This indicates an attempt to exploit one of several buffer-overflow vulnerabilites in Borland Interbase.
Borland InterBase is vulnerable to multiple remote buffer-overflow exploits. This is due to the application's failure to properly bounds-check user-supplied input before copying it into an insufficiently sized memory buffer.
Borland Interbase 2007 SP2
Borland Interbase 2007
These issues have been addressed in the latest version of Firebird (Firebird 188.8.131.528-1).