> its the generic one

For whatever linux distribution you are using..., its not
the projects build on SourceForge for example. I suspect some one (who
maintains Firebird for your Linux distro), may have been over zealous with the security.
Any user who is part of the group firebird should be able to use firebird in embedded
mode.

Regards
Paul


# ls -l /var/lib/firebird/system/security2.fdb
-rw------- 1 firebird firebird 1064960 Aug 14 16:34 /var/lib/firebird/system/security2.fdb
# rpm -qa | grep fire
firebird-classic-common-2.5.5.26952.0-2.el6.x86_64
firebird-libfbembed-2.5.5.26952.0-2.el6.x86_64
firebird-classic-2.5.5.26952.0-2.el6.x86_64
firebird-libfbclient-2.5.5.26952.0-2.el6.x86_64
firebird-2.5.5.26952.0-2.el6.x86_64
firebird-filesystem-2.5.5.26952.0-2.el6.x86_64