea.

Answer 4

Since you mentioned Navicat, check out its HTTP tunnel feature. If you name/locate that tunnel endpoint obscurely and use HTTP authentication on the file itself (in addition to your MySQL authentication), you eliminate all but the most targeted attacks.