The Firebird Project releases important security updates addressing a remote stack buffer overflow
discovered in the Firebird Server during March, 2013.
This vulnerability allows an unauthenticated user to crash the server and opens a gate for remote code execution, so it's highly recommended to upgrade your server installations. Security updates are available for Firebird 2.5.2
and Firebird 2.1.5
versions. They don't include any changes other than the bugfix for the aforementioned buffer overrun.