Security issues?

Topics: ASP.NET 2.0
Jan 12 at 9:54 AM
we are using blogengine with a MS Sql 2012 Database.
The database-password is strong (32-bit) and comments are off.
Nevertheless, for some time now, our blog is repeatedly hacked with link spam.
The spam content are directly into the database fields.

Is this a security or a configuration issue?
Any suggestions, how I can stop this?

Greetings from Berlin, Germany
Jan 12 at 2:14 PM
I have to check this out. Comments are public, but repository should check if they turned off and block API call.