Firebird 1.5.2.4731 installs (1) fb_lock_mgr, (2) gds_drop, and (3) fb_inet_server with setuid firebird permissions, which might allow local users to gain privileges via a buffer overflow as identified by CVE-2006-1240, or possibly other vulnerabilities.
Buffer overflow in Firebird 1.0.2 and other versions before 1.5, and possibly other products that use the InterBase codebase, allows local users to execute arbitrary code via a long INTERBASE environment variable when calling (1) gds_inet_server, (2) gds_lock_mgr, or (3) gds_drop.