Thursday, November 20, 2008

Default vsftpd on CentOS is dumb

This is pretty ironic, since the vs stands for "very secure".

From the top of /etc/vsftpd/vsftpd.conf:

# Allow anonymous FTP? (Beware - allowed by default if you comment this out).

This is the default configuration. Now, one of a couple things is going on here. Either the comment is lying, or the configuration flag is lying, or I'm terribly confused about what these words mean.

I figured that I'd check to see which was the case:

msimmons@newcastle:~$ ftp ftp1.test
Connected to ftp1.test.
220 (vsFTPd 2.0.5)
Name ( anonymous
331 Please specify the password.
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.

OKAY! This isn't good. In fact, it's a Bad Thing(tm).

Lets fix that. Ignoring the utterly stupid comment, I switch the flag to "NO", and restart the daemon. I try again, and I fail. Horray. Lets see what else I can find.

I log in as a pretend user, and I authenticate fine. I 'cd' to .. and do a directory listing, and what do I find, but all of the various client accounts. Our clients are confidential, which means that them seeing each other would be a Bad Thing(tm). I dig into the config again, and find this gem:

# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
# (default follows)

Great, so apparently, I just need to find and flip the flag on chroot_local_user. Of course, it doesn't exist in the file. I create it, set it to "YES", restart the daemon, and things are working the way they should.

The question in my mind is why an FTP daemon that bills itself as Very Secure comes with such an asinine configuration. There are occasions where chrooting the ftp users isn't called for, but there are relatively few occasions that require anonymous FTP access. I can't understand why they wouldn't have shipped a secure config and then made people unsecure it, as opposed to the way it is now. Really hard to believe.

I suppose it is possible that the distro maintainers are responsible, but it's still stupid.