For years we've had a underused CVS server at the location of cvs.snort.org. While going back through our assets and taking a look at what we were using and not using, we noticed that cvs.snort.org was barely used. The server was very old and ran an older OS, so at this point it was becoming more of a liability to keep it up.
This wasn't even a live CVS server and it was only synced when we did a Snort release.
In fact, the only time it was ever used was when people Google a phrase and wind up in the code repository to reference something on a Snort list. Since the posting of the manual at http://manual.snort.org I felt the server was unneeded and it is now in the process of being decommissioned. In fact, it's already been brought down.
If people still need the CVS, let me know, and we will explore ways to make the code public in a CVS form again. You can still download the full source code of Snort at https://www.snort.org/downloads.