despite of the fact if the statement makes sense or not, it should definitely not result in a FB crash

select cast(rdb$db_key as integer) from rdb$database

firebird log reports

HKNB9 Tue Jan 31 21:49:44 2023
Access violation.
The code attempted to access a virtual
address without privilege to do so.
This exception will cause the Firebird server
to terminate abnormally.

reproducible always on fb4 but I also think on an older version