Are You Sharing Your files With the Entire Internet?

Over the last few years, we have all become accustom to Microsoft’s steady stream of security vulnerabilities and corresponding patches. Most of the time these security vulnerabilities are unchecked buffers, which could theoretically be used for remote code execution.

Every once in a while though, a security vulnerability comes along that is so scary that it defies belief. This article is about just such vulnerability. If this story doesn’t convince you that you should enable automatic updates for Windows, then nothing will.

The problem has to do with the way that the Windows firewall interacts with Windows file sharing. The reason that the problem exists is that when ever a user enables file and print sharing, Windows automatically opens a port in the firewall which makes the shared resource available across the local network. This in and of itself is not a problem.

The problem comes into play with the definition of the local network. Some Internet Service Providers require their clients to run a configuration in which the Internet essentially becomes the computer’s “local network”.

This means that if someone were using one of these Internet Service Providers and they enabled file sharing, then anyone on the Internet would be able to access the shared files. Read more...